U.S. patent application number 08/870794 was filed with the patent office on 2001-09-20 for phosphonooxymethyl ethers of taxane derivatives.
Invention is credited to GOLIK, JERZY, KADOW, JOHN F., KAPLAN, MURRAY A., LI, WEN-SEN, PERRONE, ROBERT K., THOTTATHIL, JOHN K., VYAS, DOLATRAI, WITTMAN, MARK D., WONG, HENRY, WRIGHT, JOHN J..
Application Number | 20010023255 08/870794 |
Document ID | / |
Family ID | 27493620 |
Filed Date | 2001-09-20 |
United States Patent
Application |
20010023255 |
Kind Code |
A1 |
GOLIK, JERZY ; et
al. |
September 20, 2001 |
PHOSPHONOOXYMETHYL ETHERS OF TAXANE DERIVATIVES
Abstract
The present invention concerns antitumor compounds. More
particularly, the invention provides novel taxane derivatives,
pharmaceutical compositions thereof, and their use as antitumor
agents.
Inventors: |
GOLIK, JERZY; (SOUTHINGTON,
CT) ; VYAS, DOLATRAI; (MADISON, CT) ; WRIGHT,
JOHN J.; (GUILFORD, CT) ; WONG, HENRY;
(DURHAM, CT) ; KADOW, JOHN F.; (WALLINGFORD,
CT) ; THOTTATHIL, JOHN K.; (ROBBINSVILLE, NJ)
; LI, WEN-SEN; (MARLBORO, NJ) ; KAPLAN, MURRAY
A.; (SYRACUSE, NY) ; PERRONE, ROBERT K.;
(LIVERPOOL, NY) ; WITTMAN, MARK D.; (CHESHIRE,
CT) |
Correspondence
Address: |
DAVID M MORSE
PATENT COUNSEL WALLINGFORD
BRISTOL MYERS SQUIBB COMPANY DEPT 851
PO BOX 5100
WALLINGFORD
CT
064927660
|
Family ID: |
27493620 |
Appl. No.: |
08/870794 |
Filed: |
June 6, 1997 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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08870794 |
Jun 6, 1997 |
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08427502 |
Apr 24, 1995 |
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08427502 |
Apr 24, 1995 |
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08245119 |
May 17, 1994 |
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08245119 |
May 17, 1994 |
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08154840 |
Nov 24, 1993 |
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08154840 |
Nov 24, 1993 |
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08108015 |
Aug 17, 1993 |
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08108015 |
Aug 17, 1993 |
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07996455 |
Dec 24, 1992 |
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Current U.S.
Class: |
514/449 ;
549/510; 549/511 |
Current CPC
Class: |
C07D 305/14 20130101;
C07F 7/1804 20130101; C07F 9/65512 20130101; C07D 409/12 20130101;
H01L 21/4839 20130101; C07D 407/12 20130101; C07F 9/65586
20130101 |
Class at
Publication: |
514/449 ;
549/510; 549/511 |
International
Class: |
A61K 031/337; C07D
35/14 |
Claims
We claim:
1. A compound having the formula
T--[OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).s- ub.2].sub.n (A) wherein
T is a taxane moiety bearing on the C13 carbon atom a substituted
3-amino-2-hydroxypropanoyloxy group; m is 0 or an integer from 1 to
6 inclusive; n is 1, 2 or 3; or a pharmaceutically acceptable salt
thereof.
2. A compound of claim 1 wherein said taxane moiety is further
characterized as containing at least a C11-C12 double bond, C1
hydroxy, C2 benzoyloxy, C4 acetyloxy, C9 oxy, and C5-C20
oxetane.
3. A compound of claim 1 wherein said taxane moiety is derived from
a residue having the formula 114wherein R.sup.2e' is hydrogen and
R.sup.2e hydrogen, hydroxy --OC(O)R.sup.x, or --OC(O)OR.sup.x;
R.sup.3e is hydrogen, hydroxy, --OC(O)R.sup.x, --OC(O)OR.sup.x or
C.sub.1-6alkyloxy; one of R.sup.6e or R.sup.7e is hydrogen and the
other is hydroxy or --C(O)OR.sup.x; or R.sup.6e and R.sup.7e
together form an oxo group; R.sup.x is C.sub.1-6 alkyl optionally
substituted with one to six same or different halogen atoms,
C.sub.3-6 cycloalkyl, C.sub.2-6 alkenyl or hydroxy; or R.sup.x is a
radical of the formula 115wherein D is a bond or C.sub.1-6 alkyl;
and R.sup.a, R.sup.b and R.sup.c are independently hydrogen, amino,
C.sub.1-6 alkylamino, di-C.sub.1-6alkylamino, halogen, C.sub.1-6
alkyl, or C.sub.1-6 alkoxy.
4. A compound of claim 1 wherein said substituted
3-amino-2-hydroxypropoyl- oxy group is derived from a residue
having the formula 116wherein R.sup.1e is hydrogen or
--C(O)R.sup.x, --C(O)OR.sup.x; R.sup.4 and R.sup.5 are
independently C.sub.1-6 alkyl, C.sub.2-6 alkenyl, C.sub.2-6
alkynyl, or --Z--R.sup.6; Z is a direct bond, C.sub.1-6 alkyl or
C.sub.2-6 alkenyl; R.sup.6 is aryl, substituted aryl, C.sub.3-6
cycloalkyl, or heteroaryl; p is 0 or 1; and R.sup.x is as defined
previously.
5. A compound of claim 1 wherein said taxane moiety is further
characterized as containing at least a C11-C12 double bond, C1
hydroxy, C2 benzoyloxy, C4 acetylo , C9 oxy, and C5-C20 oxetane;
and said substituted 3-amino-2-hydroxypropanoyloxy group is derived
from a residue having the formula 117wherein R.sup.1e, R.sup.4,
R.sup.5 and p are as previously defined.
6. A compound of claim 1 having the formula 118wherein R.sup.1 is
hydroxy, --OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).sub.2,
--OC(O)R.sup.x or --OC(O)OR.sup.x; R.sup.2' is hydrogen, and
R.sup.2 is hydrogen, hydroxy,
--OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).sub.2 or --OC(O)OR.sup.x;
R.sup.3 is hydrogen, hydroxy, C.sub.1-6alkyloxy, --OC(O)R.sup.x,
--OCH.sub.2(OCH.sub.2).sub.mOP (O)(OH).sub.2 or --OC(O)OR.sup.x;
one of R.sup.6 or R.sup.7 is hydrogen and the other is hydroxy,
C.sub.1-6 alkanoyloxy, or
--OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH.sub.2); or R.sup.6 and R.sup.7
together form an oxo group; with the proviso that at least one of
R.sup.1, R.sup.2, R.sup.3, R.sup.6 or R.sup.7 is
--OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).sub.2; m is 0, 1 or 2;
R.sup.4, R.sup.5, R.sup.x and p are as previously defined; or a
pharmaceutically acceptable salt thereof.
7. A compound of claim 6 wherein R.sup.2' is hydrogen, and R.sup.2
is --OCH.sub.2OP(O)(OH).sub.2; or a pharmaceutically acceptable
salt thereof.
8. A compound of claim 7 wherein R.sup.1 is hydroxy, --OC(O)R.sup.x
or --OC(O)OR.sup.x; and R.sup.x is as previously defined.
9. A compound of claim 8 wherein R.sup.x is C.sub.1-6alkyl.
10. A compound of claim 8 wherein R.sup.3 is hydrogen, hydroxy or
acetoxy.
11. A compound of claim 8 wherein R.sup.4(O).sub.p is phenyl or
t-butoxy.
12. A compound of claim 8 wherein R.sup.5 is phenyl, 2-furyl or
2-thienyl.
13. A compound of claim 1 which is
2'-O-(ethoxycarbonyl)-7-O-(phosphonoxym- ethyl)paclitaxel, or a
pharmaceutically acceptable salt thereof.
14. The sodium salt of the compound of claim 13.
15. The triethanolamine salt of the compound of claim 13.
16. The triethylamine salt of the compound of claim 13.
17. The arginine salt of the compound of claim 13.
18. The lysin salt of the compound of claim 13.
19. The ethanolamine salt of the compound of claim 13.
20. The N-methylglucamine salt of the compound of claim 13.
21. A compound of claim 1 which is
7-O-(phosphonooxymethyl)paclitaxel, or a pharmaceutically
acceptable salt thereof.
22. The sodium salt of the compound of claim 21.
23. A compound of claim 1 which is
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-but-
yloxycarbonyl)-3'-(2-furyl)-2'-O-ethyloxycarbonyl-7-O-phosphonooxymethylpa-
clitaxel, or a pharmaceutically acceptable salt thereof.
24. The triethanolamine salt of the compound of claim 23.
25. A compound of claim 1 which is
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-but-
yloxycarbonyl)-3'-2-thienyl)-2'-O-ethyloxycarbonyl-7-O-phosphonooxymethypa-
clitaxel or a pharmaceutically acceptable salt thereof.
26. The triethanolamine salt of the compound of claim 25.
27. The compound of claim 1 which is
2'-O-methylcarbonyl-7-O-phosphonooxym- ethylpaclitaxel.
28. A compound of claim 1 which is
2'-O-methylcarbonyl-7-O-phosphonooxymet- hylpaclitaxel.
29. A compound of claim 1 which is
2'-O-n-propylcarbonyl-7-O-phosphonooxym- ethylpaclitaxel.
30. A compound of claim 6 wherein R.sup.1 is
--OCH.sub.2OP(O)(OH).sub.2, or a pharmaceutically acceptable salt
thereof.
31. A compound of claim 30 wherein R.sup.2' is hydrogen, R.sup.2 is
hydrogen, hydroxy or --OC(O)OR.sup.x, and R.sup.x is as defined as
claim 6.
32. A compound of claim 31 wherein R.sup.3 is hydrogen, hydroxy or
acetoxy.
33. A compound of claim 31 wherein R.sup.4(O).sub.p is phenyl or
t-butoxy.
34. A compound of claim 31 wherein R.sup.5 is phenyl.
35. A compound of claim 1 which is
2'-O-(phosphonooxymethyl)paclitaxel, or a pharmaceutically
acceptable salt thereof.
36. A compound of claim 6 wherein R.sup.1 and R.sup.2 are both
--OCH.sub.2OP(O)(OH).sub.2, or a pharmaceutically acceptable salt
thereof.
37. A compound of claim 1 which is
2',7-O-bis(phosphonooxymethyl)paclitaxe- l or a pharmaceutically
acceptable salt thereof.
38. The sodium salt of the compound of claim 37.
39. A compound of claim 6 wherein R.sup.1 is
--OCH.sub.2OCH.sub.2OP(O)(OH)- .sub.2, or a pharmaceutically
acceptable salt thereof.
40. A compound of claim 1 which is
2'-O-phosphonooxymethoxymethyl-7-O-phos-
phonooxymethylpaclitaxel.
41. A compound of claim 1 which is
2'-O-phosphonooxymethoxymethylpaclitaxe- l, or a pharmaceutically
acceptable salt thereof.
42. The triethanolamine salt of the compound of claim 41.
43. A compound of claim 6 wherein R.sup.3 is
--OCH.sub.2OP(O)(OH).sub.2, or a pharmaceutically acceptable salt
thereof.
44. A compound of claim 1 which is
10-desacetyl-3'-N-desbenzoyl-3'-N-(t-bu-
tyloxycarbonyl)-10-O-(phosphonooxymethyl)paclitaxel, or a
pharmaceutically acceptable salt thereof.
45. The triethanolamine salt of compound of claim 44.
46. A compound of claim 6 wherein R.sup.1 is
--OCH.sub.2OCH.sub.2OCH.sub.2- OP(O)(OH).sub.2.
47. A compound of claim 46 which is
2'-O-[(phosphonooxymethyl)methoxymethy- l]paclitaxel.
48. A compound of claim 46 which is
2'-O-[(phosphonooxymethyl)methoxy]meth-
yl-7-O-phosphooxypaclitaxel.
49. A compound having the formula
13--OH--txn--[OCH.sub.2(OCH.sub.2).sub.m- SCH.sub.3].sub.n wherein
txn is a taxane moiety, m and n are as previously defined, or a C13
metal alkoxide thereof.
50. A compound of claim 49 wherein said taxane moiety is derived
from a residue having the formula 119wherein R.sup.2e, R.sup.2e',
R.sup.3e, R.sup.6e and R.sup.7e are as previously defined.
51. A compound of claim 49 having the formula 120or a C13 metal
alkoxide thereof.
52. A compound having the formula
T'--[OCH.sub.2(OCH.sub.2).sub.mSCH.sub.3- ].sub.n wherein T' is T
in which non-reacting hydroxy groups have been blocked, m and n are
as defined above.
53. A compound of claim 52 having the formula 121wherein R.sup.1b
is hydroxy, protected hydroxy, --OCH.sub.2SCH.sub.3, --OC(O)R.sup.x
or --OC(O)OR.sup.x; R.sup.2 is hydrogen, and R.sup.2b is hydrogen,
hydroxy, protected hydroxy, --OCH.sub.2SCH.sub.3 or
--OC(O)OR.sup.x; R.sup.3b is hydrogen, hydroxy, protected hydroxy,
C.sub.1-6alkyloxy, --OC(O)R.sup.x, --OCH.sub.2SCH.sub.3 or
OC(O)OR.sup.x; one of R.sup.6b or R.sup.7b is hydrogen and the
other is hydroxy, protected hydroxy, C.sub.1-6 alkanoyloxy or
--OCH.sub.2SCH.sub.3; or R.sup.6b and R.sup.7b together form an oxo
group; with the proviso that at least on of R.sup.1b, R.sup.2b,
R.sup.3b, R.sup.6b or R.sup.7b is --OCH.sub.2SCH.sub.3; p, R.sup.4,
R.sup.5 and R.sup.x are as previously defined.
54. A compound of claim 53 that is
7-O-methylthiomethylpaclitaxel.
55. A compound of claim 53 that is
2'-O-(benzyloxycarbonyl)-7-O-methylthio- methylpaclitaxel.
56. A compound of claim 53 that is
2'-O-(ethoxycarbonyl)-7-O-methylpaclita- xel.
57. A compound of claim 53 that is
2'-O-(methylthiomethyl)-7-O-(triethylsi- lyl)paclitaxel.
58. A compound of claim 53 that is
2'-O-(methylthiomethyl)paclitaxel.
59. A compound of claim 53 that is
2',7-O-bis(methylthiomethyl)paclitaxel.
60. A compound of claim 53 that is
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-but-
yloxycarbonyl)-3'-(2-furyl)-7-O-methylthiomethylpaclitaxel.
61. A compound of claim 53 that
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butylo- xycarbonyl
-3'-(2-furyl)-2'-O-ethyloxycarbonyl-7-O-methylthiomethylpaclita-
xel.
62. A compound of claim 53 that is
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-but-
yloxycarbonyl)-3'-(2-thienyl)-7-O-methylthiomethylpaclitaxel.
63. A compound of claim 53 that is
3'-N-debenzoyl-3'-desphenyl-N-(t-butylo-
xycarbonyl)-3'-(2-thienyl)-2'-O-ethyloxycarbonyl-7-O-methylthiomethylpacli-
taxel.
64. A compound of claim 53 that is
3'-N-debenzoyl-3'-N-(isopropyloxycarbon-
yl)-7-O-methylthiomethylpaclitaxel.
65. A compound of claim 53 that is
3'-N-debenzoyl-3'-N-(n-butyloxycarbonyl-
-7-O-methylthiomethylpaclitaxel.
66. A compound of claim 53 that is
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)--
2'-O-triethylsilyl-7-O-methylthiomethylpaclitaxel.
67. A compound of claim 53 that is
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)--
7-O-methylthiomethylpaclitaxel.
68. A compound of claim 53 that is
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)--
7-O-methylthyliomethyl-10-deacetyl-10-hydroxymethylcarbonyl(paclitaxel).
69. A compound of claim 53 that is
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)--
7-O-methylthiomethyl-3'-desphenyl-3-isobutenylpaclitaxel.
70. A compound of claim 53 that is
3'-N-benzoyl-3'-N-(t-butoxycarbonyl)-2'-
-O-ethyloxycarbonyl-O-methylthiomethylpaclitaxel.
71. A compound of claim 53 that is
7-O-methylthiomethyl-3'-desphenyl-3'-is- obutenylpaclitaxel.
72. A compound of claim 53 that is
3'-desphenyl-3'-(2-furyl)-2'-O-ethyloxy-
carbonyl-7-O-methylthiomethylpaclitaxel.
73. A compound of claim 52 having the formula 122wherein R.sup.2',
R.sup.2b, R.sup.3b, R.sup.4, R.sup.5, R.sup.6b, R.sup.7b, and p are
as previously defined.
74. A compound of claim 73 that is
2'-O-(methylthiomethoxymethyl)-7-O-trie- thysilylpaclitaxel.
75. A compound of claim 73 that is
2'-O-(methylthiomethoxymethyl)-7-O-benz-
yloxycarbonylpaclitaxel.
76. A compound having the formula
T'--[OCH.sub.2(OCH.sub.2).sub.mOP(O)(OR.- sup.y).sub.2].sub.n
wherein T', m and n are as defined above, and R.sup.y is a
phosphono protecting group.
77. A compound of claim 76 having the formula 123wherein R.sup.1c
is hydroxy, protected hydroxy,
--OCH.sub.2OP(O)(OCH.sub.2R.sup.y).sub.2, --OC(O)R.sup.x or
--OC(O)OR.sup.x; R.sup.2' is hydrogen, R.sup.2c is hydrogen,
hydroxy, protected hydroxy, --OCH.sub.2OP(O)(OCH.sub.2R.sup.y).-
sub.2 or ; R.sup.3c is hydrogen, hydroxy, C.sub.1-6alkyloxy,
protected hydroxy, --OC(O)R.sup.x,
--OCH.sub.2OP(O)(OCH.sub.2R.sup.y).sub.2 or --OC(O)OR.sup.x; one of
R.sup.6c or R.sup.7c is hydrogen and the other is hydroxy,
protected hydroxy, C.sub.1-6 alkanoyloxy or
--OCH.sub.2OP(O)(OR.sup.y).sub.2; or R.sup.6c and R.sup.7c together
form an oxo group; with the proviso that at least one of R.sup.1c,
R.sup.2c, R.sup.3c, R.sup.6c or R.sup.7c
--OCH.sub.2OP(O)(OCH.sub.2R.sup.y).sub.2; p, R.sup.4, R.sup.5,
R.sup.x and R.sup.y are as previously defined.
78. A compound of claim 76 having the formula 124wherein R.sup.2',
R.sup.2c, R.sup.3c, R.sup.4, R.sup.5, R.sup.6c, R.sup.7c, R.sup.y
and p are as previously defined.
79. A pharmaceutical composition which comprises an antitumor
effective amount of a compound of claim 1 and a pharmaceutically
acceptable carrier.
80. A method for inhibiting tumor growth in a mammalian host which
comprises administering to said mammal a tumor-growth inhibiting
amount of a compound of claim 1.
81. A method for inhibiting tumor growth in a mammalian host which
comprises administering to said mammal by oral route a tumor-growth
inhibiting amount of a compound of claim 1.
82. A method for inhibiting tumor in a mammalian host which
comprises administering to said mammalian host an antitumor
effective amount of a compound of the formula (B'): 125wherein
R.sup.1b' is hydroxy, --OC(O)R.sup.x or --OC(O)OR.sup.x; R.sup.3b'
is hydrogen, hydroxy, --OC(O)OR.sup.x, C.sub.1-6alkyloxy or
--OC(O)R.sup.x; one of R.sup.6b' or R.sup.7b' is hydrogen and the
other is hydroxy or C.sub.1-6 alkanoyloxy; or R.sup.6b' and
R.sup.7b' together form an oxo group; and R.sup.4, R.sup.5, p and
R.sup.x are as previously defined; with the proviso that a compound
of formula cannot be 3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butylox-
ycarbonyl)-3'-(2-furyl)-7-O-methylthiomethylpaclitaxel or
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarbonyl)-3'-(2-furyl)-2'-O-e-
thyloxycarbonyl-7-O-methylthiomethylpaclitaxel.
83. A method as claimed in claim 82 for
7-O-methylthiomethylpaclitaxel.
84. A method as claimed in claim 82 for
2'-O-(benzyloxycarbonyl)-7-O-methy- lthiomethylpalitaxel.
85. A method as claimed in claim 82 for
2'-O-(ethoxycarbonyl)-7-O-methylth- iomethylpaclitaxel.
86. A method as claimed in claim 82 for
3'-N-debenzoyl-3'-desphenyl-3'-N-(-
t-butyloxycarbonyl)-(2-thienyl)-7-O-methylthiomethylpaclitaxel.
87. A method as claimed in claim 82 for
3'-N-debenzoyl-3'-desphenyl-3'-N-(-
t-butyloxycarbonyl)-3'-(2-thienyl)-2'-O-ethyloxycarbonyl-7-O-methylthiomet-
hylpaclitaxel.
88. A method as claimed in claim 82 for
3'-N-debenzoyl-3'-N-(isopropyloxyc-
arbonyl)-7-O-methylthiomethylpaclitaxel.
89. A method as claimed in claim 82 for
3'-N-debenzoyl-3'-N-(n-butyloxycar-
bonyl)-7-O-methylthiomethylpaclitaxel.
90. A method as claimed in claim 82 for
3'-N-debenzoyl-3'-N-(t-butoxycarbo-
nyl)-7-O-methylthiomethylpaclitaxel.
91. A method as claimed in claim 82 for
3'-N-debenzoyl-3'-N-(t-butoxycarbo-
nyl)-7-O-methylthiomethyl-10-deacetyl-10-hydroxymethylcarbonyl(paclitaxel)-
.
92. A method as claimed in claim 82 for
3'-N-debenzoyl-3'-N-(t-butyoxycarb-
onyl)-7-O-methylthiomethyl-3'-desphenyl-3'-isobutenylpaclitaxel.
93. A method as claimed in claim 82 for
3'-N-debenzoyl-3'-N-(t-butoxycarbo-
nyl)-2'-O-ethyloxycarbonyl-7-O-methylthiomethylpaclitaxel.
94. A method as claimed in claim 82 for
7-O-methylthiomethyl-3'-desphenyl--
3'-desphenyl-3'-isobutenylpaclitaxel.
95. A method as claimed in claim 82 for
3'-desphenyl-3'-(2-furyl)-2'-O-eth-
yloxycarbonyl-7-O-methylthiomethylpaclitaxel.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of our
application U.S. Ser. No. 08/154,840, filed Nov. 24, 1993, which is
a continuation-in-part of U.S. Ser. No. 08/108,015 filed Aug. 17,
1993, which in turn is a continuation-in-part of U.S. Ser. No.
07/996,455 filed Dec. 24, 1992, now abandoned. U.S. Ser. No.
08/154,840 is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention concerns antitumor compounds. More
particularly, the invention provides novel taxane derivatives,
pharmaceutical compositions thereof, and their use as antitumor
agents.
[0004] 2. Background Art
[0005] Taxol.RTM. (paclitaxel) is a natural product extracted from
the bark of Pacific yew trees, Taxus brevifolia. It has been shown
to have excellent antitumor activity in in vivo animal models, and
recent studies have elucidated its unique mode of action, which
involves abnormal polymerization of tubulin and disruption of
mitosis. It was recently approved for the treatment of ovarian
cancer; and studies involving breast, colon, and lung cancers have
shown promising results. The results of paclitaxel clinical studies
are reviewed in Rowinsky and Donehower, "The Clinical Pharmacology
and Use of Antimicrotubule Agents in Cancer Chemotherapeutics"
Pharmac. Ther., 52:35-84, 1991.
[0006] Recently, a semi-synthetic analog of paclitaxel named
Taxotere.RTM. has also been found to have good antitumor activity
in animal models. Taxotere.RTM. is also currently undergoing
clinical trials in Europe and the United States. The structures of
paclitaxel and Taxotere.RTM. are shown below; the conventional
numbering system of the paclitaxel molecule is provided. 1
[0007] One drawback of paclitaxel is its very limited water
solubility requiring it to be formulated in nonaqueous
pharmaceutical vehicles. One commonly used carrier is Cremophor EL
which may itself have undesirable side effects in man. Accordingly,
a number of research teams have prepared water-soluble derivatives
of paclitaxel which are disclosed in the following references:
[0008] (a) Haugwitz et al, U.S. Pat. No. 4,942,184;
[0009] (b) Kingston et al, U.S. Pat. No. 5,059,699;
[0010] (c) Stella et al, U.S. Pat. No. 4,960,790;
[0011] (d) European Patent Application 0,558,959 A1 published Sep.
8, 1993;
[0012] (e) Vyas et al, Bioorganic & Medicinal Chemistry
Letters, 1993, 3:1357-1360; and
[0013] (f) Nicolaou et al, Nature, 1993, 364:464-466
[0014] Compounds of the present invention are phosphonooxymethyl
ethers of taxane derivatives and pharmaceutically acceptable salts
thereof. The water solubility of the salts facilitates preparation
of pharmaceutical formulations.
SUMMARY OF THE INVENTION
[0015] The present invention relates to taxane derivatives having
the formula (A):
T--[OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).sub.2].sub.n (A)
[0016] wherein T is a taxane moiety bearing on the C13 carbon atom
a substituted 3-amino-2-hydroxypropanoyloxy group; n is 1, 2 or 3;
m is 0 or an integer from 1 to 6 inclusive; or a pharmaceutically
acceptable salt thereof.
[0017] Another aspect of the present invention provides taxane
derivatives having the formula (B):
T'--[OCH.sub.2(OCH.sub.2).sub.mSCH.sub.3].sub.n (B)
[0018] wherein T' is T in which non-reacting hydroxy groups have
been blocked, m and n are as defined under formula (A).
[0019] Yet another aspect of the present invention provides
intermediates having the formula (C):
T'--[OCH.sub.2(OCH.sub.2).sub.mOP(O)(OR.sup.y).sub.2].sub.n (C)
[0020] wherein T', m and n are as defined under formula (A), and
R.sup.y is a phosphono protecting group.
[0021] Another aspect of the present invention provides compounds
of the formula (D):
13--OH--txn--[OCH.sub.2(OCH.sub.2).sub.mSCH.sub.3].sub.n (D)
[0022] wherein m and n are as defined above; and txn is a taxane
moiety; or a C13 metal alkoxide thereof.
[0023] Another aspect of the present invention provides a method
for inhibiting tumor in a mammalian host which comprises
administering to said mammalian host an antitumor effective amount
of a compound of formula (A).
[0024] Further aspect of the present invention provides a method
for inhibiting tumor in a mammalian host which comprises
administering to said mammalian host an antitumor effective amount
of a compound of the formula (B'): 2
[0025] wherein R.sup.1b' is hydroxy, --OC(O)R.sup.x or
--OC(O)OR.sup.x; R.sup.3b' is hydrogen, hydroxy, --OC(O)OR.sup.x,
C.sub.1-6alkyloxy or --OC(O)R.sup.x; one of R.sup.6b' or R.sup.7b'
is hydrogen and the other is hydroxy or C.sub.1-6 alkanoyloxy; or
R.sup.6b' and R.sup.7b' together form an oxo group; R.sup.4 and
R.sup.5 are independently C.sub.1-6 alkyl, C.sub.2-6 alkenyl,
C.sub.2-6 alkynyl, or --Z--R.sup.6; Z is a direct bond, C.sub.1-6
alkyl or C.sub.2-6 alkenyl; R.sup.6 is aryl, substituted aryl,
C.sub.3-6 cycloalkyl or heteroaryl; p is 0 or 1; R.sup.x is
C.sub.1-6 alkyl optionally, substituted with one to six same or
different halogen atoms, C.sub.3-6 cycloalkyl, C.sub.2-6 alkenyl or
hydroxy; or R.sup.x is a radical of the formula 3
[0026] wherein D is a bond or C.sub.1-6 alkyl; and R.sup.a, R.sup.b
and R.sup.c are independently hydrogen, amino, C.sub.1-6
alkylamino, di-C.sub.1-6alkylamino, halogen, C.sub.1-6 alkyl, or
C.sub.1-6 alkoxy.
[0027] Thus, another aspect of the present invention provides a
pharmaceutical composition which comprises an antitumor effective
amount of a compound of formula (B') or (A) and a pharmaceutically
acceptable carrier.
DETAILED DESCRIPTION OF THE INVENTION
[0028] In the application, unless otherwise specified explicitly or
in context, the following definitions apply. "Alkyl" means a
straight or branched saturated carbon chain having from one to six
carbon atoms; examples include methyl, ethyl, n-propyl, isopropyl,
n-butyl, sec-butyl, isobutyl, t-butyl, n-pentyl, sec-pentyl,
isopentyl, and n-hexyl. "Alkenyl" means a straight or branched
carbon chain having at least one carbon-carbon double bond, and
having from two to six carbon atoms; examples include ethenyl,
propenyl, isopropenyl, butenyl, isobutenyl, pentenyl, and hexenyl.
"Alkynyl" means a straight or branched carbon chain having at least
one carbon-carbon triple bond, and from two to six carbon atoms;
examples include ethynyl, propynyl, butynyl, and hexynyl.
[0029] "Aryl" means aromatic hydrocarbon having from six to ten
carbon atoms; examples include phenyl and naphthyl. "Substituted
aryl" means aryl substituted with at least one group selected from
C.sub.1-6 alkanoyloxy, hydroxy, halogen, C.sub.1-6 alkyl,
trifluoromethyl, C.sub.1-6 alkoxy, aryl, C.sub.2-6 alkenyl,
C.sub.1-6 alkanoyl, nitro, amino, and amido. "Halogen" means
fluorine, chlorine, bromine, and iodine.
[0030] "Phosphono-" means the group --P(O) (OH).sub.2 and
"phosphonooxymethoxy" or "phosphonooxymethyl ether" means
generically the group --OCH.sub.2(OCH.sub.2).sub.mOP(O) (OH).sub.2.
"(Methylthio)thiocarbonyl" means the group --C(S)SCH.sub.3.
"Methylthiomethyl" (also abbreviated as MTM) generically refers to
the group --CH.sub.2SCH.sub.3.
[0031] "Taxane moiety" (also abbreviated as txn) denotes moieties
containing the twenty carbon taxane core framework represented by
the structural formula shown below with the absolute configuration.
4
[0032] The numbering system shown above is one used in conventional
taxane nomenclature, and is followed throughout the application.
For example, the notation C1 refers to the carbon atom labelled as
"1"; C5-C20 oxetane refers to an oxetane ring formed by the carbon
atoms labelled as 4, 5 and 20 with an oxygen atom; and C9 oxy
refers to an oxygen atom attached to the carbon atom labelled as
"9", said oxygen atom may be an oxo group, .alpha.- or
.beta.-hydroxy, or .alpha.- or .beta.-acyloxy.
[0033] "Substituted 3-amino-2-hydroxypropanoyloxy" denotes a
residue represented by the formula 5
[0034] (X is a nonhydrogen group and X' is hydrogen or a
non-hydrogen group.) The stereochemistry of this residue is the
same as the paclitaxel sidechain. This group is sometimes referred
to in the application as the "C13 sidechain."
[0035] "Taxane derivative" (abbreviated as T) refers to a compound
having a taxane moiety bearing a C13 sidechain.
[0036] "Heteroaryl" means a five- or six-membered aromatic ring
containing at least one and up to four non-carbon atoms selected
from oxygen, sulfur and nitrogen. Examples of heteroaryl include
thienyl, furyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl,
isothiazolyl, oxazolyl, isoxazolyl, triazolyl, thiadiazolyl,
oxadiazolyl, tetrazolyl, thiatriazolyl, oxatriazolyl, pyridyl,
pyrimidyl, pyrazinyl, pyridazinyl, triazinyl, tetrazinyl, and like
rings.
[0037] "Phosphono protecting groups" means moieties which can be
employed to block or protect the phosphono functional group;
preferably such protecting groups are those that can be removed by
methods that do not appreciably affect the rest of the molecule.
Suitable phosphonooxy protecting groups are well known to those
skilled in the art and include for example benzyl and allyl
groups.
[0038] "Hydroxy protecting groups" include, but is not limited to,
ethers such as methyl, t-butyl, benzyl, p-methoxybenzyl,
p-nitrobenzyl, allyl, trityl, methoxymethyl, methoxyethoxymethyl,
ethoxyethyl, tetrahydropyranyl, tetrahydrothiopyranyl, and
trialkylsilyl ethers such as trimethylsilyl ether, triethylsilyl
ether, and t-butyldimethylsilyl ether; esters such as benzoyl,
acetyl, phenylacetyl, formyl, mono-, di-, and trihaloacetyl such as
chloroacetyl, dichloroacetyl, trichloroacetyl, trifluoroacetyl; and
carbonates such as methyl, ethyl, 2,2,2-trichloroethyl, allyl,
benzyl, and p-nitrophenyl.
[0039] Additional examples of hydroxy and phosphono protecting
groups may be found in standard reference works such as Greene and
Wuts, Protective Groups in Organic Synthesis, 2d Ed., 1991, John
Wiley & Sons, and McOmie, Protective Groups in Organic
Chemistry, 1975, Plenum Press. Methods for introducing and removing
protecting groups are also found in such textbooks.
[0040] "Pharmaceutically acceptable salt" means a metal or an amine
salt of the acidic phosphono group in which the cation does not
contribute significantly to the toxicity or biological activity of
the active compound. Suitable metal salts include lithium, sodium,
potassium, calcium, barium, magnesium, zinc, and aluminum salts.
Preferred metal salts are sodium and potassium salts. Suitable
amine salts are for example, ammonia, tromethamine (TRIS),
triethylamine, procaine, benzathine, dibenzylamine, chloroprocaine,
choline, diethanolamine, triethanolamine, ethylenediamine,
glucamine, N-methylglucamine, lysine, arginine, ethanolamine, to
name but a few. Preferred amine salts are lysine, arginine,
triethanolamine, and N-methylglucamine salts. Even more preferred
salt is N-methylglucamine or triethanolamine.
[0041] As used herein, the term
--OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).sub.- 2 is intended to
emcompass both the free acid and its pharmaceutically acceptable
salts, unless the context indicates specifically that the free acid
is meant.
[0042] One aspect of the present invention provides taxane
derivatives of the formula (A)
T--[OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).sub.2].sub.n (A)
[0043] wherein T is a taxane moiety bearing on the C13 carbon atom
a substituted 3-amino-2-hydroxypropanoyloxy group; n is an 1, 2 or
3; m is 0, or an integer from 1 to 6 inclusive, or a
pharmaceutically acceptable salt thereof.
[0044] Another aspect of the present invention provides taxane
derivatives having the formula (B)
T'--[OCH.sub.2(OCH.sub.2).sub.mSCH.sub.3].sub.n (B)
[0045] which are useful in making taxane derivatives of the formula
(A).
[0046] In one embodiment the taxane moiety contains at least the
following functionalities: C1-hydroxy, C2-benzoyloxy, C4-acetyloxy,
C5-C20 oxetane, C9-oxy, and C11-C12 double bond.
[0047] In a preferred embodiment the taxane moiety is derived from
a residue having the formula 6
[0048] wherein R.sup.2e' is hydrogen and R.sup.2e is hydrogen,
hydroxy, --OC(O)R.sup.x, or --OC(O)OR.sup.x; or R.sup.2e is
hydrogen and R.sup.2e' is fluoro; R.sup.3e is hydrogen, hydroxy,
--OC(O)R.sup.x, --OC(O)OR.sup.x or C.sub.1-6alkyloxy; one of
R.sup.6e or R.sup.7e is hydrogen and the other is hydroxy or
--OC(O)R.sup.x; or R.sup.6e and R.sup.7e together form an oxo
group; R.sup.x is as defined below.
[0049] In another embodiment, the C13 sidechain is derived from a
residue having the formula 7
[0050] wherein R.sup.1e is hydrogen or --C(O)R.sup.x,
--C(O)OR.sup.x; R.sup.4 and R.sup.5 are independently C.sub.1-6
alkyl, C.sub.2-6 alkenyl, C.sub.2-6 alkynyl, or --Z--R.sup.6; Z is
a direct bond, C.sub.1-6 alkyl or C.sub.2-6 alkenyl; R.sup.6 is
aryl, substituted aryl, C.sub.3-6 cycloalkyl, or heteroaryl; and
R.sup.x is C.sub.1-6 alkyl optionally substituted with one to six
same or different halogen atoms, C.sub.3-6 cycloalkyl, C.sub.2-6
alkenyl or hydroxy; or R.sup.x is a radical of the formula 8
[0051] wherein D is a bond or C.sub.1-6 alkyl; and R.sup.a, R.sup.b
and R.sup.c are independently hydrogen, amino, C.sub.1-6
alkylamino, di-C.sub.1-6alkylamino, halogen, C.sub.1-6 alkyl, or
C.sub.1-6 alkoxy; p is 0 or 1.
[0052] In a preferred embodiment, R.sup.4 is C.sub.1-6 alkyl and p
is 1, or R.sup.4 is or --Z--R.sup.6 and p is 0. More preferably,
R.sup.4(O).sub.p is t-butoxy, phenyl, isopropyloxy, n-propyloxy, or
n-butoxy.
[0053] In another preferred embodiment R.sup.5 is C.sub.2-6alkenyl
or --Z--R.sup.6 and Z and R.sup.6 are as previously defined. More
preferably, R.sup.5 is phenyl, 2-furyl, 2-thienyl, isobutenyl,
2-propenyl, or C.sub.3-6cycloalkyl.
[0054] In another embodiment, compound of formula (A) may be more
specifically represented by the formula (I) 9
[0055] wherein R.sup.1 is hydroxy,
--OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).s- ub.2, --OC(O)R.sup.x or
--OC(O)OR.sup.x; R.sup.2 is hydrogen, and R.sup.2 is hydrogen,
hydroxy, --OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).sub.2 or
--OC(O)OR.sup.x; or R.sup.2' is fluoro, and R.sup.2 is hydrogen;
R.sup.3 is hydrogen, hydroxy, C.sub.1-6alkyloxy, --OC(O)R.sup.x,
--OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).sub.2 or --OC(O)OR.sup.x; one
of R.sup.6 or R.sup.7 is hydrogen and the other is hydroxy,
C.sub.1-6 alkanoyloxy, or
--OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).sub.2; or R.sup.6 and R.sup.7
together form an oxo group; with the proviso that at least one of
R.sup.1, R.sup.2, R.sup.3, R.sup.6 or R.sup.7 is
--OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).sub.2; R.sup.4, R.sup.5,
R.sup.x, m and p are as previously defined; or a pharmaceutically
acceptable salt thereof.
[0056] In compounds of formula (I), examples of R.sup.x include
methyl, hydroxymethyl, ethyl, n-propyl, isopropyl, n-butyl,
isobutyl, chloromethyl, 2,2,2-trichloroethyl, cyclopropyl,
cyclobutyl, cyclopentyl, cyclohexyl, ethenyl, 2-propenyl, phenyl,
benzyl, bromophenyl, 4-aminophenyl, 4-methylaminophenyl,
4-methylphenyl, 4-methoxyphenyl and the like. Examples of R.sup.4
and R.sup.5 include 2-propenyl, isobutenyl, 3-furanyl (3-furyl),
3-thienyl, phenyl, naphthyl, 4-hydroxyphenyl, 4-methoxyphenyl,
4-fluorophenyl, 4-trifluoromethylphenyl, methyl, ethyl, n-propyl,
isopropyl, n-butyl, isobutyl, t-butyl, ethenyl, 2-propenyl,
2-propynyl, benzyl, phenethyl, phenylethenyl, 3,4-dimethoxyphenyl,
2-furanyl (2-furyl), 2-thienyl, 2-(2-furanyl)ethenyl,
2-methylpropyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,
cyclohexylmethyl, cyclohexylethyl and the like.
[0057] In one embodiment, the present invention provides a
preferred group of compounds of formula (I) in which R.sup.5 is
C.sub.2-6alkenyl or --Z--R.sup.6 and Z and R.sup.6 are as
previously defined. More preferably, R.sup.5 is phenyl, 3-furyl,
3-thienyl, 2-propenyl, isobutenyl, 2-furyl, 2-thienyl, or
C.sub.3-6cycloalkyl.
[0058] In another preferred embodiment R.sup.4 of compounds of
formula (I) is C.sub.1-6alkyl in which case p is 1; or R.sup.4 is
--Z--R.sup.6 and Z and R.sup.6 are as previously defined, and in
which case p is 0. More preferably R.sup.4(O).sub.p-- is t-butoxy,
phenyl, isopropyloxy, n-propyloxy, n-butoxy.
[0059] In another preferred embodiment, the present invention
provides compounds of formula (I) in which R.sup.1 is
--OCH.sub.2(OCH.sub.2).sub.m- OP(O)(OH).sub.2. In a more preferred
embodiment, R.sup.2 is hydroxy,
--OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).sub.2, or --OC(O)R.sup.x, and
R.sup.x is preferably C.sub.1-6 alkyl. In another more preferred
embodiment, R.sup.3 is hydroxy or acetoxy.
[0060] In another preferred embodiment, the present invention
provides compound of formula (I) in which R.sup.2 is
--OCH.sub.2(OCH.sub.2).sub.mO- P(O)(OH).sub.2; R.sup.1 is hydroxy
or --OC(O)OR.sup.x; and R.sup.3 is hydrogen, hydroxy, acetoxy,
--OCH.sub.2(OCH.sub.2).sub.mOP(O)(OH).sub.2 or --OC(O)OR.sup.x; and
R.sup.x is as previously defined. In a more preferred embodiment
R.sup.1 is hydroxy or --OC(O)OR.sup.x and R.sup.x is preferably
C.sub.1-6 alkyl; and R.sup.3 is hydroxy or acetoxy.
[0061] In another preferred embodiment, the present invention
provides compound of formula (I) in which R.sup.3 is
--OCH.sub.2(OCH.sub.2).sub.mO- P(O)(OH).sub.2; R.sup.1 is hydroxy
or --OC(O)OR.sup.x; R.sup.2' is hydrogen, and R.sup.2 is hydrogen,
hydroxy or --OC(O)OR.sup.x; or R.sup.2' is fluoro and R.sup.2 is
hydrogen; and R.sup.x is as previously defined. In a more preferred
embodiment, R.sup.1 is hydroxy or --OC(O)OR.sup.x, and R.sup.x is
preferably C.sub.1-6 alkyl. In another more preferred embodiment,
R.sup.2 is hydroxy.
[0062] In another preferred embodiment, m is 0 or 1 when the
phosphonooxymethoxy group is present on the C7 of the taxane
moiety.
[0063] The preferred pharmaceutically acceptable salts of a
compound of formula (A) are alkali metal salts including lithium,
sodium and potassium salts; and amine salts including
triethylamine, triethanolamine, ethanolamine, arginine, lysine and
N-methylglucamine salts. Even more preferred salts are sodium,
triethanolamine, and N-methylglucamine salts.
[0064] The most preferred embodiments of taxane derivatives of
formula (A) include the following compounds: (1)
7-O-phosphonooxymethylpaclitaxel, (2)
2'-O-(ethyloxycarbonyl)-7-O-phosphonooxymethylpaclitaxel; (3)
2'-O-phosphonooxymethylpaclitaxel; (4)
2',7-bis-O-(phosphonooxymethyl)pac- litaxel; (5)
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarbonyl)-3'-(2-f-
uryl)-2'-O-ethyloxycarbonyl-7-O-phosphonooxymethylpaclitaxel; (6)
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarbonyl)-3'-(2'-thienyl)-2-O-
-ethyloxycarbonyl-7-O-phosphonooxymethylpaclitaxel; (7)
10-desacetyl-3'-N-desbenzoyl-3'-N-(t-butyloxycarbonyl)-10-O-(phosphonooxy-
methyl)paclitaxel; (8) 2'-O-phosphonooxymethoxymethylpaclitaxel;
(9) 2'-O-n-propylcarbonyl-7-O-phosphonooxymethylpaclitaxel; (10)
2'-O-methylcarbonyl-7-O-phosphonooxymethylpaclitaxel; (11)
2'-O-methoxycarbonyl-7-O-phosphonooxymethylpaclitaxel; (12)
2'-O-phosphonooxymethoxymethyl-7-O-phosphonooxymethylpaclitaxel;
and their respective pharmaceutically acceptable salts,
particularly the sodium, potassium, arginine, lysine,
N-methylglucamine, ethanolamine, triethylamine and triethanolamine
salts.
[0065] Compounds of formula (A) may be prepared from a taxane
derivative starting material T-[OH].sub.n wherein T and n are as
previously defined. The identity of T-[OH].sub.n is not
particularly limited so long as there is at least one reactive
hydroxy group present on either the taxane moiety or the C13 side
chain to allow the formation of phosphonooxymethyl ether linkage.
It is to be understood that the reactive hydroxy group may be
directly attached to the C13 propanoyloxy backbone (e.g. the
2'-hydroxy group of paclitaxel) or to the taxane core framework
(e.g. the 7-hydroxy group of paclitaxel); or it may be present on a
substituent on the C13 sidechain, or on a substituent on the taxane
core. The reaction sequence shown in Scheme I may be used to
prepare compounds of formula (A) 10
[0066] In Scheme I T' is a taxane derivative in which non-reacting
hydroxy groups have been blocked; R.sup.y is a phosphono protecting
group; n and m are as previously defined. Thus an appropriately
protected T' having one or more reactive hydroxy groups is first
converted to a corresponding methylthiomethyl ether of formula (B).
Using paclitaxel as an example, T' may be paclitaxel itself (to
effect 2',7-bismethylthiomethylation), 7-O-triethylsilylpaclitaxel,
7-O-benzyloxycarbonylpaclitaxel, or 2'-O-ethoxycarbonylpaclitaxel.
A compound of formula (B) where m is 0 may be prepared by treating
T'-[OH].sub.n with dimethylsulfoxide/acetic anhydride, or with
dimethylsulfide and an organic peroxide. These reactions are
discussed more fully in a subsequent section.
[0067] The MTM ether having one intervening methyleneoxy unit (i.e.
compounds of formula (B) where m=1) may be prepared by several
possible routes. In one a compound of formula (B) where m=0 is
reacted with N-iodosuccinimide (NIS) and methylthiomethanol to
extend the chain by one methyleneoxy unit. 11
[0068] An analogous reaction of an alcohol with methylthiomethyloxy
group in the presence of NIS was reported by Veeneman et al, in
Tetrahedron, 1991, v47, pp. 1547-1562, the relevant portions
thereof are hereby incorporated by reference. Silver triflate is
preferably used as a catalyst.
[0069] The compound of methylthiomethanol and its preparation is
reported in Syn. Comm., 1986, 16 (13): 1607-1610.
[0070] In an alternative method, the T-alkoxide (Ad) generated by
treating a compound of formula (Aa) with a base such as n-butyl
lithium, lithium diisopropylamide or lithium hexamethyldisilazide,
is reacted with chloromethyl methylthiomethyl ether to provide a
compound of formula (B) in which m=1. 12
[0071] Compound (Ae) is prepared by reacting methylthiomethoxide
(obtained from methythiomethanol by treatment with a base such as
n-butyl lithium, lithium diisopropylamide or lithium
hexamethyldisilazide) with chloroiodomethane. Compound (Ae) may
also be prepared by treating 1,1'-dichlorodimethylether
(ClCH.sub.2OCH.sub.2Cl) with a stoichiometric amount or less (e.g.
about 0.8 equivalent) of sodium iodide followed by sodium
thiomethoxide. 1,1'-Dichlorodimethyl ether is reported in Ind. J.
Chem., 1989, 28B, pp. 454-456.
[0072] In another method, a compound of formula (Aa) is reacted
with bis(MTM)ether, CH.sub.3SCH.sub.2OCH.sub.2SCH.sub.3, and NIS to
give a compound of formula (B) in which m=1.
T'--[OH].sub.n+n
CH.sub.3SCH.sub.2OCH.sub.2SCH.sub.3.fwdarw.T'--[OCH.sub.2-
OCH.sub.2SCH.sub.3].sub.n
[0073] Bis(MTM)ether is prepared by reacting 1,1'-dichlorodimethyl
ether with sodium iodide followed by sodium thiomethoxide.
[0074] The procedure described above using methylthiomethanol and
NIS may be applied to any reagent having an MTM group to extend the
chain by one methyleneoxy unit at a time. For example, a compound
of formula (B) wherein m=1 can be reacted with methythiomethanol
and NIS to provide a compound of formula (B) wherein m=2. The
process may be repeated to provide compounds of formula (B) in
which m is 3, 4, 5 or 6.
[0075] In the second step shown in Scheme I, the methylthiomethyl
ether is converted to the corresponding protected
phosphonooxymethyl ether. This is accomplished by treating the MTM
ether with NIS and protected phosphate HOP(O)(OR.sup.y).sub.2. In
the third step, the phosphono protecting group and any hydroxy
protecting group(s) are removed to provide a compound of formula
(A). For example, a suitable phosphono protecting group is benzyl
which may be removed by catalytic hydrogenolysis; hydroxy
protecting groups such as trialkysilyl may be removed by fluoride
ion, trichloroethoxycarbonyl may be removed by zinc. Removal of
protecting groups are taught in textbooks such as Green and Wuts,
Protective Groups in Organic Synthesis, John Wiley & Sons,
1991; and McOmie, Protective in Organic Chemistry, Plenum Press,
1973. Both steps are discussed in detail in a later section in the
specification.
[0076] A variation of the reaction sequence shown in Scheme I is
provided in Scheme II. 13
[0077] In Scheme II, a compound of formula (Aa) is reacted with a
compound of formula (Ca) and NIS to give a compound of formula (C),
which is then deblocked to give a compound of formula (A).
Compounds of formula (Ca) in which m is 0 may be prepared by first
treating methylthiomethanol with a base such as Na, Li or K
hexamethyldisilazide to give methylthiomethoxide; the methoxide is
then reacted with a protected chlorophosphate such as dibenzyl
chlorophosphate to provide the desired-compound. Compounds of
formula (Ca) in which m is 1 may be prepared by treating
CH.sub.3SCH.sub.2OCH.sub.2Cl with a diprotected phosphate salt,
e.g. sodium, potassium, tetra(n-butyl)ammonium salts of dibenzyl
phosphate; or CH.sub.3SCH.sub.2OCH.sub.2Cl may be first converted
to the corresponding iodo compound using sodium iodide prior to
reacting with the phosphate salt. Alternatively, compounds of
formula (Ca) in which m is 1 may be prepared by, treating
ClCH.sub.2OCH.sub.2Cl with sodium iodide followed by sodium
thiomethoxide to provide CH.sub.3SCH.sub.2OCH.sub.2SCH.sub.3; this
compound is then treated with NIS and a diprotected phosphate such
as dibenzyl phosphate to give the desired product. Any of the
previously mentioned reagents having a MTM group may be extended
one methyleneoxy unit at a time by reacting said reagent with
methylthiomethanol and NIS.
[0078] In another method for preparing a compound of formula (A),
T-alkoxide (Ad) is reacted with an iodophosphate as shown in Scheme
III. 14
[0079] In Scheme III, the iodophosphate compound is obtained by
reacting ClCH.sub.2(OCH.sub.2).sub.mCl with a diprotected phosphate
salt to give ClCH.sub.2(OCH.sub.2).sub.mOP(O)(OR.sup.y).sub.2 which
is then treated with sodium iodide to give the desired product.
[0080] Yet another method suitable for preparing a subset of
compounds of formula (A) in which at least one of the
phosphonooxymethoxy groups is linked to the taxane moiety is shown
in Scheme IV. 15
[0081] In Scheme IV, m and n are as previously defined; X is a
non-hydrogen group, P is a hydroxy protecting group; txn is a
taxane moiety. Compounds of formula (D) are taxanes having a
13.alpha.-hydroxy group and one or more methylthiomethyl ether
linked directly or indirectly to the taxane core; also included are
C13 metal alkoxides of formula (D). An example of a compound of
formula (D) is 7-O-methylthiomethylbaccatin III: 16
[0082] The coupling of the taxane (D) with the azetidinone is
analogous to the one shown in Scheme VI, infra; thus the procedure
described there for the preparation of a compound of formula (Id)
is also applicable to the preparation of a compound of formula (Ba)
[i.e. a compound of formula (B) in which at least one of the MTM
group is linked directly or indirectly to the taxane moiety], if a
compound of formula (D) is used in place of a compound of formula
(II) in Scheme VI. The taxane (D) is preferably first converted to
a C13 metal alkoxide such as sodium, potassium or lithium alkoxide;
lithium alkoxide is preferred. The azetidinone serves as the
precursor of the C13 sidechain. After the coupling reaction with a
taxane, the hydroxy protecting group P is removed, and if desired,
the free hydroxy group on the sidechain may be converted to the MTM
ether or derivatized to an ester or a carbonate as herein
described.
[0083] The azetidinone may be prepared by methods described later
which are also methods generally known in the art. Compounds of
formula (D) may be prepared by the general procedure described
above for the preparation of compounds of formula (B) using a
suitably protected taxane. However, more conveniently, they can be
obtained from a compound of formula (Ba) by cleaving the
13-sidechain using a borohydride such as sodium or
tetrabutylammonium borohydride; for example, 7-O-MTM of paclitaxel
is treated with tetrabutylammonium borohydride to give 7-O-MTM
baccatin III.
[0084] The general process of Scheme I for the preparation of a
compound of formula (A) is more particularly exemplified in Scheme
V which illustrates the preparation of a compound of formula (I')
(i.e. a compound of formula (I) in which m is 0). The procedure
employed in this synthetic sequence is generally applicable to
other taxane derivatives not specifically encompassed by formula
(I). Furthermore, the procedure in Scheme (V) may be modified in
accordance with teachings contained herein by one skilled in the
art to arrive at taxane derivatives of formula (A) in which m is 1,
2 or 3.
[0085] It is to be understood that in Scheme V as well as elsewhere
in the specification, the term "hydroxy protecting group" may
encompass suitable carbonates (e.g. --OC(O)OR.sup.x in which
R.sup.x does not contain hydroxy); thus, when a carbonate is used
as a hydroxy protecting group, it is intended to be removed in a
later step to generate the free hydroxy group, otherwise, the
carbonate moiety remains as part of the final product. 17
[0086] In Scheme V, R.sup.1a is hydroxy, protected hydroxy,
--OC(O)R.sup.x or --OC(O)OR.sup.x ; R.sup.2 is hydrogen, and
R.sup.2a is hydrogen, hydroxy, protected hydroxy or
--OC(O)OR.sup.x; or R.sup.2' is fluoro, and R.sup.2a is hydrogen;
R.sup.3a is hydrogen, hydroxy, protected hydroxy,
C.sub.1-6alkyloxy, --OC(O)R.sup.x or --OC(O)OR.sup.x; one of
R.sup.6a or R.sup.7a is hydrogen and the other is hydroxy,
protected hydroxy or C.sub.1-6 alkanoyloxy; or R.sup.6a and
R.sup.7a together form an oxo group; with the proviso that at least
one of R.sup.1a, R.sup.2a or R.sup.3a, R.sup.6a or R.sup.7a is
hydroxy. R.sup.1b is hydroxy, protected hydroxy,
--OCH.sub.2SCH.sub.3, --OC(O)R.sup.x or --OC(O)OR.sup.x; R.sup.2'
is hydrogen, and R.sup.2b is hydrogen, hydroxy, protected hydroxy,
--OCH.sub.2SCH.sub.3 or --OC(O)OR.sup.x; or R.sup.2' is fluoro, and
R.sup.2b is hydrogen; R.sup.3b is hydrogen, hydroxy, protected
hydroxy, C.sub.1-6alkyloxy, --OC(O)R.sup.x, --OCH.sub.2SCH.sub.3 or
--OC(O)OR.sup.x; one of R.sup.6b or R.sup.7b is hydrogen and the
other is hydroxy, protected hydroxy, C.sub.1-6 alkanoyloxy or
--OCH.sub.2SCH.sub.3; or R.sup.6b and R.sup.7b together form an oxo
group; with the proviso that at least one of R.sup.1b, R.sup.2b,
R.sup.3b, R.sup.6b or R.sup.7b is --OCH.sub.2SCH.sub.3. R.sup.1c is
hydroxy, protected hydroxy, --OCH.sub.2OP(O)(OR.sup.y).sub.2,
--OC(O)R.sup.x or --OC(O)OR.sup.x; R.sup.2 is hydrogen, and
R.sup.2c is hydrogen, hydroxy, protected hydroxy,
--OCH.sub.2OP(O)(OR.sup.y).sub.2 or --OC(O)OR.sup.x; or R.sup.2 is
fluoro, and R.sup.2c is hydrogen; R.sup.3c is hydrogen, hydroxy,
protected hydroxy, C.sub.1-6alkyloxy, --OC(O)R.sup.x,
--OCH.sub.2OP(O)(OR.sup.y).sub.2 or --OC(O)OR.sup.x; one of
R.sup.6c or R.sup.7c is hydrogen and the other is hydroxy,
protected hydroxy, C.sub.1-6 alkanoyloxy or
--OCH.sub.2OP(O)(OR.sup.y).sub.2; with the proviso that at least
one of R.sup.1c, R.sup.2c, R.sup.3c, R.sup.6c or R.sup.7c is
--OCH.sub.2OP(O)(OR.sup.y).sub.2. R.sup.1' is hydroxy,
--OCH.sub.2OP(O)(OH).sub.2, --OC(O)R.sup.x or --OC(O)OR.sup.x;
R.sup.2"' is hydrogen, and R.sup.2" is hydrogen, hydroxy,
--OCH.sub.2OP(O)(OH).sub.- 2 or --OC(O)OR.sup.x; or R.sup.2'" is
fluoro, and R.sup.2" is hydrogen; R.sup.3' is hydrogen, hydroxy,
C.sub.1-6alkyloxy, --OC(O)R.sup.x, --OCH.sub.2OP(O)(OH).sub.2 or
--OC(O)OR.sup.x; one of R.sup.6' or R.sup.7' is hydrogen and the
other is hydroxy, C.sub.1-6 alkanoyloxy or
--OCH.sub.2OP(O)(OH).sub.2; with the proviso that at least one of
R.sup.1', R.sup.2', R.sup.3', R.sup.6' or R.sup.7' is
--OCH.sub.2OP(O)(OH).sub.2. R.sup.4, R.sup.5, R.sup.x, and p are as
defined previously, and R.sup.y is a phosphono protecting
group.
[0087] In the first step, the free hydroxy group of a compound of
formula (Ia) is converted to the corresponding methylthiomethyl
ether (--OCH.sub.2SCH.sub.3) group. This conversion may be
accomplished by either one of the two procedures (1a--the
dimethylsulfide method) and (1b--the dimethylsulfoxide method). The
dimethylsulfide method for converting alcohols to methylthiomethyl
ethers is reported in Medina et al, Tet. Lett., 1988, pp.
3773-3776, the relevant portions thereof are hereby incorporated by
reference. The dimethylsulfoxide method is the well-known reaction
commonly known as the Pummerer reaction.
[0088] It should be noted that the reactivity of a hydroxy group
differs depending on its location on the taxane derivative starting
material of formula (Ia). Although in general the 2'-hydroxy group
is more reactive in acylation reactions than the 7-hydroxy group
which in turn is more reactive than the 10-hydroxy group, it has
been found that, surprisingly with the dimethylsulfide method, the
7-hydroxy is more readily converted into the methylthiomethyl ether
than the 2'-hydroxy group. The tertiary hydroxy group at C-1 is
usually the least reactive. The difference in hydroxy reactivity
may be exploited in controlling the site and degree of
methylthiomethylation.
[0089] Thus with a compound of formula (Ia) wherein R.sup.1a and
R.sup.2a are both hydroxy, the predominant methylthiomethylation
product is the corresponding 7-O-methylthiomethyl ether with the
dimethylsulfide method. In order to obtain a compound of formula
(Ib) wherein R.sup.1b is methylthiomethoxy, without also converting
the 7-hydroxy group, if present, into a methylthiomethyl ether, the
7-hydroxy group is blocked with a conventional hydroxy protecting
group such as triethylsilyl. Similarly, 10-methylthiomethyl ether
may be obtained without also converting the 7- and/or 2'-hydroxy
groups, if present, when the latter groups are blocked by the same
of different hydroxy protecting groups. Even though the 7-hydroxy
is the preferential methylthiomethylation site in the
dimethylsulfide method, it is still preferable to protect the
2'-hydroxy group if the 7-monomethylthiomethyl ether is the desired
product.
[0090] Moreover, the reaction conditions may be manipulated to
favor the formation of bis- or tris-methylthiomethyl ether taxane
derivatives. For example, in the case of paclitaxel, increasing
reaction time or using a larger excess of the methylthiomethylating
reagents can result in a higher ratio of 2',7-bis(methylthiomethyl)
ether paclitaxel in the product mixture.
[0091] Returning now to Scheme V, in procedure (1a) a compound of
formula (Ia) is treated with dimethylsulfide and an organic
peroxide such as benzoyl peroxide. The reaction is carried out in
an inert organic solvent such as acetonitrile, methylene chloride
and the like at a temperature conducive to product formation;
typically the reaction is carried at a temperature range of from
about -40.degree. C. to about ambient temperature. Dimethylsulfide
and benzoyl peroxide are used in excess relative to the taxane
derivative starting material (Ia), and dimethylsulfide is used in
excess relative to benzoyl peroxide.
[0092] The relative amounts of starting materials used will depend
on the degree of methylthiomethylation to be achieved. Thus when
one free hydroxy group of the taxane derivative starting material
(Ia) is to be converted to the methylthiomethyl ether,
dimethylsulfide and benzoyl peroxide may be used in up to 10 fold
excess relative to taxane derivative (Ia); and preferably,
dimethylsulfide is used in about two to three fold excess relative
to benzoyl peroxide. In the case where the starting material (Ia)
has both 2'- and 7-hydroxy groups, the amount of
2',7-bis(methylthiomethyl)ether obtained increases with the
relative amounts of dimethylsulfide and benzoyl peroxide. When
2',7-bis(methylthiomethyl) ether is the desired product,
dimethylsulfide is preferably used in about 15 to about 20 fold
excess of the taxane derivative starting material; and benzoyl
peroxide is used in about 5 to about 10 fold excess relative to the
taxane derivative starting material.
[0093] Alternatively, a compound of formula (Ib) may be prepared by
reacting a compound of formula (Ia) with dimethylsulfoxide and
acetic anhydride (procedure 1b). This procedure is suitable for
derivatizing a non-2'-hydroxy group into its methylthiomethyl
ether. In procedure (1b), a compound of formula (Ia) is dissolved
in dimethylsulfoxide and acetic anhydride is added to the solution.
The reaction is usually carried out at room temperature, and for
18-24 hours to produce the monomethylthiomethyl ether.
[0094] In the second step of the reaction sequence, the
methylthiomethyl ether is converted to the corresponding protected
phosphonooxymethyl ether. The methylthiomethyl to protected
phosphonooxymethyl conversion may be accomplished by the general
method reported in Veeneman et al, Tetrahedron, 1991, v47, pp.
1547-1562, the relevant portions thereof are hereby incorporated by
reference. Thus, a compound of formula (Ib) with at least one
methylthiomethyl ether group is treated with N-iodosuccinimide and
a protected phosphoric acid such as dibenzyl phosphate. The
reaction is carried out in an inert organic solvent such as
tetrahydrofuran or a halogenated hydrocarbon such as
1,2-dichloroethane or methylene chloride, and optionally in the
presence of a dehydrating agent such as molecular sieves. A
catalyst such as silver trifluoromethanesulfonate may also be added
to accelerate the reaction. The reaction is carried out at a
temperature ranging from about 0.degree. C. to about room
temperature, preferably at room temperature. N-Iodosuccinimide and
the protected phosphoric acid are used in about the same molar
equivalent as the methylthiomethylether (Ib), but preferably they
are used in slight excess, for example about 1.3 to about 1.5
equivalents relative to compound of formula (Ib).
[0095] In the third step of the reaction sequence, the phosphono
protecting group and hydroxy protecting group, if present, are
removed. The deblocking is accomplished by conventional methods
well known in the art such as acid- or base-catalyzed hydrolysis,
hydrogenolysis, reduction, and the like. For example, catalytic
hydrogenolysis can be used to remove the benzyl phosphono
protecting group as well as the benzyloxycarbonyl hydroxy
protecting group. Deprotecting methodologies may be found in
standard texts such as Greene and Wutz, or McOmie, supra. Needless
to say if a compound of formula (Ia) contains hydroxy groups in
radical R.sup.x, said hydroxy groups are preferably protected with
suitable hydroxy protecting groups until deprotected in this last
step.
[0096] As indicated earlier the procedure in Scheme V may be
modified in accordance with the teaching contained herein by one
skilled in the art to arrive at taxane derivatives of formula A in
which m 1, 2 or 3. As examples, Schemes Va and Vb specifically
illustrate how one skilled in the art can modify the teaching
contained herein to arrive at certain compounds of formula A
wherein at least one substitutent is
--OCH.sub.2OCH.sub.2OCH.sub.2OP(O)(OH).sub.2. Similarly other
compounds of formula A in which m is 2 or 3 can be readily
obtaiined. 18 19
[0097] The base salts of a compound of formula (I) may be formed by
conventional techniques involving contacting a compound of formula
(I) free acid with a metal base or with an amine. Suitable metal
bases include hydroxides, carbonates and bicarbonates of sodium,
potassium, lithium, calcium, barium, magnesium, zinc, and aluminum;
and suitable amines include triethylamine, ammonia, lysine,
arginine, N-methylglucamine, ethanolamine, procaine, benzathine,
dibenzylamine, tromethamine (TRIS), chloroprocaine, choline,
diethanolamine, triethanolamine and the like. The base salts may be
further purified by chromatography followed by lyophilization or
crystallization.
[0098] TAXANE DERIVATIVES STARTING MATERIALS
[0099] The processes described above may be applied to any taxane
derivatives of the formula T-[OH].sub.n to form compounds of
formula (A). Many examples of T-[OH].sub.n have been reported in
the literature and some of which are listed below. (a) paclitaxel;
(b) Taxotere.RTM.; (c) 10-desacetylpaclitaxel; (d) taxane
derivatives disclosed in PCT application 93/06079 (published Apr.
1, 1993) having the formula 20
[0100] wherein R.sub.1 is --OR.sub.6, --SR.sub.7, or
--NR.sub.8R.sub.9; R.sub.2 is hydrogen, alkyl, alkenyl, alkynyl,
aryl, or heteroaryl; R.sub.3 and R.sub.4 are independently
hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, or acyl,
provided, however, that R.sub.3 and R.sub.4 are not both acyl;
R.sub.5 is --COR.sub.10, --COOR.sub.10, --COSR.sub.10,
--CONR.sub.8R.sub.10, --SO.sub.2R.sub.11, or
--POR.sub.12R.sub.13;R.sub.6 is hydrogen, alkyl, alkenyl, alkynyl,
aryl, heteroaryl, hydroxy protecting group, or a functional group
which increases the water solubility of the taxane derivative;
R.sub.7 is alkyl, alkenyl, alkynyl, aryl, heteroaryl, or sulfhydryl
protecting group; R.sub.8 is hydrogen, alkyl, alkenyl, alkynyl,
aryl, heteroaryl; R.sub.9 is an amino protecting group; R.sub.10 is
alkyl, alkenyl, alkynyl, aryl, heteroaryl; R.sub.11 is alkyl,
alkenyl, alkynyl, aryl, heteroaryl, --OR.sub.10, or
--NR.sub.8R.sub.14; R.sub.12 and R.sub.13 are independently alkyl,
alkenyl, alkynyl, aryl, heteroaryl, --OR.sub.10, or
--NR.sub.8R.sub.14; R.sub.14 is hydrogen, alkyl, alkenyl, alkynyl,
aryl, heteroaryl; R.sub.15 and R.sub.16 are independently hydrogen,
hydroxy, lower alkanoyloxy, alkenoyloxy, alkynoyloxy, aryloyloxy or
R.sub.15 and R.sub.16 together form an oxo; R.sub.17 and R.sub.18
are independently hydrogen, hydroxy, lower alkanoyloxy,
alkenoyloxy, alkynoyloxy, aryloyloxy or R.sub.17 and R.sub.18
together form an oxo; R.sub.19 and R.sub.20 are independently
hydrogen or hydroxy or lower alkanoyloxy, alkenoyloxy, alkynoyloxy,
or aryloyloxy; R.sub.21 and R.sub.22 are independently hydrogen or
lower alkanoyloxy, alkenoyloxy, alkynoyloxy, or aryloyloxy or
R.sub.21 and R.sub.22 together form an oxo; R.sub.24 is hydrogen or
hydroxy or lower alkanoyloxy, alkenoyloxy, alkynoyloxy, or
aryloyloxy; or R.sub.23 and R.sub.24 together form an oxo or
methylene or R.sub.23 and R.sub.24 together with the carbon atom to
which they are attached form an oxirane ring or R.sub.23 and
R.sub.22 together with the carbon atom to which they are attached
form an oxetane ring; R.sub.25 is hydrogen, hydroxy, or lower
alkanoyloxy, alkenoyloxy, alkynoyloxy, or aryloyloxy; or R.sub.26
is hydrogen, hydroxy, or lower alkanoyloxy, alkenoyloxy,
alkynoyloxy, or aryloyloxy; or R.sub.26 and R.sub.25 taken together
form an oxo; and R.sub.27 is hydrogen, hydroxy or lower alkoxy,
alkanoyloxy, alkenoyloxy, alkynoyloxy, or aryloyloxy; (e) taxane
derivatives disclosed in U.S. Pat. No. 5,227,400
3'-desphenyl-3'-(2-furyl) or 3'-(2-thienyl) derivatives of
paclitaxel, Taxotere.RTM.; (f) taxane derivatives disclosed in EP
534,709 published Mar. 31, 1993 (paclitaxel derivatives in which
the sidechain phenyl groups are independently replaced with
naphthyl, styryl or substituted phenyl). See also PCT 92/09589
published Jun. 11, 1992; (g) taxane derivatives disclosed in EP
534,707 published Mar. 31, 1993 (paclitaxel derivatives in which
the 3'-N-benzoyl group is replaced with ethoxycarbonyl or
methoxycarbonyl); (h) PCT Application 93/06093 published Apr. 1,
1993 (10-desacetoxy derivatives of paclitaxel and Taxotere.RTM.);
(i) EP 524,093 published Jan. 20, 1993 (10-, 7-, or
7,10-bis-O-(N-substituted carbamoyl taxane derivatives); (j)
9-.alpha.-hydroxy analog of paclitaxel is disclosed in Klein,
"Synthesis of 9-Dihydrotaxol: A New Bioactive Taxane," Tetrahedron
Letters, 1993, 34(13):2047-2050; (k) 14-.beta.-hydroxy analog of
paclitaxel and Taxotere.RTM. prepared from
14.beta.-hydroxy-10-deacetylbaccatin III are disclosed at the 205th
ACS National Meeting in Colorado, 1993. (Med. Chem. Division,
Abstract No. 28); and (1) other taxanes, such as C7-fluorotaxanes
and various C10-substituted taxanes, as disclosed in European
Patent Application 577,082A1 published Jan. 5, 1994, which is
herein incorporated by reference in its entirety.
[0101] The free hydroxy group or groups of taxane derivatives may
be converted by conventional methods to the corresponding ester or
carbonate; for example in compounds of formula (Ia) one of
R.sup.1a, R.sup.2a or R.sup.3a is --OC(O)R.sup.x or --OC(O)OR.sup.x
and R.sup.x is as previously defined. Thus, a taxane derivative
T-OH may be reacted with a compound of the formula L-C(O)OR.sup.x
(L being a leaving group) such as a chloroformate in the presence
of a base such as tertiary amine to give the corresponding
carbonate; for example, paclitaxel reacts with ethyl chloroformate
in the presence of diisopropylethylamine to provide
2'-O-ethyloxycarbonylpaclitaxel. T-OH may also react with a
carboxylic acid R.sup.xCO.sub.2H or an acylating equivalent thereof
(e.g. an anhydride, active ester or an acyl halide) to provide the
corresponding ester. Needless to point out when R.sup.x in
L-C(O)OR.sup.x, or R.sup.xCO.sub.2H or an acylating equivalent
thereof contains hydroxy groups, they are preferably protected with
suitable hydroxy protecting groups.
[0102] Additionally, taxane derivatives T-[OH].sub.n may be
prepared by acylating a taxane moiety having a C13-hydroxy group
with an appropriately substituted 3-amino-2-hydroxypropanoic acid,
an acylating equivalent thereof, or a precursor thereof. Suitable
precursors of substitutd 3-amino-2-hydroxypropanoic acid are for
example azetidinones of formula (III). This acylation reaction is
exemplified in the coupling of hydroxy protected baccatin III or
hydroxy protected 10-deacetylbaccatin III and a phenylisoserine
derivative to give paclitaxel derivatives as disclosed in e.g.
Denis et al, U.S. Pat. Nos. 4,924,011 and 4,924,012; and in the
coupling of a protected baccatin III and an azetidinone to give
paclitaxel and derivatives thereof as disclosed in EP Published
Application 400,971 published Dec. 5, 1990 (now U.S. Pat. No.
5,175,315) and U.S. Pat. No. 5,229,526.
[0103] The process as disclosed in EP 400,971 (the Holton process)
involves reacting
1-benzoyl-3-(1-ethoxy)ethoxy-4-phenyl-2-azetidinone with
7-O-triethylsilylbaccatin III in the presence of
N,N-dimethylaminopyridine and pyridine at 25.degree. C. for 12
hours; paclitaxel is obtained after the various hydroxy protecting
groups are removed. An improvement of the Holton process is
reported by Ojima et al in "New and Efficient Approaches to the
Semisynthesis of Taxol and its C-13 Side Chain Analogs by Means of
.beta.-Lactam Synthon Method" Tetrahedron, 1992, 48(34):6985-7012.
Ojima's process involves first generating the sodium salt of
7-triethylsilylbaccatin III with sodium hydride; this salt is then
reacted with chiral 1-benzoyl-3-(1-ethyoxy)eth-
oxy-4-phenyl-2-azetidinone to provide paclitaxel after removal of
the hydroxy protecting groups. In U.S. Pat. No. 5,229,526 Holton
discloses the coupling of a metal alkoxide of baccatin III or a
derivative thereof with a 2-azetidinone to provide taxanes with C13
sidechain. This process is said to be highly diastereoselective;
therefore racemic mixtures of the sidechain precursor 2-azetidinone
may be used. Recently, Ojima et al reported in "A Highly Efficient
Route to Taxotere by the .beta.-Lactam Synthon Method," Tetrahedron
Letters, 1993, 34(26):4149-4152, the coupling of metal alkoxides of
7,10-bis-O-(trichloroethoxycarbonyl)-10-de- acetylbaccatin III with
chiral 1-(t-butoxycarbonyl)-4-phenyl-3-(protected
hydroxy)-2-azetidinone to give Taxotere.RTM. after deprotection.
The relevant portions of all references cited above are hereby
incorporated by reference.
[0104] The baccatin/azetidinone process generalized to the
preparation of compounds of formula (Ia) is illustrated in Scheme
VI. Again, other taxane derivatives not specifically encompassed
within the formula (Ia) may also be prepared by this process by
employing appropriate starting materials. 21
[0105] In Scheme VI, R.sup.2' is hydrogen, and R.sup.2d is
hydrogen, protected hydroxy or --OC(O)OR.sup.x; or R.sup.2' is
fluoro, and R.sup.2d is hydrogen; R.sup.3d is hydrogen,
--OC(O)R.sup.x, C.sub.1-6alkyloxy, protected hydroxy or
--OC(O)OR.sup.x; one of R.sup.6d or R.sup.7d is hydrogen and the
other is hydroxy, protected hydroxy or C.sub.1-6 alkanoyloxy; or
R.sup.6d and R.sup.7d together form an oxo group; P is a hydroxy
protecting group; M is hydrogen or a Group IA metal such as
lithium, sodium or potassium; and p, R.sup.4, R.sup.5 and R.sup.x
are as previously defined. The reaction may be conducted according
to the procedure disclosed in EP 400,971 wherein the baccatin III
derivative of formula (II) wherein M is hydrogen is reacted with an
azetidinone of formula (III) in the presence of an organic base
such as N,N-dimethylaminopyridine. Preferably, however, the
baccatin III derivative is first converted to a 13-alkoxide by
treating the former with a strong base such as hydrides,
alkylamides, and bis(trialkylsilyl)amides of Group IA metals as
disclosed in U.S. Pat. No. 5,229,526 and the Ojima references,
supra. More preferably, the 13-alkoxide is a lithium alkoxide. The
formation of a lithium salt may be achieved by reacting a compound
of formula (II) wherein M is hydrogen with a strong metal base,
such as lithium diisopropylamide, C.sub.1-6 alkyllithium, lithium
bis(trimethylsilyl)amide, phenyllithium, lithium hydride, or the
like base. Needless to point out that if a compound of formula (II)
contains hydroxy groups in radical R.sup.x, said hydroxy groups are
preferably protected with suitable hydroxy protecting groups.
[0106] The coupling reaction between a taxane of formula (II) and
an azetidinone of formula (III) is conducted in an inert organic
solvent such as tetrahydrofuran at reduced temperature in the range
of about 0.degree. C. to about -78.degree. C. The azetidinones of
formula (III) may be used as a racemic mixture to couple with
taxane metal alkoxides of formula (II) in which M is a group 1A
metal; in such case, the azetidinone reactant is preferably used in
at least 2 equivalents relative to the taxane reactant, and more
preferably from about 3 to about 6 equivalents. Chiral azetidinones
may also be used, and in such case one equivalent of the
azetidinone relative to the taxane may be sufficient, but
preferably the azetidinone is used in slight excess, for example up
to 1.5 equivalents.
[0107] The hydroxy protecting groups may be the same or they may be
chosen in a manner to allow the selective removal of one or more
protecting groups without substantially affecting the others; for
example, in a compound of formula (Id), R.sup.2d and PO may be both
triethylsilyloxy, and R.sup.3d may be benzyloxycarbonyl; catalytic
hydrogenolysis in the presence of palladium on carbon removes the
benzyloxycarbonyl protecting group without removing the
triethylsilyl group. Thus, the hydroxy protecting groups of a
compound of formula (Id) may be selectively removed to provide a
compound of formula (Ia).
[0108] Compounds of formula (II) are either known in the
literature, e.g baccatin III, 10-deacetylbaccatin III and their
hydroxy protected derivatives, or can be prepared from the known
compounds by conventional conventional methods, e.g converting a
hydroxy group to a carbonate. Additional compounds of formula (II)
may be prepared according to procedures described hereinbelow in
the section PREPARATION OF STARTING MATERIALS.
[0109] Compounds of formula (III) can be prepared from a compound
of (IIIa) according to the general method described in EP 400,971
and Ojima et al, Tetrahedron, 48:6985-7012, 1992. 22
[0110] Thus a compound of formula (IIIa) is first treated with a
base such as n-butyllithium or triethylamine, and then followed by
a compound of the formula R.sup.4(O).sub.pCO-L where L is a leaving
group to provide a compound of formula (III).
[0111] Compounds of (IIIa) may be prepared according to the general
method disclosed in EP 400,971 by going through an intermediate
compound 3-acetoxy-4-substituted-2-azetidinone (IIIb); or by the
method disclosed in U.S. Pat. No. 5,229,526 by going through an
intermediate compound
3-triethylsilyloxy-4-substituted-2-azetidinone. In an improved
process a compound (IIIb) may be obtained by condensing
acetoxyacetyl chloride with a bis-imine followed by hydrogenolysis
or acid cleavage to remove the N-imine group; this process is shown
in the following scheme in which R.sup.5' is an optionally
substituted aryl or a heteroaryl group such as furyl or thienyl.
This process is disclosed in co-pending application U.S. Ser. No.
08/165,610 filed Dec. 13, 1993 which is hereby incorporated by
reference. 23
[0112] The products (IIIb) obtained from these cycloaddition
reactions are usually a racemic mixture of the two
cis-azetidinones. The racemic mixture may be resolved by
conventional methods such as conversion to diastereomers,
differential absorption on column packed with chiral adsorbents, or
enzymatically. For example, a racemic mixture of compounds of
formula (IIIb) may be contacted with an enzyme that catalyzes the
hydrolysis of an ester, for example an esterase or a lipase, to
selectively cleave the 3-acyl group of one enantiomer without
affecting the other. (See e.g. Brieva et al, J. Org. Chem., 1993,
58:1068-1075; also co-pending U.S. application Ser. No. 092,170
filed Jul. 14, 1993, European Patent Application Number 552041,
published Jul. 21, 1993). Alternatively, the racemic mixture may be
first subjected to base-catalyzed hydrolysis to remove the 3-acyl
group and to generate a racemic mixture of the corresponding
3-hydroxy .beta.-lactam; the racemic mixture of 3-hydroxy
.beta.-lactam is then contacted with an enzyme capable of
catalyzing acylation of an hydroxy group to selectively acylate the
hydroxy group of one enantiomer without affecting the other. Or the
racemic mixture of 3-hydroxy .beta.-lactam may be acylated with a
chiral carboxylic acid, and the resulting diastereomeric mixture
may then be separated using methods known in the art, and the
chiral auxiliary removed to provide the desired enantiomer.
[0113] Ojima et al, in J. Org. Chem., 56:1681-1683, 1991; Tet.
Lett., 33:5737-5740, 1992; and Tetrahedron, 48:6985-7012, 1992
reported the synthesis of a number of chiral azetidinones of
formula (IIIa) and/or the corresponing N-(p-methoxyphenyl)
congener; wherein P is the hydroxy protecting group
triisopropylsilyl; and R.sup.5 is 4-methoxyphenyl,
3,4-dimethyoxyphenyl, phenyl, 4-fluorophenyl,
4-trifluoromethylphenyl, 2-furyl, 2-phenylethenyl,
2-(2-furyl)ethenyl, 2-methylpropyl, cyclohexylmethyl, isopropyl,
phenethyl, 2-cyclohexylethyl, or n-propyl. Other references for
making azetidinones fo formula (IIIa) and/or (III) can be found in
European Patent Applications 0,534,709 A1, 0,534,708 A1, and
0,534,707 A1, all three published on Mar. 31, 1993; in PCT
application WO 93/06079 published on Apr. 1, 1993; in Bioorganic
and Medicinal Chemistry Letters, 3, No. 11, pp 2475-2478 (1993);
also in Bioorganic and Medicinal Chemistry Letters, 3, No. 11, pp
2479-2482 (1993); in J. Org. Chem., 58, pp 1068-1075; in
Tetrahedron Letters, 31, No. 44, pp 6429-6432 (1990); in Bioorganic
and Medicinal Chemistry Letters, 3, No. 11, pp 2467-2470 (1993);
European Application 552,041 published on Jul. 21, 1993; and in our
copending U.S. application Ser. No. 092,170 filed on Jul. 14, 1993.
The relevant portions of all aforementioned references are hereby
incorporated by reference. Other azetidinones within the definition
of formula (III) but are not specifically disclosed in these
references may be prepared by a person skilled in the art following
the methodologies generally known in the art.
[0114] BIOLOGICAL EVALUATION
[0115] Compounds of formula (B) of the present invention are useful
intermediates for novel antitumor agents of formula (A). In
addition, some compounds within the scope of formula (B), namely
compounds of formula (B'), were themselves found to be antitumor
agents. Biological Section I below demonstrates the antitumor
activity of the compounds of formula (A). On the other hand,
Biological Section II below demonstrates the antitumor activity of
the compounds of formula (B').
[0116] Biological Section I
[0117] In vitro cytotoxicity data
[0118] The compounds of formula (A) showed in vitro cytoxicity
activity against human colon carcinoma cells HCT-116 and
HCT-116/VM46. The HCT-116/VM46 cells are cells that have been
previously selected for teniposide resistance and express the
multi-drug resistance phenotype, including resistance to
paclitaxel. Cytotoxicity was assessed in HCT-116 human colon
carcinoma cells by XTT (2,3-bis(2-methoxy-4-nitro-5-sulfpheny-
l)-5-[(phenylamino)carbonyl]2H-tetrazolium hydroxide) assay as
reported in D. A. Scudiero, et al., "Evaluation of soluble
tetrazolium/formazan assay for cell growth and drug sensitivity in
culture using human and other tumor cell lines," Cancer Res.
48:4827-4833, 1988. Cells were plated at 4000 cells/well in 96 well
microtiter plates and 24 hours later drugs were added and serial
diluted. The cells were incubated at 37.degree. C. for 72 hours at
which time the tetrazolium dye, XTT, was added. A dehydrogenase
enzyme in live cells reduces the XTT to a form that absorbs light
at 450 nm which can be quantitated spectrophotometrically. The
greater the absorbance, the greater the number of live cells. The
results are expressed as an IC.sub.50, which is the drug
concentration required to inhibit cell proliferation (i.e.,
absorbance at 450 nm) to 50% of that of untreated control cells.
The IC.sub.50 values for representative compounds evaluated in this
assay are given in Table I.
1TABLE I In vitro cytotoxicity data against human colon carcinoma
cells. IC.sub.50 (.mu.M) Compound.sup.1 HCT-116 HCT-116/VM46
Texotere .RTM. 0.004 0.213 paclitaxel 0.004 0.44 Example 1 0.0158
1.24 Example 3 0.312 6.25 Example 4 0.0457 >6.3 .sup.1Examples 1
and 4 as free acid; example 3 as sodium salt.
[0119] The compound 7-O-methylthiomethylpaclitaxel (Example 1 (a)
was also tested in the cytotoxicity assay and it showed IC.sub.50
of 0.003 .mu.M against HCT-116 and 0.025 .mu.M against
HCT-116/VM46.)
[0120] In vivo antitumor activity
[0121] Balb/c x DBA.sub.2 F.sub.1 (CDF.sub.1) hybrid mice were
implanted subcutaneously (sc) with 0.1 ml of a 2% (w/v) brei of
M109 lung carcinoma (as described in W. Rose "Evaluation of Madison
109 Lung Carcinoma as a Model for Screening Antitumor Drugs,"
Cancer Treatment Reports, 65, No. 3-4 pp. 299-312 (1981). The test
compounds and reference drug, paclitaxel, were administered
intravenously to groups of mice; each group received a compound at
a different dose level, and three or four different dose levels
were evaluated per compound. Mice were followed daily for survival
until their death or about day 75 post-tumor implant, whichever
occurred first. One group of mice per experiment remained untreated
and served as the control. Tumors were also measured once or twice
weekly and the size in mm was used to estimate tumor weight
according to the published procedure (ibid).
[0122] Median survival times of compound-treated (T) mice were
compared to the median survival time of parallel control (C) mice.
The ratio of the two values for each compound-treated group of mice
was multiplied by 100 and expressed as a percentage (i.e., % T/C)
in Table II for representative compounds. Additionally, the
difference between the median time for treated groups and that for
the control group to grow tumor to 1 gm, expressed as T-C values in
days, is also shown in Table II. The greater the T-C value, the
greater the delay in primary tumor growth. Compounds showing %
T/C.gtoreq.125% and/or T-C.gtoreq.4.0 days are considered to be
active in the M109 SC model.
2 TABLE II Maximum Effect Opt. Dose Compound % T/C T-C (days)
(mg/kg/inj;) Example 1.sup.d 131 14.0 45.sup.a paclitaxel 134 14
48/24.sup.a,c Example 3.sup.d 160 18.8 24.sup.b paclitaxel 151 15
18.sup.b .sup.aCompound was admisnistered i.v. once daily, on days
4, 5, 6, 7 and 8 post-tumor implant. .sup.bCompound was
administered i.v. once daily, on days 5, 6, 7, 8 and 9 post-tumor
implant. .sup.cHigher dose achieved maximum increase in lifespan;
lower does associated with causing maximum delay in tumor growth.
.sup.dsodium salt.
[0123] Compound of Example 3 (as the triethanolamine salt) was
further evaluated in murine and human xenograft tumor models (M109,
A2780/cDDP--human ovarian carcinoma resistant to cisplatin, and
HCT-116--human colon carcinoma) against paclitaxel as positive
control. The A2780/cDDP model is described in Rose and Basler, In
Vivo, 1990, 4:391-396; the HCT-116 model is described in Rose and
Basler, In Vivo, 1989, 3:249-254. M109 was passaged sc biweekly in
Balb/C mice and implanted sc into CDF1 mice for antitumor
evaluation. A2780/cDDP and HCT-116 were grown in athymic mice for
both passage (every two to three weeks) and therapy experiments.
Compound of Example 3 was administered iv in water, or orally in
water with a few drops of Tween 80, while paclitaxel was either
suspended in water plus Tween 80, or dissolved in
cremophore/ethanol (50%/50%) and diluted with saline. The treatment
regimen for the sc M109 tumor tests was once daily for 5
consecutive days beginning on Day 4 post tumor implant. For the
human tumor xenograft tests, compounds were given once daily every
other day for five administrations beginning when the tumors were
staged to between 50 to 100 mg.
[0124] In one M109 experiment, compound of Example 3 administered
iv achieved max. % T/C of 155 (T-C of 19 days) at 36 mg/kg/inj.
(cf. paclitaxel max. % T/C of 132 (T-C of 13 days) at 36 or 18
mg/kg/inj.). In the same experiment, compound of Example 3
administered orally achieved a max. % T/C of 158 (T-C of 22.8 days)
at a dose of 160 mg/kg/adm. while paclitaxel at the same dose
(highest tested) suspended in water and Tween 80 did not show
activity. In another M109 experiment, iv administered compound of
Example 3 produced max. % T/C of 170 (T-C of 17 days) at 48
mg/kg/inj. (cf. paclitaxel max. % T/C of 167 (T-C of 14 days) at 48
or 36 mg/kg/inj.). In the same experiment, orally administered
compound of Example 3 produced max. % T/C of 172 (T-C of 17 days)
at a dose of 200 mg/kg/adm. while paclitaxel dissolved in
cremophore/ethanol/saline did not show activity at 60/mg/kg/inj. In
this experiment, paclitaxel dissolved in cremophore/ethanol/saline
could not be administered at greater than 60/mg/kg/inj. due to
solubility and toxicity constraints.
[0125] In the A2780/cDDP experiment, iv administered compounds of
Example 3 showed max. T-C value of 29.8 days at 36 mg/kg/inj (cf.
paclitaxel max. T-C of 26.3 days at 36 mg/kg/inj.). Orally
administered compound of Example 3 produced max. T-C of 20 days at
a dose of 160 mg/kg/adm. In the HCT-116 experiment, iv treatment
with 24 or 36 mg/kg/inj. of paclitaxel produced 6 cures of 7 or 6
cures of 8 treated mice, respectively, and 160 or 240 mg/kg/adm. of
oral compound of Example 3 cured 6 or 7 of 8 treated mice,
respectively. Cure means tumor-free on Day 80 post tumor
implant.
[0126] The triethanolamine salt of compound of example 1 was also
found to have oral activity in the M109 and HCT-116 models.
[0127] It is well appreciated in the art that there will be some,
usually slight, variations in the anti-tumor activity depending on
what particular salt form is employed.
[0128] The pharmaceutically acceptable salt of phosphonooxymethyl
ethers of taxane derivatives of formula (A) exhibit improved water
solubility over paclitaxel thereby allowing more convenient
pharmaceutical formulations. Without being bound by theory, it is
believed that the phosphonooxymethyl ethers of the present
invention are prodrugs of paclitaxel or derivative thereof; the
phosphonooxymethyl moiety being cleaved upon contact with
phosphatase in vivo to generate subsequently the parent
compound.
[0129] Biological Section II
[0130] Mice M109 Model
[0131] Balb/c x DBA/2 F.sub.1 hybrid mice were implanted
intraperitoneally, as described by William Rose in Evaluation of
Madison 109 Lung Carcinoma as a Model for Screening Antitumor
Drugs, Cancer Treatment Reports, 65, No. 3-4 (1981), with 0.5 mL of
a 2% (w/v) brei of M109 lung carcinoma.
[0132] Mice were treated with compound under study by receiving
intraperitoneal injections of various doses on either days 1, 5 and
9 post-tumor implant or days 5 and 8 post-implant. Mice were
followed daily for survival until approximately 75 - 90 days
post-tumor implant. One group of mice per experiment remained
untreated and served as the control group. Median survival times of
compound-treated (T) mice were compared to the median survial time
of the control (C) mice. The ratio of the two values for each
compound-treated group of mice was multiplied by 100 and expressed
as a percentage (i.e. % T/C) in Table III for representative
compounds of formula (B').
3 TABLE III EXAMPLE T/C (mg/kg/inj.; NUMBER schedule in days) 14
(b) 143 (12; d. 5 + 9) 15 192 (8; d. 5 + 9)
[0133] As shown above, compounds of formula (A) and (B') of the
instant invention are effective tumor inhibiting agents, and thus
are useful in human and/or veterinary medicine. Thus, another
aspect of the instant invention concerns a method for inhibiting
human and/or other mammalian tumors which comprises administering
to a tumor bearing host an antitumor effective amount of a compound
of formula (A) or (B').
[0134] Compounds of formulas (A) and (B') of the present invention
may be used in a manner similar to that of paclitaxel; therefore,
an oncologist skilled in the art of cancer treatment will be able
to ascertain, without undue experimentation, an appropriate
treatment protocol for administering a compound of the present
invention. The dosage, mode and schedule of administration for
compounds of this invention are not particularly restricted, and
will vary with the particular compound employed. Thus a compound of
the present invention may be administered via any suitable route of
administration, preferably parenterally; the dosage may be, for
example, in the range of about 1 to about 100 mg/kg of body weight,
or about 20 to about 500 mg/m.sup.2. Compounds of formula (A) and
(B) may also be administered orally; oral dosage may be in the
range of about 5 to about 500 mg/kg of body weight. The actual dose
used will vary according to the particular composition formulated,
the route of administration, and the particular site, host and type
of tumor being treated. Many factors that modify the action of the
drug will be taken into account in determining the dosage including
age, weight, sex, diet and the physical condition of the
patient.
[0135] The present invention also provides pharmaceutical
compositions (formulations) containing an antitumor effective
amount of a compound of formula (A) or (B') in combination with one
or more pharmaceutically acceptable carriers, excipients, diluents
or adjuvants. Examples of formulating paclitaxel or derivatives
thereof may be found in, for example, U.S. Pat. Nos. 4,960,790 and
4,814,470, and such examples may be followed to formulate the
compounds of this invention. For example, compounds of the present
invention may be formulated in the form of tablets, pills, powder
mixtures, capsules, injectables, solutions, suppositories,
emulsions, dispersions, food premix, and in other suitable forms.
They may also be manufactured in the form of sterile solid
compositions, for example, freeze dried and, if desired, combined
with other pharmaceutically acceptable excipients. Such solid
compositions can be reconstituted with sterile water, physiological
saline, or a mixture of water and an organic solvent, such as
propylene glycol, ethanol, and the like, or some other sterile
injectable medium immediately before use for parenteral
administration.
[0136] Typical of pharmaceutically acceptable carriers are, for
example, manitol, urea, dextrans, lactose, potato and maize
starches, magnesium stearate, talc, vegetable oils, polyalkylene
glycols, ethyl cellulose, poly(vinylpyrrolidone), calcium
carbonate, ethyl oleate, isopropyl myristate, benzyl benzoate,
sodium carbonate, gelatin, potassium carbonate, silicic acid. The
pharmaceutical preparation may also contain nontoxic auxiliary
substances such as emulsifying, preserving, wetting agents, and the
like as for example, sorbitan monolaurate, triethanolamine oleate,
polyoxyethylene monostearate, glyceryl tripalmitate, dioctyl sodium
sulfosuccinate, and the like.
[0137] In the following experimental procedures, all temperatures
are understood to be in Centigrade (C) when not specified. The
nuclear magnetic resonance (NMR) spectral characteristics refer to
chemical shifts (.delta.) expressed in parts per million (ppm)
versus tetramethylsilane (TMS) as reference standard. The relative
area reported for the various shifts in the proton NMR spectral
data corresponds to the number of hydrogen atoms of a particular
functional type in the molecule. The nature of the shifts as to
multiplicity is reported as broad singlet (bs), broad doublet (bd),
broad triplet (bt), broad quartet (bq), singlet (s), multiplet (m),
doublet (d), quartet (q), triplet (t), doublet of doublet (dd),
doublet of triplet (dt), and doublet of quartet (dq). The solvents
employed for taking NMR spectra are acetone-d.sub.6 (deuterated
acetone). DMSO-d.sub.6 (perdeuterodimethylsulfoxide), D.sub.2O
(deuterated water), CDCl.sub.3 (deuterochloroform) and other
conventional deuterated solvents. The infrared (IR) spectral
description include only absorption wave numbers (cm.sup.-1) having
functional group identification value.
[0138] Celite is a registered trademark of the Johns-Manville
Products Corporation for diatomaceous earth.
[0139] The abbreviations used herein are conventional abbreviations
widely employed in the art. Some of which are: MS (mass
spectrometry); HRMS (high resolution mass spectrometry); Ac
(acetyl); Ph (phenyl); v/v (volume/volume); FAB (fast atom
bombardment); NOBA (m-nitrobenzyl alcohol); min (minute(s)); h or
hr(s) (hour(s)); NIS (N-iodosuccinimide); BOC (t-butoxycarbonyl);
CBZ or Cbz (benzyloxycarbonyl); Bn (benzyl); Bz (benzoyl); TES
(triethylsilyl); DMSO (dimethylsulfoxide); THF (tetrahydrofuran);
HMDS (hexamethyldisilazane).
[0140] PREPARATION OF STARTING MATERIALS
[0141] The preparations of several specific starting materials
useful in the preparation of compounds of formula (A) are
exemplified below.
[0142] Preparation 1. 10-Desacetoxypaclitaxel 24
[0143] (a) 2',7-O-bis(2,2,2-trichloroethoxycarbonyl)-10-deacetyl
paclitaxel
[0144] 10-Deacetyl paclitaxel (140 mg, 0.173 mmol) in dry
dichloromethane (3.5 mL) was treated at 0.degree. C. with pyridine
(0.028 mL, 0.346 mmol) and trichloroethyl chloroformate (0.0724 mL,
0.260 mmol). After 1 h at this temperature, the cold bath was
removed and the mixture was stirred at room temperature overnight.
The solvent was evaporated and the residue chromatographed on
silica gel (30-50% ethyl acetate in hexane) to afford the title
compound as a foam (92.3 mg, 46%). Further elution afforded
unreacted starting material (35 mg, 25%), and
2',10-O-bis(2,2,2-trichloro- ethoxycarbonyl)-10-deacetylpaclitaxel
in 16% yield.
[0145] (b)
2',7-O-bis(2,2,2-trichloroethoxycarbonyl)-10-desacetoxy-11,12-d-
ihydropaclitaxel-10,12(18)-diene
[0146] The product obtained in step (a) (92.3 mg, 0.079 mmol) in
dry dichloromethane (2 mL) was treated at room temperature with
1,1,2-trifluoro-2-chlorotriethylamine (0.0384 mL, 0.238 mmol). The
solution was stirred overnight. The solvent was evaporated and the
residue purified by column chromatography (25% ethyl acetate in
hexane) to afford the title compound as a white powder (42.8 mg,
47.3%).
[0147] (c)
10-Desacetoxy-11,12-dihydropaclitaxel-10,12(18)-diene
[0148] The product of step (b) (39 mg, 0.034 mmol) was dissolved in
methanol (0.5 mL) and acetic acid (0.5 mL), and treated with
acid-washed zinc dust (66.4 mg, 1.020 mmol). The slurry was heated
at 40.degree. C. for 1 h, filtered and the filtrate evaporated.
Chromatography of the residue with 60% ethyl acetate/hexane gave
the title compound as a foam (22 mg, 81%).
[0149] (c) 10-Desacetoxypaclitaxel
[0150] The product of step (c) (22 mg, 0.028 mmol) in ethyl acetate
(0.7 mL) was hydrogenated at atmospheric pressure in the presence
of palladium on charcoal (10%, 14.7 mg, 0.014 mmol Pd) After 5.5 h
at RT, filtration (rinsing with ethyl acetate), evaporation and
chromatography (60% ethyl acetate in hexane) gave the title product
(15.0 mg, 68%) as a white foam.
[0151] Preparation 2. 7-Deoxy-7.alpha.-fluoropaclitaxel 25
[0152] (a)
2'-O-Benzyloxycarbonyl-7-deoxy-7.alpha.-fluoropaclitaxel
[0153] Diethylaminosulfur trifluoride (DAST, 18.7 .mu.L, 0.141
mmol) was dissolved in dry dichloromethane (0.5 mL), and this
solution was cooled to 0.degree. C. A solution of
2'-O-(benzyloxycarbonyl)paclitaxel (71 mg, 0.072 mmol) in
dichloromethane (1 mL) was added and the resulting solution was
kept at 0.degree. C. for 30 min and at room temperature for 4 h.
Then, water (0.15 mL) was added to the reaction mixture in order to
quench the reaction and the resultant mixture was concentrated to
leave a residue. The residue was chromatographed on a silica gel
column (being eluted with 40% ethyl acetate in hexane) to yield 61
mg (Y: 85.7%) of a 1:1 mixture of the title compound and
2'-O-benzyloxycarbonyl-8-desmethyl-- 7,8-cyclopropapaclitaxel.
[0154] (b) 7-Deoxy-7.alpha.-fluoropaclitaxel
[0155] The product mixture obtained in Step (a) (89 mg) was
dissolved in ethyl acetate (3 mL) and the mixture was stirred under
slightly over one atmospheric pressure of hydrogen in the presence
of palladium on charcoal (10% Pd, 29 mg, 0.027 mmol). After 12 h,
the solvent was removed, and the residue was purified by silica gel
chromatography (being eluted with 40% ethyl acetate in hexane) to
afford 67.7 mg of the title compound, along with
8-desmethyl-7,8-cyclopropapaclitaxel.
[0156] The following HPLC method was used to separate the
7-deoxy-7.alpha.-fluoropaclitaxel and
8-desmethyl-7,8-cyclopropapaclitaxe- l.
4 Equipment Pump: PE Series 4 Column: Shandon Hypercarb
(graphitized carbon), 7 .mu., 100 .times. 4.6 mm; #59864750
(information on preparative size columns may be obtained from
Keystone Scientific, Bellefonte, PA) Injector: PE ISS-100 Detector:
HP-1040M Conditions Mobile Phase: 85:15 methylene chloride: hexane
Separation not lost at 80:19:1 methylene chloride: hexane:
isopropyl alcohol Flow Rate: 2.5 mL/min Detector: 254 nm Diluent:
Sample dissolved in methylene chloride Preparation 3.
7-Deoxy-7.alpha.-fluorobaccatin III
[0157] 26
[0158] To a dry flask under an inert atmosphere was added
2'-O-(benzyloxycarbonyl)paclitaxel (4 g, 4 mmol) and dry toluene
(80 mL). The resulting slurry was stirred at ambient temperature
while dry tetrahydrofuran (16 mL) was added dropwise until a
colorless solution resulted. The above solution was cooled to
-78.degree. C. in a dry ice/acetone bath then treated with
diethylaminosulfur trifluoride (DAST, 1.2 mL, 2.5 eq.). The
reaction mixture was allowed to stir for 16 h as it gradually
warmed to ambient temperature. The resulting suspension was
filtered and the filtrate (diluted with ethyl acetate (30 mL)) was
washed with saturated aqueous sodium bicarbonate followed by brine.
The organic fraction was dried (MgSO.sub.4) and concentrated to
give a crude product as a white foam. The crude material was
partially purified by silica gel column chromatography (eluted with
10% CH.sub.3CN in CH.sub.2Cl.sub.2) to afford 1.45 g of a mixture
of 2-O-(benzyloxycarbonyl)-7-deoxy-7.alpha.-fl- uoropaclitaxel and
2'-O-(benzyloxycarbonyl)-8-desmethyl-7,8-cyclopropapacl- itaxel
(82:18 mixture by .sup.1H-NMR).
[0159] The above mixture (1.45 g) was taken up in ethyl acetate (60
mL) and treated with palladium on carbon (300 mg). After shaking
for 4 h under 50 pounds per square inch (psi) of hydrogen, the
reaction was vented and filtered through a short plug of silica gel
and concentrated. This furnished the desired product mixture,
7-deoxy-7.alpha.-fluoropaclit- axel and
8-desmethyl-7,8-cyclopropapaclitaxel, as a white foam (1.24 g, Y:
99%, 90:10 mixture by .sup.1H-NMR). This mixture was taken up in
dry methylene chloride (30 mL) and treated with tetrabutylammonium
borohydride (745 mg, 2.9 mmol, 2 eq) and allowed to stir for 6 h.
The reaction was then quenched with acetic acid (1 mL), diluted
with additional methylene chloride (30 mL) and washed with
saturated aqueous sodium bicarbonate solution. The organic fraction
was dried (MgSO.sub.4) and concentrated. The crude, substituted
taxane core mixture was partially purified by silica gel column
chromatography (eluted with 10% CH.sub.3CN in CH.sub.2Cl.sub.2) to
give a 90:10 mixture (as determined by .sup.1H-NMR) of
7-deoxy-7-.alpha.-fluorobaccatin III and
8-desmethyl-7,8-cyclopropabaccatin III (510 mg, 60%) as a white
foam. The resulting foam was crystallized from hot isopropanol to
give 7-deoxy-7.alpha.-fluorobaccatin III (as small white needles
(Y: 410 mg); m.p. 234-236.degree. C. (decomposition).
[0160] Preparation 4.
10-Desacetoxy-7-deoxy-7.alpha.-fluoropaclitaxel 27
[0161] (a) 2'-O-Benzyloxycarbonyl-10-desacetoxypaclitaxel
[0162] 10-Desacetoxypaclitaxel (27 mg, 0.034 mmol) in
dichloromethane (1 mL) was treated with benzyl chloroformate
(0.0146 mL, 0.102 mmol), followed by diisopropylethylamine (0.0177
mL, 0.102 mmol). The reaction mixture was stirred at 0.degree. C.
for 45 min, and at rt for 12 h. Evaporation of the solvent and
silica gel chromatography (being eluted with 40% ethyl acetate in
hexane) gave 25.5 mg (Y: 81%) of the title compound as a foam.
[0163] (b) 10-Desacetoxy-7-deoxy-7.alpha.-fluoropaclitaxel
[0164] The product obtained in Step (a) (25.5 mg, 0.028 mmol) in
dichloromethane (0.8 mL) at 0.degree. C. was treated with DAST
(0.0071 mL, 0.055 mmol). After 45 min at 0.degree. C., the reaction
was allowed to proceed for 5 h at rt. Evaporation of the solvent
and chromatography gave
2'-O-benzyloxycarbonyl-7-deoxy-7.alpha.-fluoropaclitaxel as a crude
foam. This compound was dissolved in ethyl acetate (1 mL) and was
stirred under slightly over one atmosphere of hydrogen in the
presence of palladium on charcoal (10%, 8.9 mg) for 12 h at rt. The
catalyst was removed by filtration and silica gel chromatography of
the product gave 10 mg (Y: 40% over two steps) of the title product
as a foam.
[0165] Preparation 5. 10-Deacetyl-7-deoxy-7.alpha.-fluoropaclitaxel
28
[0166] A solution of
2',10-O-bis(2,2,2-trichloroethoxycarbonyl)-10-deacety- lpaclitaxel
(120 mg, 0.103 mmol) in dichloromethane (2 mL) was cooled at
0.degree. C. and treated with DAST (0.0266 mL, 0.207 mmol). The
solution was stirred at 0.degree. C. for 30 min and at rt for 4 h.
The reaction was quenched by adding water (0.05 mL). The reaction
mixture was concentrated and the residue was purified by silica gel
chromatography (being eluted with 30% ethyl acetate in hexane) to
afford 81 mg (Y: 68%) of
2',10-O-bis(2,2,2-trichloroethoxycarbonyl)-7-deoxy-7.alpha.-fluoropacl-
itaxel as a foam. This compound (63 mg, 0.054 mmol) was dissolved
in methanol (0.5 mL) and acetic acid (0.5 mL) and treated with zinc
dust (104 mg, 1.62 mmol) for 90 min at 45.degree. C. The reaction
mixture was filtered and the filtrate was concentrated. Silica gel
chromatography (being eluted with 40% hexane in 60% ethyl acetate)
of the residue afforded 38 mg (Y: 86%) of the title compound as a
white solid.
[0167] Preparation 6. 7-Deoxybaccatin III 29
[0168] (a) 7-O-[(Methylthio)thiocarbonyl]baccatin III
[0169] Baccatin III (750 mg, 1.278 mmol) was dissolved in dry
tetrahydrofuran (20 mL) and imidazole (8.7 mg, 0.128 mmol) was
added in one lot. Sodium hydride (50% in mineral oil, 77 mg, 1.597
mmol) was added at room temperature. When gas evolution had ceased
(10 min), carbon disulfide (4.6 mL) was added at once. After 3 h at
room temperature, the yellow solution was treated with methyl
iodide (0.238 mL, 3.835 mmol) and stirred overnight. Work-up with
ethyl acetate and water gave the title compound as a crude oil.
[0170] Alternate Run:
[0171] Baccatin III (394 mg, 0.672 mmol) was dissolved in
tetrahydrofuran (5 mL) and carbon disulfide (1 mL). To this
solution was added sodium hydride (40.3 mg, 60%, 1.009 mmol). A
catalytic amount of imidazole was also added. The reaction mixture
was stirred at room temperature for 1.5 h. and then methyl iodide
(122.8 .mu.L, 2.016 mmol) was added. After 40 min, the solvent was
removed in vacuo, and the residue was chromatographed on silica gel
(eluted with 20%-50%-60% ethyl acetate in hexanes) to afford the
title product (260 mg, Y: 57.2%) together with 7-epi baccatin (98.5
mg, 25%).
[0172] (b)
7-O-[(Methylthio)thiocarbonyl]-13-O-triethylsilylbaccatin III
[0173] The product of step (a) as a crude oil was dissolved in dry
dimethylformamide (5 mL) and treated with imidazole (870 mg, 12.78
mmol) and triethylsilyl chloride (2.10 mL, 12.78 mmol) at room
temperature for 15 h. Addition of water was followed by extraction
into ethyl acetate. The organic layer was washed extensively with
water, and then dried. Silica gel flash chromatography (being
eluted with 20% ethyl acetate in hexanes) gave the title compound
as a glassy solid (Y: 209 mg, 20% yield over two steps).
[0174] Alternate Run:
[0175] The product of step (a) (193.4 mg, 0.286 mmol) was dissolved
in dry dimethylformamide (2.86 mL). To this solution was added
imidazole (77.9 mg, 1.14 mmol), followed by triethylsilyl chloride
(192 .mu.L, 1.14 mmol). The reaction mixture was stirred overnight
at room temperature. After 12 h, the reaction mixture was diluted
with ethyl acetate (150 mL). The organic layer was washed with
water (3.times.10 mL) and brine (1.times.10 mL), dried, and
concentrated in vacuo. The residue was chromatographed on silica
gel (eluted with 20% Ethyl acetate in hexanes) to afford the title
product (163 mg,Y: 72.0%).
[0176] (c) 7-Deoxy-13-O-triethylsilylbaccatin III
[0177] The product of step (b) (182 mg, 0.230 mmol) in dry benzene
(5 mL) was heated to 80.degree. C. in the presence of tributyltin
hydride (0.310 mL, 1.150 mmol) and 2,2'-azobisisobutyronitrile
(AIBN, 10 mg). After 3 h the solution was allowed to cool, and the
solvent evaporated in vacuo. Silica gel chromatography of the
residue (being eluted with 20% ethyl acetate in hexane) gave the
title compound as an oil.
[0178] (d) 7-Deoxybaccatin III
[0179] The product of step (c) was dissolved in tetrahydrofuran (5
mL) and treated with tetrabutylammonium fluoride (1M in
tetrahydrofuran, 0.50 mL, 0.50 mmol) for 2 h at room temperature.
Dilution with ethyl acetate and washing with water and brine,
followed by silica gel chromatography (being eluted with 1:1 ethyl
acetate/hexane) gave the title compound as a white glassy solid (63
mg, Y: 58% over two steps).
[0180] Preparation 7. 10-Desacetoxybaccatin III 30
[0181] (a)
10-Deacetyl-10-O-(pentafluorophenoxy)thiocarbonyl-7-O-triethyls-
ilylbaccatin III
[0182] 7-O-Triethylsilyl-10-deacetylbaccatin III (see Greene et al,
J. Am. Chem. Soc., 110, p. 5917, 1988) (319 mg, 0.485 mmol) was
dissolved in dry tetrahydrofuran (5 mL), cooled to -40.degree. C.,
and treated with n-butyllithium (1.58M in hexanes, 0.384 mL, 0.606
mmol). After 40 min at this temperature, pentafluorophenyl
chlorothionoformate (0.086 mL, 0.536 mmol) was added neat by
syringe. The reaction mixture was stirred at -20.degree. C. for 90
min, quenched with saturated ammonium chloride solution, and
extracted with ethyl acetate. The ethyl acetate layer was dried and
concentrated. The residue was purified by silica gel chromatography
(being eluted with 40% ethyl acetate in hexane) to afford the title
compound as a foam (320 mg, Y: 74%).
[0183] (b) 10-Desacetoxy-7-O-triethylsilylbacctain III
[0184] The product of step (a) (119 mg, 0.135 mmol) was dissolved
in dry toluene (3 mL) and treated with AIBN (2 mg). The solution
was degassed with dry nitrogen, then tributyltin hydride (0.055 mL,
0.202 mmol) was added. Subsequently, the solution was heated at
90.degree. C. for 1 h. The solvent was then evaporated and silica
gel chromatography of the residue (being eluted with 40% ethyl
acetate in hexane) gave the title compound (87 mg, Y: 99%) as a
colorless foam.
[0185] (c) 10-Desacetoxybaccatin III
[0186] The product of step (b) (120 mg, 0.187 mmol) was dissolved
in acetonitrile (3.5 mL) and the solution was cooled to -10.degree.
C. Concentrated HCl (36%, 0.060 mL) was added, and the solution was
stirred for 30 min. The mixture was diluted with ethyl acetate (75
mL), and washed with saturated aqueous sodium bicarbonate and
brine, then dried and concentrated. The residue was purified by
flash silica chromatography (being eluted with 70% ethyl acetate in
hexane) to afford 10-deacetyloxybaccatin III as a foam (75 mg, Y:
76%).
[0187] Preparation 8. 10-Desacetoxy-7-deoxybaccatin III 31
[0188] (a) 7-O-[(Methylthio)thiocarbonyl]-10-desacetoxybaccatin
III
[0189] 10-Desacetoxybaccatin III (75 mg, 0.142 mmol) was dissolved
in dry tetrahydrofuran (2 mL) and carbon disulfide (0.5 mL). Sodium
hydride (60% in mineral oil, 8.5 mg, 0.213 mmol) was then added,
and the mixture was stirred at room temperature for 2 h.
Iodomethane (0.026 mL, 0.426-mmol) was added, and the reaction was
allowed to proceed overnight. The solvent was then removed and the
residue was purified by silica gel chromatography (being eluted
with 50-70% ethyl acetate in hexane) to give the title compound as
a foam (46.4 mg, Y: 53%).
[0190] (b) 10-desacetoxy-7-deoxy-baccatin III
[0191] The product of step (a) (36 mg, 0.058 mmol) was refluxed in
benzene (1 mL) in the presence of AIBN (2 mg) and tributyltin
hydride (0.079 mL, 0.290 mmol) under an argon atmosphere for 3 h.
Concentration of the reaction mixture and flash silica gel
chromatography of the residue (being eluted with 40% ethyl acetate
in hexanes) followed by HPLC (high pressure liquid chromatography)
separation from other components afforded the title compound as a
foam (16.8 mg, Y: 56%).
[0192] Alternate Run:
[0193] To a solution of
7-O-[(methylthio)carbonothioyl]-13-O-triethylsilyl- baccatin III
(product of preparation I, step (b), 416.3 mg, 0.527 mmol) in dry
toluene (10.5 mL) was added catalytic amount of AIBN, and the
resulting solution was degassed with dry N.sub.2 for 5 min.
Tributyltin hydride (708.7 uL, 2.63 mmol) was the added and the
reaction mixture was heated at 100.degree. C. for 2 h., after which
another portion of tributyltin hydride (425.3 uL, 1.581 mmol) was
added. The reaction mixture was heated for 5.5 h at 100.degree. C.,
and then allowed to cool to room temperature. Silica gel
chromatography (eluted with 20% ethyl acetate in hexanes) afforded
7-deoxy-10-desacetoxy-13-O-(triethysilyl)bac- catin III (320 mg, Y:
97%).
[0194] To a solution of the product of the above step (160 mg,
0.255 mmol) in dry tetrahydrofuran (2 mL) at room temperature was
added tetrabutylammonium fluoride (766 uL, 1M, 0.766 mmol). The
reaction mixture was stirred for 1 h at room temperature. The
solvent was removed and the residue was chromatographed on silica
gel (eluted with 50-70% ethyl acetate in hexanes) to afford the
desired title product (115 mg, Y: 87.9%).
[0195] Preparation 9. (3R,
4S)-1-t-Butoxycarbonyl-4-phenyl-3-triethylsilyl- oxy-2-azetidinone
32
[0196] To a stirred solution of
(3R,4S)-4-phenyl-3-triethylsilyloxy-2-azet- idinone (2.200 g, 7.92
mmol) in dry tetrahydrofuran (25 mL) was added
N,N-diisopropylethylamine (1.65 mL. 9.510 mmol, 1.2 equiv) at
0.degree. C. under an argon atmosphere. The solution was stirred
for 5 min followed by the addition of di-t-butyl dicarbonate (2.080
g, 9.510 mmol, 1.2 equiv) and 4-dimethylaminopyridine (193.6 mg,
1.581 mmol, 0.20 equiv). The reaction mixture was stirred at
0.degree. C. for 60 min., then diluted with ethyl acetate (25 mL).
The resulting solution was washed with brine, 10% NaHCO.sub.3, 10%
HCl solution, dried (MgSO.sub.4), and concentrated to give a crude
compound (oil). The compound was further purified by silica gel
flash chromatography (being eluted with 15% ethyl acetate in
hexanes) to afford the title compound as a white solid (2.4 g, Y:
83%).
[0197] Preparation 10.
(.+-.)-cis-3-Acetyloxy-4-phenylazetidin-2-one 33
[0198] (a) To a 1 L, 3-necked round bottom flask equipped with a
thermometer, magnetic stirrer and dropping funnel was added
hydrobenzamide (30.00 g, 100.5 mmol) and ethyl acetate (150 mL).
With stirring and under a blanket of argon, the reaction mixture
was cooled to 5.degree. C. and triethylamine (16.8 mL, 121 mmol)
was added. A solution of acetoxyacetyl chloride (12.4 mL, 116 mmol)
in ethyl acetate (300 mL) was then added dropwise over a 90 min
period. After 16 h at this temperature, the reaction mixture was
allowed to warm to 20.degree. C. (1.5 h) and transferred to a
separatory funnel. The organic layer was washed successively with
aqueous NH.sub.4Cl (sat) (150 mL, 100 mL), aqueous NaHCO.sub.3
(saturated) (120 mL) and brine (120 mL). For purposes of
characterization, the title compound can be isolated at this stage
by drying the organic phase over MgSO.sub.4, filtering, and
removing the solvent in vacuo. This provided
(.+-.)-cis-3-acetyloxy-1-[(phenyl)(benzyl-
idenimino)methyl]-4-phenylazetidin-2-one in quantitative crude
yield as a red glass.
[0199] (b) A solution of the compound obtained in part (a) in ethyl
acetate (500 mL) was carefully transferred, under a stream of
argon, to a 2.0 L Parr flask containing 10% palladium on activated
charcoal (6.00 g). This mixture was treated with hydrogen (4 atm)
for 20 h whereupon the catalyst was removed by filtration through a
pad of Celite. The filter cake was slurried in ethyl acetate (200
mL), stirred (10 min) and filtered. The filter cake was rinsed with
ethyl acetate (100 mL) and the filtrates combined. The organic
layer was washed with 10% HCl (300 mL) and both layers filtered
through a sintered glass funnel to remove the white precipitate
(dibenzylamine.cndot.HCl) which was rinsed with ethyl acetate (100
mL). The phases were separated and the organic layer was washed
with another portion of 10% HCl (200 mL). The combined 10% HCl
washes were re-extracted with ethyl acetate (200 mL) and the
combined organic layers were washed with aqueous NaHCO.sub.3
(saturated) (300 mL) and brine (250 mL). The organic layer was
dried over MgSO.sub.4, filtered and concentrated in vacuo to a
final volume of 75 mL. This mixture was cooled to 4.degree. C. and
the precipitated product isolated by filtration. The filter cake
was washed with hexane (200 mL) to provide 16.12 g (78.1% overall
yield from hydrobenzamide) of the title compound as white
needles.
[0200] mp=150-151.degree. C.
[0201] Preparation 11. (.+-.)-
cis-3-Triethylsilyloxy-4-(2-furyl)-N-t-buto-
xycarbonylazetidin-2-one 34
[0202] (a) The procedure described in Preparation 10, part (a), was
followed except that hydrofuramide [i.e.
2-furyl-CH-(N.dbd.CH-2-furyl).su- b.2] was used instead of
hydrobenzamide and the reaction was performed on 18.6 mmol (vs 100
mmol) scale. Thus, hydrofuramide (5.00 g, 18.6 mmol), triethylamine
(3.11 mL, 22.3 mmol) and acetoxyacetyl chloride (2.30 mL, 21.4
mmol) gave 6.192 g (Y: 90.4%) of
(.+-.)-cis-3-acetyloxy-1-[(2-furyl)-
(2-furylmethylenimino)methyl]-4-(2-furyl)azetidin-2-one as a pale
red syrup.
[0203] (b) The procedure described in Preparation 10, part (b), was
followed except that the product was isolated by preparative TLC
and the reaction was performed on the 2.7 mmol scale based on the
original amount of hydrofuramide. Thus, the crude product obtained
in part (a) above was re-dissolved in ethyl acetate (50 mL) and
added to 10% palladium on activated charcoal (150 mg). Purification
of the crude solid by preparative TLC (2 mm silica gel, eluted with
1:1 ethyl acetate/hexane) gave 386 mg (65.8% corrected overall
yield from hydrofuramide)
(.+-.)-cis-3-(acetyloxy)-4-(2-furyl)azetidin-2-one as a yellow
solid. This was recrystallized from ethyl acetate/hexane.
[0204] mp=118-119.degree. C.
[0205] (c) The compound obtained in part (b) above (3.78 g, 19.4
mmol) in 60 mL of methanol was stirred with K.sub.2CO.sub.3 (20 mg,
0.14 mmol) for 90 min and the solution neutralized with Dowex
50W-X8 and filtered. The filtrate was concentrated and the residue
dissolved in 80 mL of anhydrous THF and stirred at 0.degree. C.
with imidazole (1.44 g, 21.2 mmol) and TESCl (3.4 mL, 20.2 mmol)
for 30 min. The solution was diluted with ethyl acetate and washed
with brine, dried over MgSO.sub.4 and concentrated. The residue was
chromatographed over silica gel (eluted with 3:1 hexane/ethyl
acetate) to give 4.47 g (Y: 86%) of (.+-.)-
cis-3-triethylsilyloxy-4-(2-furyl)-azetidin-2-one as a colorless
oil.
[0206] (d) The product of part (c) (2.05 g, 7.7 mmol) in 30 mL of
dichloromethane was stirred at 0.degree. C. with diisopropylethyl
amine (1.5 mL, 8.6 mmol) and di-t-butyl dicarbonate (2.0 g, 9.2
mmol) in addition to a catalytic amount of dimethylaminopyridine
(DMAP). The solution was diluted with dichloromethane and washed
with brine, dried over MgSO.sub.4 and concentrated. The residue was
chromatographed over silica gel (eluted with 8:1 hexane/ethyl
acetate) to give 2.0 (Y: 70%) of the title compound as a waxy
solid.
[0207] The racemic mixture obtained in part (b) may be used as
substrate for enzymatic hydrolysis using a lipase such as PS-30
from Pseudomonas sp. (Amano International Co.) to give
(3R,4R)-3-hydroxy-4-(2-furyl)-azeti- din-2-one. The method of
enzymatic resolution using the lipase PD-30 and other enzymes is
disclosed in our co-pending application U.S. Ser. No. 092,170,
filed Jul. 14, 1993 which is hereby incorporated by reference in
its entirety.
[0208] The procedure in parts (c) and (d) was followed using
(3R,4R)-3-hydroxy-4-(2-furyl)-azetidin-2-one to provide
(3R,4R)-N-(t-butoxycarbonyl)-3-triethylsilyoxy-4-(2-furyl)azetidine-2-one-
.
[0209] Preparation 12. (.+-.)-
cis-3-Triethylsilyloxy-4-(2-thienyl)-N-t-bu-
toxycarbonylazetidin-2-one 35
[0210] (a) The procedure described in Preparation 10, step (a) was
followed except that hydrothienamide [i.e.
2-thienyl-CH-(N.dbd.CH-2-thien- yl).sub.2] was used instead of
hydrobenzamide. Thus, hydrothienamide (30 g, 94.7 mmol),
thiethylamine (15.84 mL, 114 mmol) and acetoxyacetyl chloride (11.6
mL, 108 mmol) provided (.+-.)-cis-3-acetyloxy-1-[(2-thieny-
l)(2-trienylmethylenimino)methyl]-4-(2-thienyl)azetidin-2-one as
viscous oil.
[0211] (b) A 70% aqueous solution of acetic acid (0.35 mL glacial
acetic acid and 0.15 mL water) was added in one portion to a
stirred solution of the product obtained in part (a) (0.431 g, 1.03
mmol) in dichloromethane (2.93 ml) at 25.degree. C. The reaction
mixture was brought to reflux and stirred for 2.5 h. The reaction
was diluted with 50 mL dichloromethane and then washed with two 75
mL portions of saturated aqueous sodium bicarbonate and then one 50
mL portion of saturated brine. The organic extract was concentrated
in vacuo to a brown oil, dissolved in a minimal amount of
dichloromethane, and then placed on a silica gel column measuring
4" by 0.5". Elution using a gradient of 10 through 60% EtOAc in
hexane provided less polar sideproducts and then
(.+-.)-cis-3-acetyloxy-4- -(2-thienyl)azetidin-2-one (0.154 g, Y:
75%) as a white solid.
[0212] (c) A solution of the product obtained in part (b) (2.5 g,
11.8 mmol) was dissolved in methanol (10 mL) and treated with
saturated aqueous sodium bicarbonate (10 mL) and the resulting
slurry was allowed to stir at ambient temperature for 3 h. The
reaction was then diluted with ethyl acetate (20 mL) and washed
with water (15 mL). The aqueous fraction was back extracted several
times with ethyl acetate and the combined organic fractions were
dried (MgSO.sub.4) and concentrated to give a yellow solid (Y: 1.7
g). The crude material was dissolved in dry tetrahydrofuran (20 mL)
and the solution was cooled to 5.degree. C. in an ice/water bath.
Imidazole (752 mg, 1.1 eq) was then added. After stirring 5 min,
triethylchlorosilane (1.85 mL, 1.1 eq) was added dropwise. The
resulting suspension was allowed to stir for 3 h at that
temperature; then the solids were removed by filtration. The
organic fraction was washed with water (2.times.20 mL) then dried
(MgSO.sub.4) and concentrated. The crude product was purified by
silica gel column chromatography (eluted with hexanes/ethyl acetate
7:3) to give
(.+-.)-cis-3-triethylsilyloxy-4-(2-thienyl)-azetidin-2-one as a
colorless solid (1.5 g, Y: 45%). m.p. 70-71.degree. C.
[0213] Alternate Run:
[0214] The product obtained in part (b) (2.0 g, 9.37 mmol) in 40 mL
of methanol was stirred with K.sub.2CO.sub.3 (60 mg, 0.43 mmol) for
30 min and the solution neutralized with Dowex 50W-X8 and filtered.
The filtrate was concentrated and the residue dissolved in 50 mL of
anhydrous THF and stirred at 0.degree. C. with imidazole (0.85 g,
11.3 mmol) and TESCl (1.9 mL, 12.5 mmol) for 30 min. The solution
was diluted with ethyl acetate and washed with brine, dried over
MgSO.sub.4 and concentrated. The residue was chromatographed over
silica gel (eluted with 3:1 hexane/ethyl acetate) to give 2.13 g
(Y: 86%) of the title product as a colorless oil.
[0215] (d) A solution of the product obtained in part (c) (425.7
mg, 1.48 mmol) was dissolved in dichloromethane (10 mL) and cooled
to 5.degree. C. in an ice/water bath. The reaction was treated with
a catalytic amount of DMAP followed by diisopropylethylamine
(TESCl, 0.25 mL, 1.0 eq) then by di-t-butyl dicarbonate (388.4 mg,
1.2 eq). After stirring 2 h at that temperature the reaction was
quenched with saturated aqueous sodium bicarbonate (5 mL) and the
organic fraction was washed with water (5 mL) then dried
(MgSO.sub.4), passed through a short plug of silica gel and
concentrated to give the desired product as a colorless oil (525.3
mg, Y: 93%).
[0216] Prepartion 13. (3R,
4R)-3-Triethylsilyloxy-4-(2-furyl)-N-n-butyloxy-
carbonylazetidin-2-one 36
[0217] (3R,4R)-3-Triethylsilyloxy-4-(2-furyl)azetidin-2-one (0.58
g, 2.17 mmol) in 30 mL of dichloromethane was stirred with
diisopropylethyl amine (0.4 mL, 2.30 mmol) and butylchloroformate
(0.3 mL, 2.36 mmol) in addition to a catalytic amount of DMAP. The
solution was stirred for 1 h and diluted with dichloromethane and
washed with brine, dried over MgSO.sub.4 and concentrated. The
residue was chromatographed over silica gel (eluted with 3:1
hexane/ethyl acetate) to give 523 mg of product (Y: 65%); IR(KBr)
1820, 1734, 1318, 1018, 734 cm.sup.-1; .sup.1H-NMR (CDCl.sub.3, 300
MHz) .delta. 7.38 (m, 1H), 6.35 (m, 2H), 5.09 (ABq, J=15.5, 5.6 Hz,
2H), 4.14 (m, 2H), 1.56 (m, 2H), 1.28 (s, 2H), 0.87 (t, J=8.7 Hz,
3H), 0.82 (t, J=7.9, 9H), 0.50 (m, 6H); .sup.13C-NMR (CDCl.sub.3,
75.5 Hz) .delta. 165.4, 149.1, 147.6, 142.9, 110.5, 109.9, 77.7,
66.6, 55.9, 30.5, 18.8, 13.6, 6.3, 4.3; DCIMS M+H calcd for
C.sub.18H.sub.29NO.sub.5Si: 368, Found: 368.
[0218] Preparation 14.
(3R,4R)-3-Triethylsilyloxy-4-(2-furyl)-N-isopropylo-
xycarbonylazetidin-2-one 37
[0219] (3R, 4R) -3-Triethylsilyloxy-4-(2-furyl)azetidin-2-one (0.51
g, 1.91 mmol) in 25 mL of dichloromethane was stirred with
diisopropylethyl amine (0.78 mL, 4.4 mmol) and
i-propylchloroformate (4.0 mL, 1.0M in toluene, 4.0 mmol) in
addition to a catalytic amount of DMAP. The solution was stirred
for 1 h and diluted with dichloromethane and washed with brine,
dried over MgSO.sub.4 and concentrated. The residue was
chromatographed over silica gel (eluted with 5:1 hexane/ethyl
acetate) to give 649 mg of the title product (Y: 96%); IR(KBr)
1822, 1812, 1716, 1374, 1314, 1186, 1018, 1004, 746 cm.sup.-1;
.sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta. 7.39 (m, 1H), 6.35 (m,
2H), 5.08 (ABq, J=15.6, 5.6 Hz, 2H), 4.96 (d, J=10.0 Hz, 1H), 1.25
(d, J=6.3 Hz, 3H), 1.17 (d, J=6.3 Hz, 3H)), 0.83 (t, J=7.8, 9H),
0.50 (m, 6H); .sup.13C-NMR (CDCl.sub.3, 75.5 Hz) .delta. 165.5,
148.6, 147.8, 142.9, 110.5, 109.9, 77.6, 71.1, 55.9, 21.7, 21.6,
6.3, 4.4; DCIMS M+H calcd for C.sub.17H.sub.28NO.sub.5Si: 354,
Found: 354.
[0220] Preparation 15.
(.+-.)-cis-3-Triethylsilyloxy-4-isobutenyl-N-t-buto-
xycarbonylazetidin-2-one
[0221] (a) N-4-methoxy-N-(3-methyl-2-butenyl)benzenamine 38
[0222] A solution of p-anisidine (5.7 g, 46.3 mmol) was dissolved
in diethylether (100 mL) and was treated with a catalytic amount of
p-toluensulfonic acid (10 mg). To this was added 3-methyl-2-butenal
(2.67 mL, 50.9 mmol) in one portion and the reaction was allowed to
stir at ambient temperature for 16 h. The solvent was then
evaporated on a rotary evaporator at 0.5 torr to furnish the
desired imine (8.7 g, 100%) as a brown oil; .sup.1H NMR 300 MHz,
CDCl.sub.3): .delta. 8.38 (d, 1H, J=9.5 Hz), 7.11 (dd, 2H, J=2.2,
6.7 Hz), 6.88 (dd, 2H, J=2.2, 6.7 Hz), 6.22-6.18 (m, 1H), 3.81 (s,
3H), 2.01 (s, 3H), 1.95 (s, 3H).
[0223] (b)
(.+-.)-cis-N-(4-methoxyphenyl)-3-acetyloxy-4-isobutenylazetidin-
-2-one 39
[0224] A solution of acetoxyacetyl chloride (6.9 g, 50.5 mmol) was
dissolved in ethyl acetate (100 mL) and cooled to -30.degree. C.
under an inert atmosphere. To this solution was added triethylamine
(7.0 mL, 50.5 mmol) over a 5 min period. The resulting white slurry
was then treated with an ethyl acetate solution of
N-4-methoxy-N-(3-methyl-2-butenyl)benze- namine (8.7 g, 40 mL)
dropwise over a 20 min period. The resulting green-brown slurry was
then gradually allowed to warm to ambient temperature over a 4 h
period. The slurry was then filtered through a pad of celite and
the filtrate was washed with water then brine. The organic fraction
was dried (MgSO.sub.4) and concentrated to give a brown oil. The
crude product was purified by careful silica gel chromatography
(eluted with hexanes/ethyl acetate 8:2) to furnish an orange oil
which solidified on standing. This was recrystallized from
dichloromethane/hexanes to furnish the desired product as a pale
yellow solid (4.4 g, 32%); .sup.1H NMR (300 MHz, CDCl.sub.3):
.delta. 7.32 (d, 2H, J=9.1 Hz), 6.86 (d, 2H, J=9.1 Hz), 5.59 (dd,
1H, J=3.0, 7.8 Hz), 5.14-5.10 (m, 1H), 4.96 (dd, 1H, J=4.8, 9.3
Hz), 3.77 (s, 3H), 2.11 (s, 3H,), 1.81 (s, 3H), 1.78 (s, 3H).
[0225] (c) (.+-.)-cis-3-Acetyloxy-4-isobutenylazetidin-2-one 40
[0226] A solution of the
(.+-.)-cis-N-(4-methoxyphenyl)-3-acetyloxy-4-isob-
utenylazetidin-2-one (4.88 g, 16.2 mmol) was dissolved in
acetonitrile (50 mL) and cooled to 0-5.degree. C. in an ice bath.
To this was added a cold solution of ceric ammonium nitrate (26.6
g, 48.6 mmol, 50 mL) in one portion. The deep red reaction was
allowed to stir for 10 min and during that time the color gradually
lightened to orange. The cold solution was transferred to a
separatory funnel, diluted with water, and extracted with ethyl
acetate. The organic fraction was washed with several portions of
10% aqueous sodium sulfite, followed by saturated aqueous sodium
bicarbonate. The organic fraction was dried (MgSO.sub.4) and
concentrated to give the desired product (2.71 g, 91%) as a
yellow-orange solid that was used directly in the next step;
.sup.1H NMR (300 MHz, CDCl.sub.3): .delta. 6.11 (bs, 1H), 5.73 (dd,
1H, J=2.2, 4.7 Hz), 5.12-5.08 (m, 1H), 4.63 (dd, 1H, 4.7, 9.1 Hz),
2.09 (s, 3H), 1.75 (s, 3H), 1.67 (s, 3H).
[0227] (d) (.+-.)-cis-3-Triethylsilyloxy-4-isobutenylazetidin-2-one
41
[0228] (.+-.)-cis-3-Acetyloxy-4-isobutenylazetidin-2-one (1.47 g,
8.0 mmol) was dissolved in methanol (15 mL) and was stirred with
K.sub.2CO.sub.3 (110.5 mg, 0.8 mmol) for 3 h at ambient
temperature. The solution was then neutralized with Dowex
50W-X8resin and then filtered. The filtrate was concentrated and
the crude solid was dissolved in THF (25 mL) and cooled to
5.degree. C. in an ice bath. Imidazole (544.0 mg, 8.0 mmol) was
added and once dissolved, triethylsilyl chloride (1.34 mL, 8.0
mmol) was added dropwise via syringe. The resulting slurry was
allowed to warm to ambient temperature and stir overnight. The
solution was filtered and the filtrate was washed with water, then
brine. The organic fraction was dried (MgSO.sub.4) and
concentrated. The crude solid was purified by silica gel
chromatography (eluted with hexanes/ethyl acetate 3:1) to furnish
the desired product (612 mg, 30%) as a pale yellow solid; .sup.1H
NMR (300 MHz, CDCl.sub.3): .delta. 5.87. (bs, 1H), 5.31-5.26 (m,
1H), 4.90 (dd, 1H, J=2.2, 4.7 Hz), 4.42 (dd, 1H, J=4.7, 9.3 Hz),
1.74 (s, 3H), 1.28 (s, 3H), 0.98-0.91 (m, 9H), 0.71-0.55 (m,
6H).
[0229] (e)
(.+-.)-cis-3-Triethylsilyloxy-4-isobutenyl-N-t-butoxycarbonylaz-
etidin-2-one 42
[0230] (.+-.)-cis-3-Triethylsilyloxy-4-isobutenylazetidin-2-one
(1.01 g, 3.95 mmol) was dissolved in dichloromethane (20 mL) and
was treated with diisopropylethylamine (0.68 mL, 3.95 mmol) and a
catalytic amount of dimethylaminopyridine. To this solution was
added di-t-butyl dicarbonate (1.02 g, 4.68 mmol) and the solution
was allowed to stir for 24 h at ambient temperature. The solution
was then diluted with additional dichloromethane and washed with
water then brine. The organic fraction was dried (MgSO.sub.4) and
concentrated. The residue was purified by silica gel chromatography
(eluted with hexanes/ethyl acetate 8:2) to give the desired product
(1.26 g, 90%) as a colorless oil; .sup.1H NMR (300 MHz,
CDCl.sub.3): .delta. 5.24 (d, 1H, J=9.6 Hz), 4.86 (d, 1H, J=5.7
Hz), 4.72 (dd, 1H, J=6.0, 9.9 Hz), 1.78 (d, 3H, J=1.1 Hz), 1.75 (d,
3H, J=1.1 Hz), 1.47 (s, 9H), 0.96-0.91 (m, 9H), 0.64-0.55 (m,
6H).
[0231] The procedure described above in Preparations 9, 11(d),
12(d), 13, 14, and 15(e) may be adapted to the preparation of other
N-substituted azetidinones useful in the preparation of compounds
of the invention. Examples of such azetidinones are listed in the
following table; P below is a hydroxy protecting group such as
triethyl silyl, triisopropylsilyl and ethoxyethyl.
5 43 L R.sup.4(O).sub.p R.sup.5 Cl Ph 4-CH.sub.3O--Ph--
3,4-diCH.sub.3O--Ph-- Ph-- 4-F--Ph-- 4-CF.sub.3--Ph-- 2-furanyl-
2-thienyl- PhCH.dbd.CH-- 2-furanyl-CH.dbd.CH--
(CH.sub.3).sub.2CHCH.sub.2-- C.sub.6H.sub.11--CH.sub.2--
(CH.sub.3).sub.2CH-- PhCH.sub.2CH.sub.2--
C.sub.6H.sub.11--CH.sub.2CH.sub.2-- CH.sub.3CH.sub.2CH.sub.2--
4-Cl--Ph 2-F--Ph 3-F--Ph 4-CH.sub.3--Ph (CH.sub.3).sub.2C.dbd.CH Cl
4-CH.sub.3O--Ph-- 3,4-diCH.sub.3O--Ph-- 4-CF.sub.3--Ph-- 2-furanyl-
PhCH.dbd.OH-- (CH.sub.3).sub.2CHCH.sub.2--
C.sub.6H.sub.11--CH.sub.2-- PhCH.sub.2CH.sub.2--
(CH.sub.3).sub.3COCO.sub.2-- (CH.sub.3).sub.3CO-- 4-CH.sub.3O--Ph--
4-F--Ph-- 4-CF.sub.3--Ph-- PhCH.dbd.CH-- (CH.sub.3).sub.2CH--
PhCH.sub.2CH.sub.2-- C.sub.6H.sub.11--CH.sub.2CH.sub.2--
CH.sub.3CH.sub.2CH.sub.2-- Cl CH.sub.3-- 4-CH.sub.3O--Ph-- Ph--
4-F--Ph-- 2-furanyl- 2-furanyl-CH.dbd.CH-- PhCH.sub.2CH.sub.2--
C.sub.6H.sub.11--CH.sub.2CH.sub.2-- CH.sub.3CH.sub.2CH.sub.2--
[0232] Preparation 16. 10-deoxytaxotere 44
[0233] 10-Desacetoxy-7-O-triethylsilylbaccatin III (100 mg, 0.156
mmol) was placed in a flask under argon and dissolved in dry
tetrahydrofuran (1.5 mL). Upon cooling to -40.degree. C.,
n-butyllithium (1.45M in hexanes, 0.119 mL, 0.170 mmol) was added
dropwise, followed by
(3R,4S)-1-tert-butoxycarbonyl-4-phenyl-3-triethylsilyloxy-2-azetidinone
(94.2 mg, 0.25 mmol) in tetrahydrofuran (0.5 mL) over a period of 2
min. The mixture was immediately warmed to 0.degree. C. and stirred
for 45 min before being quenched with saturated ammonium chloride
(3 mL). The mixture was extracted with ethyl acetate, dried, and
concentrated. Silica gel chromatography (eluted with 30% ethyl
acetate in hexane) afforded
10-deoxy-2',7-bis-O-(triethylsilyl)taxotere as a foam (125 mg, Y:
76%). This compound (100 mg, 0.098 mmol) was immediately dissolved
in acetonitrile (2 mL) at -5.degree. C. and treated with
hydrochloric acid (0.037 mL, 36%, 12M). The mixture was stirred for
2 h at -5.degree. C., then quenched with aqueous bicarbonate,
extracted with ethyl acetate, and dried. Evaporation of the solvent
was followed by silica gel chromatography (eluted with 75% ethyl
acetate in hexane) to afford the title compound as a foam (80.5 mg,
Y: 80%).
[0234] The general procedure provided in Preparation 16 may be
adapted to the preparation of other compounds of formula (Ia) by
starting with the appropriate baccatin III component and the
azetidinone component; examples of other compounds of formula (Ia)
are listed in the following table. It will be understood that even
though the compounds below are shown with free hydroxy groups, with
the judicious selection of the various hydroxy protecting groups,
any one of the protecting groups at the 2'-, 7- or 10- position may
be selectively removed without affecting other protecting groups
present.
6 45 R.sup.2' R.sup.2a R.sup.3a R.sup.4(O).sub.p R.sup.5 H OH AcO
Ph 4-CH.sub.3O--Ph-- 3,4-diCH.sub.3O--Ph-- Ph-- 4-F--Ph--
4-CF.sub.3--Ph-- 2-furanyl- 2-thienyl- PhCH.dbd.CH--
2-furanyl-CH.dbd.CH-- (CH.sub.3).sub.2CHCH.sub.2--
C.sub.6H.sub.11--CH.sub.2-- (CH.sub.3).sub.2CH--
PhCH.sub.2CH.sub.2-- C.sub.6H.sub.11--CH.sub.2CH.sub.2--
CH.sub.3CH.sub.2CH.sub.2-- 4-Cl--Ph 2-F--Ph 3-F--Ph 4-CH.sub.3--Ph
H OH OH (CH.sub.3).sub.3CO 4-CH.sub.3O--Ph-- Ph 4-F--Ph--
4-CF.sub.3--Ph-- 2-furanyl- 2-thienyl- PhCH.dbd.CH--
C.sub.6H.sub.11--CH.sub.2-- (CH.sub.3).sub.2CH--
PhCH.sub.2CH.sub.2-- OH H Ph 4-CH.sub.3O--Ph--
3,4-diCH.sub.3O--Ph-- 4-F--Ph-- 4-CF.sub.3--Ph-- 2-furanyl-
2-thienyl- PhCH.dbd.CH-- 2-furanyl-CH.dbd.CH--
(CH.sub.3).sub.2CHCH.sub.2-- C.sub.6H.sub.11--CH.sub.2--
(CH.sub.3).sub.2CH-- PhCH.sub.2CH.sub.2--
C.sub.6H.sub.11--CH.sub.2CH.sub.2-- CH.sub.3CH.sub.2CH.sub.2-- H H
(CH.sub.3).sub.3CO 4-CH.sub.3O--Ph-- 3,4-diCH.sub.3O--Ph-- Ph--
4-F--Ph-- 4-CF.sub.3--Ph-- 2-furanyl- 2-thienyl- PhCH.dbd.CH--
2-furanyl-CH.dbd.CH-- (CH.sub.3).sub.2CHCH.sub.2--
C.sub.6H.sub.11--CH.sub.2-- - (CH.sub.3).sub.2CH--
PhCH.sub.2CH.sub.2-- C.sub.6H.sub.11--CH.sub.2CH.sub.2--
CH.sub.3CH.sub.2CH.sub.2- -- H OH AcO 2-naphthyl Ph 4-OH--Ph
4-CH.sub.3O--Ph 4-F--Ph (CH.sub.3).sub.3CO-- CH.sub.3--
(CH.sub.3).sub.2CH-- CH.sub.2.dbd.CHCH.sub.2-- 4-Cl--Ph F H AcO
(CH.sub.3).sub.3CO-- Ph F H OH Ph Ph H H AcO Ph 4-CH.sub.3O--Ph--
3,4-diCH.sub.3O--Ph-- Ph-- 4-F--Ph-- 4-CF.sub.3--Ph-- 2-furanyl-
2-thienyl- PhCH.dbd.CH-- 2-furanyl-CH.dbd.CH--
(CH.sub.3).sub.2CHCH.sub.2-- C.sub.6H.sub.11--CH.sub.2-- -
(CH.sub.3).sub.2CH-- PhCH.sub.2CH.sub.2--
C.sub.6H.sub.11--CH.sub.2CH.sub.2 CH.sub.3CH.sub.2CH.sub.2--
[0235] Preparation 17. Bis(methylthiomethyl)ether
CH.sub.3SCH.sub.2OCH.sub.2SCH.sub.3
[0236] Sodium iodide (8.23 g, 55.23 mmol) was added to a solution
of 1,1'-dichlorodimethyl ether (3.0 g, 26.3 mmol) in acetone (100
ml) at 0.degree. C. and the mixture was stirred at this temperature
for 20 min. Sodium thiomethoxide (1.84 g, 5.23 mmol) was then added
in four portions and the resulting solution was stirred for an
additional 1 h. The heterogeneous solution was then filtered
through a pad of celite and the filtrate concentrated in vacuo. The
residual oil was partitioned between ethyl acetate and saturated
aqueous sodium bicarbonate solution. The aqueous layer was removed
and further extracted with ethyl acetate. The combined organics
were then treated with a 1:1 (v:v) mixture of saturated aqueous
sodium bicarbonate and 5% aqueous sodium thiosulfate solution. The
organics were then washed with brine, dried over sodium sulfate and
concentrated in vacuo. The residual oil was purified via flash
chromatography (30:1, hexanes:ethyl acetate) to provide 1.9 g of a
yellow oil which was subsequently distilled using a kugelrhor
apparatus (120-130.degree. C., 20 mmHg) yielding 1.5 g (45%) of the
title compound as colorless oil:
.sup.1H NMR (300 MHz, CDCl.sub.3) .delta. 4.73 (4H, s), 2.15 (6H,
s).
[0237] Preparation 18. Dibenzyl methylthiomethyl phosphate
CH.sub.3SCH.sub.2OP(O)(OBu).sub.2
[0238] To a solution of bis(methylthiomethyl)ether (30 mg, 2.34
mmol) and molecular sieves (300 mg) in THF (100 ml) at room
temperature was added dibenzyl phosphate (2.74 g, 9.85 mmol)
followed by N-iodosuccinimide (608 mg, 2.71 mmol) and the solution
was stirred for 4 h. The reaction mixture was then diluted with
ethyl acetate and filtered through a pad of celite. The filtrate
was treated with a 1:1 (v:v) solution of saturated aqueous sodium
bicarbonate and 5% aqueous sodium thiosulfate. The colorless
organic extract was then washed with brine, dried over sodium
sulfate and concentrated in vacuo to provide 600 mg (69%) of the
title compound:
[0239] .sup.1H NMR (300 MHz, CDCl3) .delta. 7.35 (1OH, s), 5.29
(2H, d, J=12.2 Hz), 5.08 (4H, dd, J=8.0, 1.0 Hz), 4.68 (2H, s),
2.10 (3H, s).
EXAMPLES
[0240] The following examples are provided to illustrate the
synthesis of representative compounds of the instant invention and
are not to be construed as limiting the scope of the invention in
any manner. One skilled in the art will be able to adapt these
methods, without undue experimentation, to the synthesis of
compounds within the scope of this invention but not specifically
disclosed.
Example 1. 7-O-phosphonooxymethylpaclitaxel and its monosodium
salt
[0241] (a) preparation of 7-O-methylthiomethylpaclitaxel. 46
[0242] Benzoyl peroxide (0.98 g, 4 mmol) was added to a vigorously
stirred mixture of paclitaxel (0.85 g, 1 mmol) and dimethyl sulfide
(0.72 mL, 8 mmol) in dry acetonitrile (10 ml) at 0.degree. C.
Stirring was continued for 2.5 hours at 0.degree. C. Progress of
the reaction was monitored by silica gel TLC in toluene:acetone
(2:1, v/v) solvent system (R.sub.f tax.=0.38, R.sub.f prod.=0.64) ,
and when formation of higher mobility products was observed the
reaction was quenched by evaporation of solvents using Rotavapor at
30.degree. C. A TLC analysis of the reaction mixture indicated the
presence of some quantities of unreacted paclitaxel and
2',7-O-bis(methylthiomethyl)paclitaxel. Separation of the title
compound from the reaction mixture was achieved by flash column
chromatography on Silica Gel 60 (40 - 63 .mu.m) EM Science (100
mL), column diameter: 2 in. using ethyl acetate:hexane (1:1, v/v)
solvent system (R.sub.f prod.=0.34). The product (552 mg, 60%
yield) was recovered from fractions 12 to 18 (each fraction ca. 20
ml).
[0243] MS (FAB/matrix NOBA, NaI, KI): [M+H]+, m/z 914;
[M+Na].sup.+, m/z 936; [M+K].sup.+, m/z 952
[0244] Elemental Analysis: C: 64.28 (calc. 64.39), H: 5.85 (calc.
6.07), N: 1.46 (calc. 1.53)
[0245] UV (MeOH): .lambda.max=226 nm, E(1%/1 cm)=150, A=0.2653
[0246] IR (KBr): 3432, 3066, 2940, 1726, 1668, 1602, 1582, 1514,
1484, 1452, 1372, 1242, 1178, 1142, 1108, 1068, 1026, 990, 916,
884, 852, 802, 774, 710, 608, 570, 538, 482 cm.sup.-1.
[0247] .sup.1H-NMR (CDCl.sub.3) .delta.: 1.15 (3H, s), 1.19 (3H,
s), 1.73 (3H, s), 1.79 (H, s), 1.90 (3H, d), 2.09 (3H, s), 2.16
(3H, s), 2.29 (2H, d), 2.35 (3H, s), 2.77 (H, m), 3.70 (H, d), 3.83
(H, d), 4.17 (H, d), 4.26 (H, m, overlaps with H, d), 4.63 (2H, t),
4.77 (H, dd), 4.91 (H, d), 5.65 (H, d), 5.77 (H, dd), 6.16 (H, dd),
6.48 (H, s), 7.07 (H, d), 7.29 - 7.50 (10 H, m), 7.57 (H, m), 7.73
(2H, d), 8.08 (2H, d).
[0248] (b) preparation of 7-O-dibenzylphosphonooxymethylpaclitaxel.
47
[0249] A solution of N-iodosuccinimide (45 mg, 0.2 mM) and dibenzyl
phosphate (55 mg, 0.2 mM) in dry tetrahydrofuran (4 mL) was added
to a mixture of 7-O-methylthiomethylpaclitaxel (119 mg, 0.13 mM)
and powdered molecular sieves 4.ANG. (ca. 120 mg)in dry
1,2-dichloroethane (5 ml). The reaction mixture was stirred at room
temperature for 16 hrs. Progress of the reaction was monitored by
TLC in toluene:acetone (2:1, v/v) system (R.sub.f prod=0.48).
Molecular sieves were removed by filtration through Celite 545 and
the filtrate was extracted with methylene chloride (100 ml). The
organic layer was washed with 1% solution of sodium thiosulfate
(ca. 100 ml) and 0.5M sodium bicarbonate (100 ml) and with brine.
Extract was filtered through Whatman Phase Separator and solvents
were evaporated. Purification on Silica Gel 60 flash column in
methylene chloride:ethyl acetate (2:1, v/v) yielded
7-O-dibenzylphosphonooxymethylp- aclitaxel (41.5 mg).
[0250] (c) preparation of 7-O-phosphonooxymethylpaclitaxel and its
monosodium salt. 48
[0251] 7-O-Dibenzylphosphonooxymethylpaclitaxel (41.5 mg) was
dissolved in ethyl acetate (5 ml) and 10% palladium on charcoal (20
mg) was added. Hydrogenation was performed at 40 PSI (275 kPa) at
room temperature for 1 hour. Progress of the reaction was monitored
by TLC in chloroform:methanol:water (120:45:8, v/v). Purification
by preparative TLC (20.times.20.times.0.05 cm silica gel plate in
the analytical system) gave 7-O-phosphonooxymethylpaclitaxel (26
mg, 75% yield).
[0252] Because decomposition of
7-O-dibenzylphosphooxymethylpaclitaxel was observed during silica
gel purification, the hydrogenation procedure has been modified.
Thus, a crude extract of 7-O-dibenzylphosphonooxymethylpac- litaxel
was hydrogenated without any purification. Hydrogenation of the
crude extract of 7-O-dibenzylphosphonooxymethylpaclitaxel was
performed at 60 PSI (400 kPa) for 24 hrs.
[0253] 7-O-Phosphonooxymethylpaclitaxel (70 mg) was dissolved in 5
mL of acetone--water (1:1) solution and diluted with water to 50
ml. Dry sodium bicarbonate (18 mg, 1.2 eq.) was added. Acetone was
evaporated at room temperature using Rotavapor and the remaining
water solution was lyophilized. Crude
7-O-phosphonooxymethylpaclitaxel monosodium salt was purified by
C18 reverse phase column chromatography in water: acetonitrile
(70:30, v/v) system. Eluate was monitored by analytical HPLC (15
cm, Jones C18 column, 1 mL/min., 1=230/270 nm) in
acetonitrile:0.05M ammonium acetate buffer (45:55, v/v), pH=7,
Rt=2.09 min. Fractions containing the desired product were
combined, acetonitrile evaporated and the remaining aqueous
solution lyophilized to provide 7-O-phosphonooxymethylpaclitaxel
monosodium salt (112 mg).
[0254] MS (FAB): [M+H].sup.+, m/z 986; [M+Na].sup.+, m/z 1008
[0255] UV (MeOH): .lambda.max=230 nm, E(1%/1 cm)=248
[0256] IR (KBr): 3430, 3066, 2948, 1724, 1652, 1602,1580, 1518,
1486, 1452, 1372, 1316, 1246, 1178, 1154, 1108, 1070, 1000, 982,
946, 856, 802, 776, 710, 628, 538 cm.sup.-1.
[0257] .sup.1H-NMR (acetone-d.sub.6/D.sub.2O) .delta.: 8.05 (2H,
d), 7.92 (2H, d), 7.65 (1H, dd), 7.58 - 7.35 (9H, m, overlap), 7.23
(1H, dd), 6.38 (1H, s), 6.08 (1H, t), 5.65 (1H, d), 5.60 (1H, d),
5.10 (1H, br.s), 4.99 (1H, d), 4.97 (1H, br.s), 4.80 (1H, d), 4.28
(1H, dd), 4.11 (2H, s), 3.79 (1H, d), 2.94 (1H, m), 2.35 (3H, s),
2.35 - 2.10 (1H, m), 2.13 (3H,s), 1.95 (3H, s), 1.84 (1H, m), 1.67
(3H, s), 1.13 (6H, s, overlap).
Example 2. Alternate method for the preparation of
7-O-phosphonooxymethylp- aclitaxel.
[0258] (a) preparation of 2'-O-(benzyloxycarbonyl)paclitaxel 49
[0259] To a stirred solution of paclitaxel (150 mg, 0.176 mmol) and
N,N-diisopropylethylamine (93 .mu.L, 0.534 mmol, 3 eq.) in
anhydrous methylene chloride (4 mL) at room temperature was added
benzyl chloroformate (75 .mu.L, 0.525 mmol, 3 eq.). The reaction
mixture was stirred at room temperature for 3 h, concentrated to 2
mL, and purified on a silica gel column, using 1:1 of ethyl
acetate/hexanes as eluant, to obtain the title compound as a white
powder (150 mg, Y:86%). MP 140-150.degree. C. (decomposition).
[0260] (b) preparation of
2'-O-(benzyloxycarbonyl)-7-O-methylthiomethylpac- litaxel 50
[0261] To a cooled (dry ice--CCl.sub.4; -30.degree. C. bath temp.)
solution of 2'-O-(benzyloxycarbonyl)paclitaxel (4.935 g; 5.0 mmol)
in dry acetonitrile (80 ml) was added in succession dimethylsulfide
(3.6 ml; 40 mmol) and benzyol peroxide (4.9 g; 20.247 mmol). After
10 mins. at -30.degree. C., the cold bath was-removed and the
reaction mixture was stirred vigorously for 2 hr at room
temperature. The reaction mixture was then diluted with ethyl
acetate to a volume of 200 ml and washed with water and brine. The
organic layer was dried (MgSO.sub.4), and the solvent was then
evaporated to give a residue which was kept under vacuum for 18 h
to remove any dimethylsulfoxide that was present as a reaction side
product. The residue was purified on a silica gel column using
first ethyl acetate: hexane (1:2) as eluant to remove the less
polar impurities, followed by ethyl acetate: hexane (1:1) to give
the expected title compound as a foam. This was triturated with dry
ether and filtered to give the title compound as a fluffy solid
(5.0 g, 95%). MP 120-122.degree. C.
[0262] MS (FAB): [MH].sup.+, m/z 1048; [M+Na].sup.+, m/z 1070;
[M+K].sup.+, m/z 108
[0263] IR (KBr): 3440, 3066, 1750, 1722, 1664, 1602, 1583, 1538
cm.sup.-1.
[0264] NMR (CDCl.sub.3) .delta.: 1.177 (3H,s) 1.236 (3H, s) 1.745
(3H, s) 2.023 (3H, s) 2.121 (3H s) 2.162 (3H, s) 2.436 (3H, s)
3.887 (H, d) 4.134 (H, d) 4.197 (H, d) 4.295 (H, m) 4.964 (H, d)
5.161 (2H, d) 5.450 (H, d) 5.703 (H, d) 5.981 (H, dd) 6.257 (H, t)
6.541 (H, s) 6.920 (H, d, NH) 7.322-8.22 (15H, m).
[0265] The title compound was also prepared by the following
alternative method:
[0266] To a solution of 2'-O-(benzyloxycarbonyl)paclitaxel (2.0 g;
2.0263 mmol) in dry dimethylsulfoxide (10 ml) was added dropwise
acetic anhydride (10 ml). The resulting mixture was stirred at room
temperature for 18 h under N.sub.2, diluted with ethyl acetate (100
ml), and washed carefully with cold 6% sodium bicarbonate solution
(6.times.30 ml), cold water (6.times.30 ml) and brine. The organic
layer was dried (MgSO.sub.4), and the solvent was evaporated to
give a residue. This was purified by silica gel column and eluted
with methylene chloride, methylene chloride-5% acetonitrile, and
methylene chloride-10% acetonitrile to give the expected title
compound (1.86 g, 87.7%). This compound is identical to that
obtained via the previously described dimethyl sulfide/benzoyl
peroxide method.
[0267] (c) preparation of
2'-O-(benzyloxycarbonyl)-7-O-dibenzylphosphonoox- ymethylpaclitaxel
51
[0268] To a solution of
2-O-(benzyloxycarbonyl)-7-O-methylthiomethylpaclit- axel (5.0 g;
5.5396 mmol) in dry 1,2-dichloroethane (120 ml) was added activated
powdered 4.ANG. molecular sieves (5.0 g). To this mixture was added
dropwise at room temperature a solution mixture of
N-iodosuccinimide (1.61 g; 7.1632 mmol) and dibenzyl phosphate
(1.97 g; 7.1632 mmol) in dry tetrahydrofuran (90 ml). After
stirring vigorously at room temperature for 30 min. the reaction
mixture was filtered over Celite and the filtrate was evaporated to
dryness to give a red residue. The residue was taken up in ethyl
acetate (100 ml), washed with cold 6% NaHSO.sub.3 solution
(2.times.50 ml), cold 6% NaHCO.sub.3 solution (2.times.50 ml) and
brine (1.times.50 ml). The organic layer was dried (MgSO.sub.4) and
the solvent was evaporated to give a solid mass which was
triturated with dry ether and filtered to give the title compound
as an ivory colored solid (5.9 g, 97%). MP 124-127.degree. C.
[0269] MS (FAB): [MH].sup.+, m/z 1278; [M+Na].sup.+, m/z 1301;
[M+K].sup.+, m/z 1316
[0270] IR (KBr): 3430, 3066, 3032, 1750, 1726, 1664, 1582, 1532
cm.sup.-1
[0271] NMR (CDCl.sub.3) .delta.: 1.160 (3H, s) 1.703 (3H, s) 1.985
(3H, s) 2.164 (3H, s) 2.420 (3H, s) 3.854 (H, d) 4.151 (H, d) 4.216
(H, m) 4.298 (H, d) 4.873 (H, d) 5.043 (6H, m) 5.140 (2H, d) 5.417
(H, d) 5.670 (H, d) 5.971 (H, dd) 6.241 (H, t) 6.317 (H, s) 6.912
(H, d, NH) 7.280-8.115 (25H, m).
[0272] (d) preparation of 7-O-phosphonooxymethylpaclitaxel.
[0273] To a solution of
2'-O-(benzyloxycarbonyl)-7-O-dibenzylphosphonooxym- ethylpaclitaxel
(6.0 g; 4.7095 mmol) in ethyl acetate (120 ml) was added 10% Pd/C
(6.0 g) and the mixture was hydrogenated at 60 psi (400 kPa) for 24
hr. The reaction mixture was filtered over Celite and the solvent
was evaporated to give 4.07 g of a crude residue. This was purified
on a short silica gel column by successive elution with
chloroform:10%, 20% and 40% methanol to give the title compound as
a white solid (3.2 g, 71%) MP 155-158.degree. C.
[0274] This product has the same Rf(TLC) and same retention time
(HPLC) as an authentic sample.
[0275] MS (FAB): [MH].sup.+, m/z 964; [M+Na].sup.+, m/z 986;
[M+K].sup.+, m/z 1002; [M+K.sup.++Na.sup.+-H].sup.+, m/z 1024;
[M+2K-H].sup.+, m/z 1040
[0276] UV (MeOH): .lambda.max=230 nm, E(1%/1 cm)=252.5
[0277] IR (KBr): 3432, 3066, 2992, 1722, 1648, 1602, 1580, 1522,
1488, 1452, 1372, 1316, 1246, 1178, 1154, 1110, 1070, 1000, 980,
946, 854, 802, 776, 710, 628, 538 cm.sup.-1
[0278] .sup.1NMR (acetone-d.sub.6/D.sub.2O), .delta.: 1.08 (3H, s),
1.10 ( 3H, s), 1.63 (3H, s), 1.88 (3H, s), 1.96 (H, m), 2.13 (3H,
s), 2.32 (3H, s), 2.89 (H, m), 3.76 (H, d), 4.19 (H, m), 4.89 (H,
dd), 5.09 (H, dd), 5.55 - 5.60 (2H, overlapping d's), 6.04 (H, t),
6.32 (H, s), 720 (H, t), 7.34 - 7.67 (10 H, overlapping m's), 7.87
(2H, dd), 8.02 (2H, dd).
Example 3.
2'-O-(ethoxycarbonyl)-7-O-phosphonooxymethylpaclitaxel
[0279] (a) preparation of 2'-O-(ethoxycarbonyl)paclitaxel 52
[0280] To a solution of paclitaxel (4.35 g, 5.1 mmol) in dry
methylene chloride (51 ml) was added N,N-diisopropylethylamine
(2.67 ml, 15.3 mmol), followed by ethyl chloroformate (1.46 ml,
15.3 mmol). The reaction mixture was stirred at 0.degree. C. for 2
hrs, and then at room temperature for an additional 1 hr. The
reaction mixture was diluted with ethyl acetate (400 ml), the
organic phase was washed with saturated solution of NaHCO.sub.3
(2.times.30 ml), and with brine (30 ml). The resulting organic
phase was dried over MgSO.sub.4 to provide crude title compound
(93%) which was used in the next step without further
purification.
[0281] MS (FAB/NOBA, NaI, KI): [M+H].sup.+, m/z 926; [M+Na].sup.+,
m/z 948; [M+K].sup.+, m/z 964
[0282] HRMS (FAB/ NOBA, CsI/Gly external reference): [M+H].sup.+
m/z 926.3588 observed, C.sub.50H.sub.56NO.sub.16, calculated value:
926.3599 (deviation .DELTA.=1.2 ppm)
[0283] .sup.1HNMR (CDCl.sub.3): .delta. 1.13 (3H, s), 1.23 (3H, s),
1.30 (3H, t), 1.67 (3H, s), 1.92 (3H, s), 2.21 (3H, s), 2.37 (H,
d), 2.45 (3H, s), 2.54 (H, m), 3.80 (H, d), 4.15 - 4.32 (4H, m's
overlapping), 4.43 (H, dd), 4.96 (H, d), 5.42 (H, d), 5.68 (H, d),
5.98 (H, dd), 6.28 (2H, m's, overlapping), 7.00 (H, d), 7.34 - 7.59
(11H, m's overlapping), 7.74 (2H, d), 8.12 (2H, d).
[0284] Alternate Run:
[0285] Paclitaxel (5.40 g, 6.324 mmol) in dry dichloromethane (63
mL) was cooled to 0.degree. C. and treated with neat N,N-
diisopropylethylamine (3.30 mL, 3 equiv) and then neat ethyl
chloroformate (1.81 mL, 3 equiv) dropwise over a 5 min period. The
reaction was monitored by TLC (50% ethyl acetate in hexane). After
2 h at 0.degree. C. and 16 h at room temperature, the reaction was
complete and the yellow-orange solution was diluted with ethyl
acetate (300 mL) and washed with saturated sodium bicarbonate
(3.times.75 mL) and brine (75 mL)). Drying (MgSO.sub.4) and
evaporation afforded crude title compound, which was purified by
precipitation: dichloromethane (ca. 100 mL) was added followed by
cooling and addition of hexane (ca 60 mL) to the cloud point. After
cooling in ice for several hours, the solid was collected by
filtration. Yield 5.17 g (88%).
[0286] Alternate Run:
[0287] In a flame dried, single necked 3 L flask was dissolved
paclitaxel (99.0 g, 115.9 mmol) in 1,350 mL of dry methylene
chloride under the argon atmosphere. The solution was cooled to
-10.degree.. N,N-diisopropylethylamine (52.4 g, 405.7 mmol) was
added slowly (addn. time .about.3 min.), followed by ClCO.sub.2Et
(31.45 g, 289.8 mmol; addn. time .about.15 min.). The resulting
mixture was stirred overnight (16 hrs.) at -4.degree. C. The
reaction was judged incomplete by TLC. Another charge of
N,N-diisopropylethylamine (2.62 g, 20.28 mmol) was added, followed
by ClCO.sub.2Et (2.20 g, 20.28 mmol) and the stirring was continued
for 3 hrs at -4.degree. C. No starting material was detected by
TLC. The cold mixture was diluted with ethyl acetate (1.5 L) and
transferred to a separatory funnel. It was then washed with 5%
KHSO.sub.4 (2.times.500 mL), water (1.times.500 mL), 5% KHSO.sub.4
(1.times.500 mL), water (1.times.500 mL), satd. NaHCO.sub.3
(2.times.500 mL) and brine (2.times.500 mL), dried (MgSO.sub.4) and
the solvents were removed in vacuo to give 147 g of the crude
product. The residue was dissolved in hot methylene chloride (800
mL, bath temp. 42.degree. C.) and hexanes were added dropwise (530
mL) with stirring, while the temperature was maintained. The
crystallizing mixture was set aside for 3 hrs. at room temperature
and then in the cold room (0.degree. C.) overnight. The heavy white
crystals were collected by filtration and washed with
hexanes/CH.sub.2Cl.sub.2 1:1 (v/v) (2.times.200 mL). After drying
on the suction filter for 1 hr. it was dried in vacuo (.about.1.0
mmHg) overnight to give 95.7 g (89% yield) of the title compound
(homogeneity index as measured by HPLC=98.5%).
[0288] (b) preparation of
2'-O-(ethoxycarbonyl)-7-O-methylthiomethylpaclit- axel 53
[0289] To a solution of 2'-O-(ethoxycarbonyl)paclitaxel (4.38 g,
4.7 mmol) in dry dimethylsulfoxide (12.5 ml) was added acetic
anhydride.(12.5 ml). The reaction mixture was stirred for 24 hrs at
room temperature and then diluted with ethyl acetate (500 ml),
washed with saturated solution of NaHCO.sub.3 (3.times.40 ml) and
with water (2.times.40 ml). The resulting organic layer was dried
over MgSO.sub.4, and the solvents were evaporated in vacuo to
dryness. The residue was purified by silica gel chromatography (40%
ethyl acetate in hexanes) to afford the desired title compound
(4.39 g, 94%).
[0290] MS (FAB/NOBA, NaI, KI): [M+H].sup.+, m/z 986; [M+Na].sup.+,
m/z 1008; [M+K].sup.+, m/z 1024
[0291] HRMS (FAB/NOBA, CsI/Gly external reference): [M+H].sup.+ m/z
986.3646 (calculated value: 986.3633, deviation .DELTA.=1.3
ppm)
[0292] .sup.1HNMR (CDCl3) .delta.: 1.18 (3H, s), 1.20 (3H, s), 1.30
(3H, s), 1.75 (3H, s), 1.84 (H, m), 2.09 (3H, s), 2.11 (3H, s),
2.16 (3H, s), 2.24 (H, d), 2.37 (H, d), 2.45 (3H, s), 2.80 (H, m),
3.68 (H, d), 4.08 - 4.33 (5H, m, overlapping), 4.65 (2H, s), 4.96
(H, d), 5.43 (H, d), 5.69 (H, d), 5.98 (H, dd), 6.26 (H, t), 6.55
(H, s), 7.00 (H, d), 7.32 - 7.61 (11H, m, overlapping), 7.73 (2H,
dd), 8.11 (2H, dd).
[0293] Alternate Run:
[0294] 2'-O-(Ethoxycarbonyl)paclitaxel (2.260 g, 2.4406 mmol) was
dissolved in anhydrous dimethylsulfoxide (6 mL), and acetic
anhydride (6 mL) was added in one lot at room temperature. The
reaction was monitored by HPLC (C18 analytical column; 60%
acetonitrile - 40% 10 mM ammonium phosphate buffer, pH 6). After 30
h, the solution was diluted with ethyl acetate (250 mL) and washed
with saturated aqueous bicarbonate (3 times) then water and brine.
After drying over magnesium sulfate and filtration, the crude
product was chromatographed on silica (40% ethyl acetate in hexane)
to yield the title compound as a white foam (2.030 g, 91%) that was
90% pure by HPLC. A portion was further purified by a second column
(5% acetonitrile in dichloromethane) to afford material that was
ca. 97% pure by HPLC.
[0295] Alternate method for the preparation of
2'-O-(ethoxycarbonyl)-7-O-m- ethylthiomethylpaclitaxel.
[0296] 2'-O-(Ethoxycarbonyl)paclitaxel (4.170 g, 4.503 mmol) was
dissolved in anhydrous acetonitrile (68 mL) at -40.degree. C., and
dimethyl sulfide (3.2 mL, 44.10 mmol) was added, followed by
benzoyl peroxide (4.400 g, 18.24 mmol). The mixture was placed in
an ice bath and stirred at 0.degree. C., and the course of the
reaction was monitored by TLC (40% ethyl acetate in hexane). After
3 h. no starting material was detected, and the solution was worked
up by adding ethyl acetate (250 mL) and saturated aqueous sodium
bicarbonate (100 mL). The organic phase was further washed with
bicarbonate, water, and brine, then dried over magnesium sulfate
and filtered. The residue was purified by silica gel flash
chromatography (4% acetonitrile in dichloromethane), to yield the
title compound as a white foam (2.571 g, 58% yield). The purity of
this sample was judged as >97% by HPLC. The NMR spectrum was
identical to the one reported above.
[0297] Alternate run for preparing
2'-O-(ethoxycarbonyl)-7-O-methylthiomet- hylpaclitaxel.
[0298] 2'-O-(Ethoxycarbonyl)paclitaxel (49.3 g, 53.2 mmol) was
placed in a flame dried single necked 1 L flask and dissolved in
dry acetonitrile (500 mL) at room temperature. Methyl sulfide (39.1
mL, 0.532 mol) was rapidly added via syringe. The stirred reaction
mixture was cooled to -16.degree. C. in an ice/salt bath and solid
benzoyl peroxide (51.6 g, 0.213 mol) was added to the mixture in
one lot. (Full four equivalents are required for the reaction to
proceed to completion.) Stirring was continued for 30 minutes,
during which time the temperature rose to .about.-10.degree. C. The
reaction medium remained heterogeneous throughout this period
(benzoyl peroxide has not dissolved completely). The cooling bath
was changed to ice/water, the temperature was raised to 0.degree.
C. and the remaining benzoyl peroxide dissolved .about.5 min. after
the warm-up. The reaction was judged complete by TLC after stirring
at 0.degree. C. for another 2.5 hours. The volume of the solution
was reduced .about.200 mL by removing the solvent on a rotovap and
it was then transferred to a separatory funnel where it was washed
with heptane (5.times.500 mL). The acetonitrile layer was diluted
with ethyl acetate (1.5 L) and washed with a 3:1 mixture satd.
NaHCO.sub.3/5% K.sub.2CO.sub.3 (v/v) (2.times.500 mL), satd.
NaHCO.sub.3 (2.times.500 mL), half-satd. brine (1.times.500 mL) and
brine (1.times.500 mL), dried (MgSO.sub.4) and the solvents were
removed in vacuo to give 67.0 g of the crude product. It was
dissolved in acetone (200 mL), warmed to 40.degree. C. in a water
bath and hexanes were added dropwise with stirring until the
cloudiness was observed (400 mL). The crystallizing mixture was set
aside for 3 hrs. at room temperature and then transferred to a cold
room (0.degree. C.) where it was kept overnight (16 hrs.). A thick
cake was formed. The solid was collected by filtration and washed
with hexanes/acetone 3:1 (v/v) (2.times.50 mL). The resulting white
crystals were dried on the suction filter for 1 hr. and then in
vacuo (.about.0.5 mmHg) overnight to give 47.5 g (91% yield) of the
title compound (homogeneity index as measured by HPLC=94.8%).
[0299] (c) preparation of
2'-O-(ethoxycarbonyl)-7-O-dibenzylphosphonooxyme- thylpaclitaxel.
54
[0300] A solution of N-iodosuccinimide (1.953 g, 8.65 mmol) and
dibenzyl phosphate (2.41 g, 8.65 mmol) in tetrahydrofuran was added
to a mixture of
2'-O-(ethoxycarbonyl)-7-O-methylthiomethylpaclitaxel (5.677 g, 5.76
mmol) and 4.ANG. molecular sieves (5.7 g) in methylene chloride
(100 ml) at room temperature. The reaction mixture was stirred for
40 min. at room temperature. After this period the reaction was
complete as judged by TLC. The reaction mixture was filtered
through Celite and the filtrate was concenterated in vacuo to give
a brownish residue which was diluted with ethyl acetate (800 ml),
the organic phase was washed with 1% Na.sub.2SO.sub.3 (2.times.80
ml), then washed with 5% brine (2.times.50 ml). The organic phase
was concentrated in vacuo and dried. Chromatography of the
resulting residue (50 - 60% ethyl acetate in hexanes) gave the
desired title compound (6.23 g, 89%).
[0301] MS (FAB/NOBA, NaI, KI): [M+Na].sup.+, m/z 1238; [M+K].sup.+,
m/z 1254
[0302] HRMS (FAB/NOBA, CsI/Gly external reference): [M+Na].sup.+
m/z 1216.4291(C.sub.65H.sub.71NO.sub.20P calculated value:
1216.4307; deviation .DELTA.=1.3 ppm)
[0303] .sup.1HNMR (CDCl.sub.3), .delta.: 1.18 (3H, s), 1.21 (3H,
s), 1.30 (3H, t), 1.67 (6H, s), 1.80 (H, s), 1.93 (H, m), 1.99 (3H,
d), 2.18 (3H, s), 2.23 (H, m), 2.38 (H, m), 2.45 (3H, s), 2.80 (H,
m), 3.86 (H, d), 4.14 - 4.32 (5H, m's, overlapping), 4.88 (H, d),
5.00 - 5.07 (4H, m's, overlapping), 5.42 (H, d), 5.68 (H, d), 5.96
(H, dd), 6.26 (H, t), 6.33 (H, s), 6.95 (H, d), 7.30 - 7.61 (11H,
m's overlapping), 7.75 (2H, dd), 8.12 (2H, dd).
[0304] Alternate Run:
[0305] To a solution of
2'-O-(ethoxycarbonyl)-7-O-methylthiomethylpaclitax- el (350 mg,
0.355 mmol) in anhydrous tetrahydrofuran (8 mL) was added a
solution of N-iodosuccinimide (120 mg, 0.532 mmol) and dibenzyl
phosphate (148 mg, 0.532 mmol)in tetrahydrofuran (5 mL). The
reaction was monitored by HPLC (C18 column; 70% acetonitrile, 30%
10 mM ammonium phosphate, pH 6). After 2 h, less than 5% starting
material was detected, and the reaction was worked-up. The solution
was diluted with ethyl acetate (75 mL), and washed with 1% aqueous
sodium bisulfite (2.times.50 mL) and brine (50 mL). After quick
drying over magnesium sulfate and filtration, the solvent was
evaporated. Silica gel flash chromatography (45% ethyl
acetate/hexane) provided the title compound as a white foam (281
mg, 65%). HPLC analysis indicated a purity of ca. 95%.
[0306] Alternte Run:
[0307] Crushed 4 A molecular sieves were placed in a flame dried
one-necked 1 L flask which was then connected to a vacuum line
(.about.0.5 mmHg). The sieves were heated with a heatgun for
.about.10 min. while being shaken manually. After cooling under
vacuum argon was introduced into the flask and
2'-O-(ethoxycarbonyl)-7-O-methylthiomethylp- aclitaxel (37.5 g,
38.03 mmol) was added, followed by dibenzyl phosphate (14.8 g,
53.24 mmol) and THF (400 mL). The heterogeneous mixture was
vigorously stirred for 15 min. at room temperature with a magnetic
stirrer. In a separate flame dried flask, N-iodosuccinimide (10.7
g, 47.54 mmol) was dissolved in THF (50 mL) under argon. (During
the preparation of the NIS solution, liquid transfer and during the
reaction course, the vessels were covered with aluminum foil for
protection against light.) It was then added slowly (10 min) to the
reaction mixture via a syringe. The flask containing NIS was washed
with 5 mL of THF and transferred to the reaction mixture, which was
then stirred for 2 hrs. at room temperature. TLC analysis showed
absence of the starting material. The deeply red colored solution
was filtered through a pad of Celite.RTM. directly into a
vigorously stirred bi-phasic mixture containing ethyl acetate (500
mL), 10% aq. sodium thiosulfate (300 mL) and satd. sodium
bicarbonate (200 mL). The red color disappeared in a few seconds
giving a colorless solution. The Celite.RTM. pad was washed with
EtOAc (.about.100 mL) and both liquid layers were transferred into
a separatory funnel. The organic layer was diluted with 1 L of
EtOAc, the layers were separated and the organic layer was washed
with a mixture of satd. NaHCO.sub.3 and 5% K.sub.2CO.sub.3 (3:1
v/v, 2.times.500 mL), then satd. NaHCO.sub.3 (2.times.500 mL),
half-saturated brine (1.times.500 mL) and brine (1.times.500 mL).
The extract was dried with anhydrous MgSO.sub.4 and filtered. It
was treated with 5.0 g of neutral Norit (charcoal) by stirring at
room temperature for 15 min. It was filtered again through a
Celite.RTM. pad and the solvent was removed under the reduced
pressure to give 52 g of the crude product. It was dissolved in
toluene/methylene chloride (280 mL/25 mL) and hexanes were added
dropwise (20 mL). After being set aside for 3 hrs. at room
temperature the crystallizing mixture was left at 0.degree. C.
overnight. A pale yellow solid was formed on the flask walls. After
decanting the mother liquor, the residue was triturated with
toluene (50 mL), filtered, washed with toluene and dried on the
suction filter for 30 min. It was then transferred to a desiccator
with Drierite.RTM. and further dried in vacuo (.about.0.5 mmHg) for
four hours to give 24.4 g (53% yield) of the title compound
(homogeneity index as measured by HPLC=95.9%). The mother liquor
was evaporated to dryness, triturated with toluene (100 mL),
filtered, washed with toluene and dried on the suction filter for
30 min. After drying in a desiccator as described above it gave
12.5 g (27% yield) of the same product (homogeneity index as
measured by HPLC=97.1%).
[0308] (d) preparation of
2'-O-(ethoxycarbonyl)-7-O-phosphonooxymethylpacl- itaxel; its
monosodium, monopotassium, triethylamine, arginine, lysine,
ethanolamine, N-methylglucamine, and triethanolamine salts. 55
[0309] To a solution of
2'-O-(ethoxycarbonyl)-7-O-dibenzylphosphonooxymeth-
ylpaclitaxel(1.23 g, 1.01 mmol) in dry ethyl acetate (40 ml) was
added 10% Pd on carbon (428 mg, 10%, 0.404 mmol). The reaction
mixture was subjected to hydrogenation (60 PSI=400 kPa) with
continuous shaking for 24 hrs. The solid was filtered off through
Celite, then the Celite was rinsed several times with ethyl
acetate. The filtrate was concentrated to give free acid form of
the title compound (1.01 g, 80% purity as judged by HPLC). The
impurities were removed at the next step by preparative C-18 column
chromatography.
[0310] MS (FAB/NOBA, NaI, KI): [M+Na].sup.+, m/z 1058; [M+K].sup.+,
m/z 1074; [M+2Na-H].sup.+, m/z 1080; [M+Na+K-H].sup.+, m/z 1096;
[M+2K-H].sup.+, m/z 1112
[0311] HR-MS (FAB/NOBA, CsI/Gly, external reference): [M+Na].sup.+,
m/z 1058.3163 (C.sub.51H.sub.50NO.sub.20PNa calculated value:
1058.3188; deviation .DELTA.=2.3 ppm)
[0312] .sup.1H NMR (acetone-d.sub.6/D20) .delta.: 1.13 (3H, s),
1.21 (3H, s), 1.66 (3H, s), 1.87 (H, m), 1.93 (3H, s), 2.14 (3H,
s), 2.18 (H, m), 2.44 (3H, s), 2.95 (H, m), 3.81 (H, d), 4.12 (2H,
s), 4.15 - 4.27 (3H, m's overlapping), 4.92 - 4.99 (2H, br.m's
overlapping), 5.15 (H, br.s), 5.48 (H, d), 5.61 (H, d), 5.84 (H,
dd), 6.07 (H, t), 6.36 (H, s), 7.25 (H, t), 7.28 - 7.69 (10 H, m's
overlapping), 7.89 (2H, dd), 8.08 (2H, dd), 8.86 (H, d).
[0313] Alternate Run:
[0314]
2'-O-(Ethoxycarbonyl)-7-O-(dibenzylphosphonooxymethyl)paclitaxel
(490 mg, 0.402 mmol) in ethyl acetate (20 mL) was hydrogenated in a
Parr shaker at 60 psi (400 kPa) in the presence of palladium on
characoal (10% w/w, 150 mg). Monitoring was carried out by TLC and
HPLC. When no more starting material nor an intermediate
(presumably the monobenzyl phosphate) were detected (26 h), the
suspension was filtered through Celite and evaporated to dryness.
HPLC analysis showed a purity of 88-92%.
[0315] Alternate Run:
[0316] 2'-O-(Ethoxycarbonyl)-7-O-phosphonooxymethylpaclitaxel
triethylamine salt to be described below (5.4 g, 4.75 mmole) was
partitioned vigorously between EtOAc (100 mL) and 5% NaHSO.sub.4
(45 ml) with stirring at 0.degree. C. for 30 minutes. The aqueous
layer was separated and extracted with EtOAc (20 ml). The combined
EtOAc layer was washed with half-brine (25 ml), brine (25
mL.times.2), dried over NaSO.sub.4 and filtered to give a solution
of the acid (.about.4.75 mmole) in EtOAc (.about.150 mL). This
EtOAc solution was then concentrated to dryness on a rotary
evaporator to give 3.75 g of the title compound in free acid form
in 95% yield. HPLC analysis showed homogeneity index of 96.1%.
[0317] The monosodium salt was prepared as follows:
[0318] A sample of
2'-O-(ethoxycarbonyl)-7-O-phosphonooxymethylpaclitaxel (1.6 g, 1.55
mmol) was dissolved in acetonitrile (30 ml) by sonication. This
solution was diluted with water (30 ml) and 1.1M solution of
NaHCO.sub.3 (2.11 ml, 2.32 mmol) was added, alternately shaking and
sonicating to obtain a solution (5-20 min). The somewhat milky
solution was applied onto a C-18 column, washing with two column
volumes of water, then eluting the monosodium salt with 25%
acetonitrile/water. The appropriate fractions were pooled, the
acetonitrile evaporated, and the aqueous phase lyophilized, to
yield the monosodium salt of the title compound (850 mg, ca 50%),
having HPLC purity of 97%.
[0319] MS (FAB/NOBA, NaI, KI): [M+Na].sup.+, m/z 1180
[0320] HR - MS (FAB/NOBA, CsI/Gly external reference):
[M+Na].sup.+, m/z 1080.2968 (C.sub.51H.sub.57NO.sub.20PNa.sub.2
calculated value: 1080.3007; deviation D=3.6 ppm)
[0321] Elemental analysis: C: 52.65 (calc. 56.72), H: 5.06 (calc.
5.23), N: 1.20 (calc. 1.30), Na: 2.74 (calc. 2.12)
[0322] IR (KBr): 3430, 3066, 2988, 1746, 1722, 1660, 1602, 1582,
1526, 1488, 1452, 1374, 1246, 1178, 1150, 1108, 1070, 1052, 1026,
1002, 966, 912, 834, 792, 776, 710, 628, 538 cm.sup.-1.
[0323] .sup.1H-NMR (DMSO-d.sub.6, D.sub.2O, acetone-d.sub.6)
.delta.: 1.10 (6H, s) , 1.23 (3H, t), 1.64 (3H, s), 1.70 (H, m),
1.90 (3H,s), 1.99 (H, m), 2.14 (3H, s), 2.37 (3H, s), 2.98 (H, m),
3.74 (H, d), 4.07 (2H, s), 4.13 - 4.26 (3H, m, overlapping), 4.80
(H, br.dd), 4.97 (H, d), 5.09 (H, br.t), 5.44 (H, d), 5.55 (H, d),
5.99 (H, t), 6.34 (H, s), 7.22 (H,t), 7.43 - 7.69 (10 H, m,
overlapping), 7.92 (2H, dd), 8.06 (2H, dd).
[0324] The sodium salt can also be prepared as follows:
[0325] Crude 2'-O-(ethoxycarbonyl)-7-O-phosphonooxymethylpaclitaxel
(89%; 70 mg, 0.060 mmol), in EtOAc (2 ml) was treated with a
solution of sodium ethylhexanoate (87.5 mM in EtOAc, 1.0 ml, 0.0875
mmol) at room temperature with stirring. After stirring at room
temperature for 1 h, hexane (1.2 ml) was added to the cloud point.
After storing at -20.degree. C. for 2 h, the fine amorphous powder
was filtered (with some difficulty, very slow) through fine filter
paper, to yield 45 mg (70%) of the sodium salt. This was 95.2% pure
by HPLC and contained a small amount of ethylhexanoic acid
(NMR).
[0326] The triethanolamine salt was prepared as follows:
[0327] 2'-O-(Ethoxycarbonyl)-7-O-phosphonooxymethyl-paclitaxel,
crude from the hydrogenation (89% by HPLC) (0.69 g, 0.593 mmol
after correction for impurities) was dissolved in ethyl acetate (10
ml), and stirred slowly while a solution of triethanolamine (0.11M
in EtOAc, used 5.1 ml, 0.95 eq) was added dropwise. The milky
solution obtained by this procedure was digested at 0.degree. C.
for 2 h, then filtered on file filter paper, rinsing with cold
EtOAc. Yield: 499 mg (80%) of an amorphous, fine, non-electrostatic
powder that was dried overnight in vacuo. HPLC shows 96.6% purity
(C-18, 45% 5mM Q.sub.12+10 mM ammonium phosphate pH 6, 55%
actonitrile). NMR spectrum (D.sub.2O/acetone/DMSO) shows traces of
ethyl acetate and no other clearcut impurities. It analyzes for a
2-3 x hydrate.
[0328] The triethanolamine salt of lesser priority obtained from
another experiment was further purified by the following procedure.
The triethanolamine salt (approx. 2 g ) was dissolved in about 30%
acetonitrile/water. This solution was eluted with slight nitrogen
pressure through a column of C18 (Bakerbond) with a gradient of 20%
to 40% acetonitrile in water. The fractions containing the desired
triethanolamine salt were collected; the acetonitrile was removed
by rotary evaporation under reduced pressure. The aqueous solutions
were frozen and lyophilized overnight to afford 1.4 grams of the
triethanolamine salt with a purity of 97.5%.
[0329] The triethanolamine salt can also be prepared as
follows:
[0330] 2-O-(Ethoxycarbonyl)-7-O-phosphonooxymethyl-paclitaxel
triethylamine salt (3.0 g, 2.64 mmole) was partitioned between
EtOAc (60 ml) and 5% NaHSO.sub.4 (30 ml) with vigorous stirring at
0.degree. C. for 15 minutes. The aqueous layer was separated and
extracted with EtOAc (10 mL). The combined EtOAc layer was washed
with brine (15 ml), dried over Na.sub.2SO.sub.4, filtered to give a
solution of the acid (.about.2.64 mmole) in EtOAc (.about.70 ml).
To this EtOAc solution at room temperature was added dropwise with
vigorous stirring N(CH.sub.2CH.sub.2OH).sub.3 (0.35 ml, 2.64 mmole)
over a period of 5 minutes. The resulting suspension was stirred
for an additional 1 hr and then it was filtered, washed with EtOAc
(15 ml.times.2), dried in vacuo to give 2.8 g of the
triethanolamine salt in 89% yield. HPLC analysis showed homogeneity
index of 98.7%; mp.: >157.degree. C. with decomposition.
[0331] Elemental analysis calculated for
C.sub.56H.sub.73N.sub.2O.sub.23P.- cndot.2.0 H.sub.2O.cndot.0.3
EtOAc: C, 55.60; H, 6.48; N, 2.27; KF (H.sub.2O), 2.92. Found:
55.94; H, 6.59; N, 2.43; KF (H.sub.2O), 3.50.
[0332] The triethylamine salt was prepared as follows:
[0333] To the solution of
2'-O-(ethoxycarbonyl)-7-O-dibenzylphosphonooxyme- thylpaclitaxel
(10 g, 8.23 mmole), in EtOAc (350 ml), at room temperature was
added 10% Pd on carbon (2 g, 20% load). The resulting suspension
was degassed by evacuating air and then purging with argon. This
process was repeated two additional times. The argon then was
replaced with hydrogen following the same degassing procedure. The
resulting suspension was stirred under a balloon hydrogen pressure
(2-3 pound per square inch) for 16 hr at room temperature with
vigorous stirring. The hydrogen was evacuated and replaced with
argon three times following the degassing procedure. The resulting
suspension was filtered through a pad of Celite. To this
homogeneous filtrate was slowly added Et.sub.3N (8.23 mmole, 1.14
mL) over a period of 5 min with vigorous stirring. The resulting
fine white suspension was stirred for an additional 30 min. It was
filtered through a fritted funnel. The filter cake was dried in
vacuo (1 mmHg) for 16 hr to give 8.22 g of the title triethylamine
salt in 88% yield. HPLC analysis showed homogeneity index of 97.4%;
mp.: >178.degree. C. with decomposition.
[0334] Elemental analysis calculated for
C.sub.57H.sub.73N.sub.2O.sub.20P.- cndot.4.5 H.sub.2O: C, 56.19; H,
6.79; N, 2.30; KF (H.sub.2O), 6.65. Found: 56.33; H, 6.87; N, 2.32;
KF (H.sub.2O), 7.96.
[0335] Alternate run for making the triethylamine salt:
[0336]
2-O-(Ethoxycarbonyl)-7-O-dibenzylphosphonooxymethylpaclitaxel (5.67
g, 4.66 mmol) was added to a 250 mL flask and dissolved in ethyl
acetate (150 mL). The flask was equipped with a three-way valve
with one connection to house vacuum and one connection to an argon
line. Using the valve, the flask was partially evacuated and then
purged with argon. This process was repeated two additional times.
Palladium on activated carbon (10% Pd) (0.85 g) was added to the
flask. The argon line attached to the three-way valve was replaced
with a hydrogen-filled balloon. Using the valve, the flask was
partially evacuated and then purged with hydrogen. This process was
repeated four additional times. The resulting mixture was stirred
at room temperature under the hydrogen balloon atmosphere
overnight. TLC analysis 17 hours after the initial exposure to
hydrogen showed the starting material to be absent. The hydrogen
balloon attached to the three-way valve was replaced with an argon
line. Using the valve, the flask was partially evacuated and then
purged with argon. This process was repeated two additional times.
The contents of the flask were vacuum-filtered through a pad of
Celite. The Celite was rinsed with ethyl acetate (2.times.10 mL).
To the stirring filtrate was added NEt.sub.3 (0.650 mL, 4.66 mmol).
The resulting suspension was stirred at room temperature for two
hours, and the volume was then reduced to .about.150 mL via a
rotovap. The solid was filtered, washed with ethyl acetate
(2.times.10 mL) and dried under vacuum to give 4.76 g (90% yield)
of the title triethylamine salt as a white powder (homogeneity
index of the product was determined to be 96.6% by HPLC
analysis).
[0337] Alternate run for making the triethylamine salt:
[0338]
2'-O-(Ethoxycarbonyl)-7-O-dibenzylphosphonooxymethylpaclitaxel
(5.17 g, 4.25 mmol) was added to a 250 mL flask and dissolved in
ethyl acetate (150 mL). The flask was equipped with a three-way
valve with one connection to house vacuum and one connection to an
argon line. Using the valve, the flask was partially evacuated and
then purged with argon. This process was repeated two additional
times. Palladium on activated carbon (10% Pd) (0.86 g) was added to
the flask. The argon line attached to the three-way valve was
replaced with a hydrogen-filled balloon. Using the valve, the flask
was partially evacuated and then purged with hydrogen. This process
was repeated five additional times. The resulting mixture was
stirred at room temperature under the hydrogen balloon atmosphere
overnight. TLC analysis 16 hours after the initial exposure to
hydrogen showed the starting material to be absent. The hydrogen
balloon attached to the three-way valve was replaced with an argon
line. Using the valve, the flask was partially evacuated and then
purged with argon. This process was repeated two additional times.
The contents of the flask were vacuum-filtered through a pad of
Celite. The Celite was rinsed with ethyl acetate (4.times.10 mL).
To the stirring filtrate was added NEt.sub.3 (0.590 mL, 4.25 mmol).
The resulting suspension was stirred at room temperature for one
hour, and the volume was then reduced to .about.140 mL via a
rotovap. The solid was filtered, washed with ethyl acetate (10 mL)
and dried under vacuum to give 4.46 g (92% yield) of the title
triethylamine salt as a white powder (homogeneity index as
determined by HPLC analysis was 96.7%).
[0339] The lysine salt was prepared as follows:
[0340]
2'-O-(ethoxycarbonyl)-7-O-dibenzylphosphonooxymethylpaclitaxel
(15.0 g, 12.34 mmole) was added portionwise to a suspension of 10%
palladium on carbon (20% load, 3 g) in EtOH (600 ml, 200 proof) at
0.degree. C. The resulting suspension was degassed by evacuating
air and purging with argon. This process was repeated two
additional times. The argon then was replaced with hydrogen
following the same degassing procedure with vigorous stirring. The
resulting mixture was stirred at 0.degree. C. for 2 hrs. The
cooling bath was removed and the reaction solution was stirred at
ambient temperature for additional 4-1/2hrs. The reaction mixture
was degassed by evacuating hydrogen and purging with argon three
times. It was filtered under argon through a pad of Celite. To the
resulting filtrate was slowly added a solution of lysine (1.63 g,
0.94 eq) in a 1:1 mixture of H.sub.2O:EtOH (200 proof) (20 ml) over
a period of 5 minutes with vigorous stirring. To the resulting
white suspension was added distilled water (110 ml) and stirred for
30 minutes. It was warmed to about 55.degree. C. The resulting
homogeneous solution was kept in an oil bath set at 50.degree. C.
and slowly cooled down to room temperature for 16 hrs and 4.degree.
C. for 3 hrs. It was filtered and suction dried for 16 hrs to give
11.8 g (.about.80% yield) of the lysine salt with homogeneity index
of 99.0% as determined by HPLC; mp.: >170.degree. C. with
decomposition.
[0341] Elemental analysis calculated for
C.sub.57H.sub.72N.sub.3O.sub.22P.- cndot.8.0 H.sub.2O: C, 51.62; H,
6.69; N, 3.17; KF (H.sub.2O), 10.87. Found: 51.76; H, 6.57; N,
3.48; KF (H.sub.2O), 11.42.
[0342] The ethanolamine salt was prepared as follows:
[0343] 2'-O-(Ethoxycarbonyl)-7-O-phosphonooxymethylpaclitaxel
triethylamine salt (3.0 g, 2.64 mmole) was partitioned between
EtOAc (60 ml) and 5% NaHSO.sub.4 (30 ml) with vigorous stirring at
0.degree. C. for 15 minutes. The aqueous layer was separated and
extracted with EtOAc (15 ml). The combined EtOAc layer was washed
with brine (15 ml), dried over Na.sub.2SO.sub.4, filtered to give a
solution of the free acid (.about.2.64 mmole) in EtOAc (.about.70
ml). To this EtOAc solution at room temperature was added dropwise
with vigorous stirring a solution of H.sub.2NCH.sub.2CH.sub.2OH
(0.15 ml, 2.64 mmole) in EtOAc (5 mL) over a period of 5 minutes.
The resulting suspension was stirred for an additional 1 hr and
then it was filtered, washed with EtOAc (15 ml.times.2), and dried
in vacuo to give 2.6 g of the title ethanolamine salt in 89% yield.
HPLC analysis showed homogeneity index of 97.8%; mp.:
>130.degree. C. with decomposition.
[0344] Elemental analysis calculated for
C.sub.53H.sub.65N.sub.2O.sub.21P.- cndot.2.5 H.sub.2O: C, 55.73; H,
6.18; N, 2.45; KF (H.sub.2O), 3.94. Found: C, 55.76; H, 6.39; N,
2.45; KF (H.sub.2O), 6.00.
[0345] The arginine salt was prepared as follows:
[0346]
2'-O-(Ethoxycarbonyl)-7-O-dibenzylphosphonooxymethylpaclitaxel
(30.0 g, 24.69 mmole) was added portionwise to a suspension of 10%
palladium on carbon (20%, load, 6 g) in EtOH (900 ml, 200 proof) at
0.degree. C. The resulting suspension was degassed by evacuating
air and purging with argon. This process was repeated two
additional times. The argon then was replaced with hydrogen
following the above degassing procedure with vigorous stirring. The
resulting mixture was stirred at 0.degree. C. for 2 hrs. The
cooling bath was removed and the reaction solution was stirred at
ambient temperature for additional 24 hrs. The reaction mixture was
degassed by evacuating hydrogen and purging with argon three times
following the above degassing procedure. It was filtered under
argon through a pad of Celite. The filtrate was divided into two
equal portions and EtOH (190 ml, 200 proof) was added to each
portion. To one portion (.about.630 ml) was slowly added a solution
of arginine (2.0 g, 0.94 eq) in a 2:1 mixture of H.sub.2O: EtOH
(200 proof) (20 ml) over a period of 5 minutes with vigorous
stirring. To the resulting white suspension was added distilled
water (100 ml) and stirred for 30 minutes and then warmed to about
60.degree. C. It was filtered hot and the filtrate was kept in an
oil bath set at 50.degree. C., allowed to cool down to room
temperature and kept at room temperature for 2 hrs and at 4.degree.
C. for 2 hrs. It was filtered and washed with cold 3% H.sub.2O in
EtOH (100 ml) and suction dried for 16 hrs to give 12.95 g
(.about.86% yield) of the title arginine salt with homogeneity
index of 96.7%.
[0347] This material (12.95 g) was dissolved in a mixture of 15%
H.sub.2O in EtOH (.about.700 ml) at 55.degree. C. The solution was
cooled down and kept at 30.degree. C. for 3-1/2 hrs, room
temperature for 16 hrs, and 4.degree. C. for 3 hrs. The resulting
crystals were filtered, washed with cold 2% H.sub.2O in EtOH (50
ml.times.2), suction dried for 4 hrs, and then dried in vacuo (1
mmHg) for 16 hrs to give 10.2 gs (.about.80% yield) of the title
arginine salt (homogeneity index was 98.5%);mp.: >176.degree. C.
with decomposition.
[0348] Elemental analysis calculated for
C.sub.57H.sub.72N.sub.5O.sub.22P.- cndot.6.4 H.sub.2O: C, 51.65; H,
6.45; N, 5.28; KF (H.sub.2O), 8.7. Found: C, 51.86; H, 6.65;
N,5.53; KF (H.sub.2O), 8.72.
[0349] The N-methylglucamine salt was prepared as follows:
[0350]
2'-O-(Ethoxycarbonyl)-7-O-dibenzylphosphonooxymethylpaclitaxel
(30.0 g, 24.69 mmole) was added portionwise to a suspension of 10%
palladium on carbon (20% load, 6 g) in EtOH (900 ml, 200 proof) at
0.degree. C. The resulting suspension was degassed by evacuating
air and purging with argon. This process was repeated two
additional times. The argon then was replaced with hydrogen
following the above degassing procedure with vigorous stirring. The
resulting mixture was stirred at 0.degree. C. for 2 hrs. The
cooling bath was removed and the reaction solution was stirred at
ambient temperature for additional 24 hrs. The reaction mixture was
degassed by evacuating hydrogen and purging with argon three times
following the above degassing procedure. It was filtered under
argon through a pad of Celite. The filtrate was divided into two
equal portions and EtOH (190 ml, 200 proof) was added to each
portion. To one portion (.about.630 ml) was slowly added a solution
of N-methylglucamine (2.24 g, 0.94 eq) in a 1:1 mixture of
H.sub.2O:EtOH (200 proof) (20 ml) over a period of 5 minutes with
vigorous stirring. To the resulting white suspension was added
distilled water (100 ml) and the suspension was stirred for 30
minutes and then warmed to about 49.degree. C. The clear
homogeneous solution was kept in an oil bath set at 50.degree. C.,
allowed to cool down to room temperature and kept at room
temperature for 2 hrs and at 4.degree. C. for 1-1/2 hrs. It was
filtered and washed with 3% H.sub.2O in EtOH (100 ml), suction
dried at room temperature for 16 hrs to give 9.65 g (.about.64%
yield) of the title N-methylglucamine salt with homogeneity index
of 96.4%.
[0351] This material (9.65 g) was dissolved in a mixture of 15%
H.sub.2O in EtOH (.about.450 ml) at 52.degree. C. Then, the
solution was cooled down and kept at 28.degree. C. for 3-1/2 hrs,
room temperature for 16 hrs, and 4.degree. C. for 3 hrs. The
resulting crystals were filtered, washed with cold 2% H.sub.2O in
EtOH (50 ml.times.2), suction dried for 4 hrs, and then dried in
vacuo (1 mmHg) for 16 hrs to give 7.5 g (.about.80% yield) of the
title N-methylglucamine salt (homogeneity idex as determined by
HPLC was 98.6%); mp.: >154.degree. C. with decomposition.
[0352] Elemental analysis calculated for
C.sub.58H.sub.75N.sub.2O.sub.25P.- cndot.5.0 H.sub.2O: C, 52.72; H,
6.48; N, 2.12; KF (H.sub.2O), 6.82. Found: C, 53.09; H, 6.50; N,
2.08; KF (H.sub.2O), 7.12.
Example 4. 2'-O-(Phosphonooxymethyl)paclitaxel
[0353] (a) Preparation of
2'-O-(methylthiomethyl)-7-O-(triethylsilyl)pacli- taxel 56
[0354] To a cooled (0 to -5.degree. C.) solution of
7-O-(triethylsily)paclitaxel (2.46 g; 2.5439 mmol) in dry
acetonitrile (100 ml) was added dimethylsulfide (1.348 g; 1.59 ml;
21.6976 mmol) followed by benzoyl peroxide (2.628 g; 10.8488 mmol).
The heterogeneous mixture was stirred at 0.degree. C. for 1 h and
kept at 5.degree. C. for 18 h. A yellow solution was observed. This
was evaporated to dryness and purified by silica gel column
(eluting with ethyl acetate: hexane, 1:4; 1:3 and 1:2) to give the
title compound (1.0 g, 38%). This was used as such for next
step.
[0355] MS: [M+H].sup.+, 1028; [M+Na].sup.+, 1050; [M+K].sup.+,
1066
[0356] (b) Preparation of 2'-O-(methylthiomethyl)paclitaxel 57
[0357] To a cooled (-15.degree. C.) solution of the product of step
(a) (1.0 g; 0.9737 mmol) in dry acetonitrile (30 ml) was added
dropwise 0.5N HCl (3 ml). The resulting solution was stirred at
-15.degree. C. for 1 h and at 5.degree. C. for 18 h. This was
diluted with ethyl acetate (20 ml) and washed with cold 6%
NaHCO.sub.3 solution and brine. It was dried (MgSO.sub.4) and
evaporated to dryness. This was purified by silica gel plate
(methylene chloride: 15% acetonitrile) to give pure title compound
(280 mg, 31.4%).
[0358] IR(KBr): 3446, 3064, 2940, 1726, 1666, 1582, 1516,1486.
[0359] NMR (CDCl.sub.3): .delta. 1.118 (s, 3H), 1.229 (s, 3H),
1.662 (s, 3H), 1.689 (s, 3H), 1.871 (s, 3H), 2.209 (s, 3H), 2.450
(s, 3H), 3.800 (d, H), 4.119 (d, H), 4.305 (d, H), 4.413 (m, H),
4.563 (d, H), 4.703 (d, H), 4.940 (d, H), 4.958 (dd, H), 5.667 (d,
H), 5.822 (dd, H), 6.263 (m, 2H), 7.019 (d, NH), 7.293-8.127 (m,
15H).
[0360] MS: [M+H].sup.+, 914; [M+Na].sup.+, 936; [M+K].sup.+,
952
[0361] HRMS: MH.sup.+: 914.3394 (calculated=914.3422)
[0362] (c) Preparation of
2'-O-(dibenzylphosphonooxymethyl)paclitaxel 58
[0363] To a stirred solution of the product of step (b) (0.89 g;
0.9748 mmol) in dry 1,2-dichloroethane (12 ml) was added powdered
4.ANG. molecular sieves (1.0 g) followed by dropwise addition of a
solution mixture of N-iodosuccinimide (0.33 g; 1.4622 mmol) and
dibenzyl phosphate (0.41 g; 1.4622 mmol) in dry tetrahydrofuran (8
ml). The resulting mixture was stirred at room temperature for 1
h., then filtered over Celite. The filtrate was evaporated to
dryness and the red residue was taken up in ethyl acetate (50 ml)
and washed with cold 6% NaHSO.sub.3, cold 6% NaHCO.sub.3 and brine.
It was dried (MgSO.sub.4) and evaporated to give a foam. This was
purified by silica gel plate (methylene chloride:20% acetonitrile)
to give pure product (0.77 g, 69%).
[0364] IR(KBr): 3854, 3744, 3362, 3066, 1960, 1722, 1602, 1580.
[0365] NMR (CDCl.sub.3): .delta. 1.075 (s, 3H), 1.167 (s, 3H),
1.651 (s, 3H), 1.799 (s, 3H), 2.209 (s, 3H), 2.296 (s, 3H), 2.464
(m, H), 3.686 (d, H), 4.121 (d, H), 4.240 (d, H), 4.293 (m, H),
4.808-4.957, (m, 6H), 5.006 (m, H), 5.565-5.649 (m, 2H), 6.034 (t,
H), 6.194 (3, H), 7.100-8.132, (m, 26H).
[0366] MS: [M+H].sup.+, 1144; [M+Na].sup.+, 1166; [M+K].sup.+,
1182
[0367] (d) Preparation of 2'-O-(phosphonooxymethyl)paclitaxel
59
[0368] A mixture of the product of step (c) (0.9 g; 0.7874 mmol)
and 10% Pd/C (1.0 g) in ethyl acetate (20 ml) was hydrogenated at
60 psi (400 kPa) for 24 h. The reaction mixture was filtered over
Celite and the filtrate evaporated to dryness. The residue was
purified by silica gel plate (methylene chloride: 40% methanol) to
give the title product (0.254 g, 33.4%).
[0369] MP 202-205.degree. C. (d).
[0370] IR (KBr): 3438, 3066, 2942, 1722, 1652, 1602 cm.sup.-1.
[0371] NMR (acetone-d.sub.6/D.sub.2O): .delta. 1.081 (s, 6H), 1.571
(s, 3H), 1.847 (s, 3H), 2.115 (s, 3H), 2.357 (s, 3H), 3.707 (d, H),
4.08 (m, 2H), 4.275 (m, H), 4.941-5.085 (m, 4H), 5.231 (t, H),
5.430 (d, H), 5.544 (d, H), 5.970 (t, H), 6.376 (s, H), 6.961-8.017
(m, 16H).
[0372] MS: [M+Na].sup.+, 986; [M+K].sup.+, 1002; [M+2Na-H].sup.+,
1008; [M+Na+K-H].sup.+, 1024; [M+2K-H].sup.+, 1040
[0373] HRMS: MNa.sup.+, 986.2955 (Calculated=986.2976)
Example 5. 2',7-O-bis(phosphonooxymethyl)paclitaxel sodium salt
[0374] (a) Preparation of 2',7-O-bis(methylthiomethyl)paclitaxel
60
[0375] Solid benzoyl peroxide (1.995 g, 8 mmol) was added to a
stirred solution of paclitaxel (0.853 g, 1 mmol) and dimethyl
sulfide (1.465 g, 20 mmol) acetonitrile (20 mL) at 0.degree. C. The
reaction mixture was stirred vigorously at 0.degree. C. for 3
hours. Its progress was monitored by TLC in hexane:ethyl acetate
(1:1, v/v), R.sub.f paclitaxel=0.24, R.sub.f product=0.60. When
starting material disappeared (ca. after 3 hrs) the reaction was
quenched by evaporation of solvents to dryness at 25.degree. C.
using house vacuum. The dry residue was separated using silica gel
column (EM Science, 40 - 63 .mu.m), 100 mL of dry silica gel,
column size: .PHI.=3/4 in., solvent system: hexane:ethyl acetate
(3:2, v/v), volume of each fraction: ca. 25 mL. The title compound
(0.515 g, 53% yield) was recovered from fractions 15 to 19.
[0376] MS (FAB/matrix NOBA,NaI KI): [M+H].sup.+, m/z 974;
[M+Na].sup.+, m/z 996; [M+K].sup.+, m/z 1012
[0377] UV (MeOH): .lambda.max=204 nm, E(1%/1 cm)=243.45;
.lambda.max=228 nm, E(1%/1 cm)=313.99
[0378] IR (KBr): 3440, 3064, 2926, 1724, 1668, 1602, 1582, 1514,
1484, 1452, 1372, 1314, 1266, 1242, 1178, 1142, 1068, 1026, 990,
916, 886, 848, 800, 774, 710, 646, 606, 570, 540, 480
cm.sup.-1.
[0379] .sup.1H-NMR (CDCl.sub.3) .delta.: 1.17 (3H, s), 1.20 (3H,
s), 1.68 (3H, s), 1.74 (3H, s), 1.84 (H, dd), 2.04 (3H, d), 2.09
(3H, s), 2.15 (3H, s) overlaps with (H, m), 2.37 (H, dd), 2.51 (3H,
s), 2.79 (H, ddd), 3.78 (H, d), 4.18 (H, d), 4.28 (H, m), 4.31 (H,
d), 4.53 - 4.74 (4H, two overlapping AB m), 4.93 (H,d), 4.95 (H,
d), 5.68 (H, d), 5.82 (H, dd), 6.24 (H, dd), 6.54 (H, s), 7.05 (H,
d), 7.28 - 7.59 (10H, overlapping m), 7.57 (H, m), 7.76 (2H, d),
8.09 (2H, d).
[0380] (b) Preparation of
2',7-O-bis(dibenzylphosphonooxymethyl)paclitaxel 61
[0381] A solution of N-iodosuccinimide, (135 mg, 0.5 mmol) and
dibenzylphosphate, (167 mg, 0.5 mmol) in dry tetrahydrofuran (8 mL)
was added to a mixture of 2',7-O-bis(methylthiomethyl)paclitaxel
(198 mg, 0.2 mmol) and 5 .ANG. molecular sieves (ca. 200 mg) in
methylene chloride (12 mL) at room temperature. The reaction
mixture was stirred for 1.5 hours, then the molecular sieves were
filtered off on celite, washed with methylene chloride (10 mL) and
the solvents were evaporated to dryness at room temperature using
house vacuum. The residue was dissolved in ethyl acetate (100 ml)
and washed in a separation funnel with 1% sodium thiosulfate (50
mL), with 0.5 m sodium bicarbonate (50 mL), and twice with water
(2.times.50 mL). The organic phase was dried over magnesium
sulfate, evaporated to dryness and re-dissolved in ethyl acetate (1
mL). The product was precipitated with 50 mL of ethyl ether:hexane
(1:1) and washed twice with the same solvent system (2.times.50
mL). A crude product (218 mg) was obtained in 74% yield.
Purification of this product was performed by loading its methylene
chloride solution (3 mL) on silica gel (.PHI.=3/4 in..times.L=1
in.) and eluting the product with 50 mL of methylene chloride:ethyl
acetate (3:1) solvent system. The title compound (172.7 mg) was
obtained in 59.3% yield.
[0382] MS (FAB, matrix NOBA/NaI, KI): [M+Na].sup.+, m/z 1456;
[M+K].sup.+, m/z 1472
[0383] UV (MeCN): .lambda.max=194 nm, E(1%/1 cm)=1078.36;
.lambda.max=228 nm, E(1%/1 cm)=311.95
[0384] IR (KBr): 3430, 3066, 3032, 2958, 1744, 1726, 1664, 1602,
1582, 1532, 1488, 1456, 1372, 1270, 1244, 1158, 1108, 1068, 1016,
1000, 952, 886, 800, 776, 738, 698, 604, 498 cm.sup.-1.
[0385] .sup.1H-NMR (CDCl.sub.3) .delta.: 1.12 (3H, s), 1.14 (3H,
s), 1.56 (H, m), 1.67 (3H, s), 1.84 (3H, d), 1.90 (H, m), 2.17 (3H,
s), 2.29 (3H, s), 2.73 (H, m), 3.73 (H, d), 4.08 (H, d), 4.15 (H,
m), 4.20 (H, d), 4.77 (H, m), 4.79 (H, d), 4.91 - 5.04 (10H
overlapping m), 5.25 (H, dd), 5.38 (H, dd), 5.54 - 5.64 (2H,
overlapping m), 5.99 (H, br. dd), 6.25 (H, s), 7.11 - 7.14 (2H, m),
7.24 - 7.64 (28H, overlapping m), 7.94 (2H, dd), 8.04 (2H, dd),
8.30 (H, d).
[0386] (c) Preparation of 2',7-O-bis(phosphonooxymethyl)paclitaxel
sodium salt 62
[0387] A sample of 2',7-O-bis(dibenzylphosphonooxymethyl)paclitaxel
(112 mg, 0.078 mmol) was dissolved in ethyl acetate (7 ml) and
hydrogenated over 10% palladium on charcoal (50 mg) at room
temperature, 60 PSI (400 kPa), for 2 hours. The catalyst was
removed by filtration over Celite. The Celite was rinsed with ethyl
acetate (10 mL). The filtrate was treated with solid sodium
bicarbonate (20 mg, 3 eq.) and then the solvent was evaporated to
dryness. A dry residue was re-dissolved in 5 mL of water:acetone
(4:1, v/v) and purified by C-18 reverse phase column chromatography
(55 - 105.mu. C-18, Waters, 50 mL of dry C-18, .PHI.=3/4 in. in
water: acetone (4:1, v/v). Eluant was monitored on analytical HPLC
Jones C-18 column (15 cm, 1 mL/min., .lambda.=230 mn) in
acetonitrile:phosphate buffer pH 6 (50/50, v/v) with the addition
of Q12 ion pair cocktail (Regis), Rt=4.7 min. Fractions containing
the title product were combined, acetone was evaporated under house
vacuum at 20.degree. C., and the solution was lyophilized. The
title product (44.2 mg) was obtained in 58.8% yield.
[0388] MS (FAB,matrix NOBA/NaI, KI): [M+H].sup.+, m/z 1118;
[M+Na].sup.+, m/z 1140
[0389] UV (MeCN): .lambda.max=192 nm, E(1%/1 cm)=129.73;
.lambda.max=230 nm, E(1%/1 cm)=26.43
[0390] IR (KBr): 3430, 3066, 2956, 1724, 1658, 1604, 1582, 1520,
1486, 1452, 1374, 1316, 1256, 1152, 1110, 1070, 1026, 966, 914,
802, 772, 710, 538 cm.sup.-1.
[0391] .sup.1H-NMR (acetone-d.sub.6/D.sub.2O) .delta.: 0.97 (3H,
s), 1.02 (3H, s), 1.47 (H, m), 1.54 (3H, s), 1.70 (H, m), 1.75 (3H,
s), 1.85 (H, m), 2.11 (3H, s), 2.30 (3H, s), 2.88 (H, m), 3.64 (H,
d), 4.03 (H, m), 4.06 (H, d), 4.16 (H, d), 4.74 (H, m), 4.86 (H,
m), 5.11 (H, br. t), 5.22 (H, d), 5.42 (H, d), 5.90 (H, br. t),
6.21 (H, s), 7.06 (H, br.t), 7.32 - 7.69 (10H, ovelapping m), 7.80
(2H, d), 7.93 (2H, d).
Example 6. 7-O-methylthiomethylbaccatin III (7-MTM baccatin
III)
[0392] 63
[0393] To a solution of
2'-O-ethyloxycarbonyl-7-O-methylthiomethylpaclitax- el (compound of
Example 3(b), 27 g, 27.4 mmol) in 100 mL of THF and 500 mL of
methanol was added freshly ground K.sub.2CO.sub.3 (2.7 g, 19 mmol).
The solution was stirred for 30 minutes and neutralized with IR-120
(H.sup.+) resin, filtered and concentrated. The crude filtrate was
then dissolved in 200 mL of dichloromethane and stirred for 24
hours with tetrabutylammonium borohydride (10 g). The solution was
diluted with dichloromethane and washed with water, saturated
bicarbonate and brine. The organic fraction was then dried over
MgSO.sub.4 and concentrated. The residue was chromatographed over
silica gel (1:1 hexane/ethyl acetate) to give 9.4 g of the title
compound (53%) with a melting point of 269.degree. C.
[0394] FABMS (NOBA) M+H calcd for C.sub.33H.sub.43SO.sub.11: 647.
Found: 647.
[0395] IR(KBr) 3474, 1746, 1724, 1712, 1270, 1240, 1070
cm.sup.-1
[0396] .sup.1H NMR (CDCl.sub.3, 300 MHz) .delta. 8.08 (d, J=7.1 Hz,
2H), 7.58 (t, J=7.5 Hz, 1H), 7.45 (t, J=7.8 Hz, 2H), 6.55 (s, 1H),
4.94 (d, J=8.1 Hz, 1H), 4.83 (bq, J=5.1 Hz, 1H), 4.66 (ABq,
J=14.7,12.3 Hz, 2H), 4.30 (m, 2H), 4.13 (d, J=8.4 Hz, 1H), 3.91 (d,
J=6.6 Hz, 1H), 2.79 (m, 1H), 2.27 (s, 3H), 2.25 (m, 2H), 2.19 (s,
3H), 2.16 (s, 3H), 2.10 (s, 4H), 1.81 (m, 1H), 1.72 (s, 3H), 1.61
(m, 2H), 1.16 (s, 3H), 1.03 (s, 3H).
[0397] .sup.13C NMR (CDCl.sub.3, 75.5 Hz) .delta. 202.3, 170.8,
169.3, 167.0, 144.2, 132.6, 132.1, 130.1, 129.4, 128.6, 83.9, 80.9,
78.7, 75.7, 74.5, 73.9, 67.9, 57.6, 47.6, 42.7, 38.3, 26.7, 22.6,
21.0, 20.1, 15.2, 15.0, 10.8.
Example 7.
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarbonyl)-3'-(2-fur-
yl)-2'-O-ethyloxycarbonyl-7-O-phosphonooxymethylpaclitaxel
triethanolamine salt
[0398] (a) preparation of
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarb-
onyl)-3'-(2-furyl)-7-O-methylthiomethylpaclitaxel 64
[0399] To a solution of HMDS (0.40 mL, 1.90 mmol) in 15 mL of THF
was added a solution of n-BuLi (0.75 mL, 2.5M in hexanes, 1.88
mmol) and stirred 5 minutes at -55.degree. C. To this solution was
added 7-MTM baccatin III (compound of example 6, 1.03 g, 1.59 mmol)
in 10 mL of THF and stirred for 10 minutes before addition of an 10
mL solution of
(3R,4R)-1-(t-butyloxycarbonyl)-4-(2-furyl)-3-(triethylsilyloxy)-2-azetidi-
none (883 mg, 2.40 mmol). The cold bath was removed and replaced
with a 0.degree. C. bath and the reaction mixture was stirred for
30 minutes. The solution was diluted with ethyl acetate and washed
with saturated NH.sub.4Cl solution, dried over MgSO.sub.4 and
concentrated. The residue was chromatographed over silica gel
(2.5:1 hexane/ethyl acetate) to give 1.5 g of the coupling product
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butylox-
ycarbonyl)-3'-(2-furyl)-7-O-methylthiomethyl-2'-O-triethylsilylpaclitaxel
(93%).
[0400] FABMS (NOBA) M+Na calcd for C.sub.50H.sub.71NSSiO.sub.16:
1036. Found: 1036.
[0401] IR(film) 3446 (s), 1720, 1368, 1242, 1166, 1144, 1124, 1066
cm.sup.-1
[0402] .sup.1H NMR (CDCl.sub.3, 300 MHz) .delta. 8.07 (d, J=7.2 Hz,
2H), 7.56 (m, 1H), 7.46 (t, J=7.5 Hz, 2H), 7.36 (m, 1H), 6.56 (s,
1H), 6.33 (m, 1H), 6.20 (m, 2H), 5.67 (d, J=6.9 Hz, 1H), 5.29 (bs,
2H), 4.94 (d, J=7.8 Hz, 1H), 4.75 (s, 1H), 4.65 (s, 2H), 4.28 (m,
2H), 4.16 (d, J=8.1 Hz, 1H), 3.89 (d, J=6.9 Hz, 1H), 2.80 (m, 1H),
2.46 (s, 3H), 2.37 (m, 1H), 2.22 (m, 1H), 2.16 (s, 3H), 2.10 (s,
3H), 2.04 (s, 3H), 1.84 (m, 1H), 1.74 (s, 3H), 1.65 (m, 1H), 1.33
(s, 9H), 1.20 (s, 3H), 1.19 (s, 3H), 0.81 (t, J=7.8 Hz, 9H), 0.47
(m, 6H).
[0403] .sup.13C NMR (CDCl.sub.3, 75.5 Hz) .delta. 202.0, 171.2,
170.3, 169.3, 167.1, 155.3, 152.0, 141.9, 141.0, 133.6, 132.9,
130.2, 129.2, 128.7, 110.7, 107.3, 84.0, 81.1, 80.2, 78.7, 76.1,
75.7, 74.7, 74.1, 72.4, 71.1, 57.4, 52.8, 47.1, 43.3, 35.2, 33.0,
28.1, 26.3, 22.9, 21.2, 21.0, 15.0, 14.5, 10.9, 6.5, 4.3.
[0404] To a solution of the 2'-triethylsilyl ether obtained above
(330 mg, 0.32 mmol) in 7 mL of THF was added tetrabutylammonium
fluoride (0.35 mL, 1.0M in THF, 0.35 mmol) and stirred 10 minutes.
The solution was diluted with ethyl acetate and washed with brine,
dried over MgSO.sub.4 and concentrated and the residue was
chromatographed over silica gel (2:1 hexane/ethyl acetate) to give
301 mg of the title compound (95%).
[0405] FABMS (NOBA) M+H calcd for C.sub.45H.sub.58NO.sub.16S: 900.
Found: 900.
[0406] IR(film) 3442, 1720, 1242, 1066, 1026 cm.sup.-1
[0407] .sup.1H NMR (CDCl.sub.3, 300 MHz) .delta. 8.07 (d, J=7.3 Hz,
2H), 7.57 (t, J=7.3 Hz, 1H), 7.45 (t, J=7.8 Hz, 2H), 7.38 (s, 1H),
6.53 (s, 1H), 6.34 (d, J=3.2 Hz, 1H), 6.29 (d, J=3.2 Hz, 1H), 6.17
(t, J=8.1 Hz, 1H), 5.65 (d, J=6.9 Hz, 1H), 5.29 (m, 2H), 4.92 (d,
J=8.0 Hz, 1H), 4.70 (m, 1H), 4.64 (d, J=4.6 Hz, 2H), 4.29 (m, 2H),
4.14 (d, J=8.3 Hz, 1H), 3.86 (d, J=6.8 Hz, 1H), 3.37(d, J=5.8 Hz,
1H), 2.77 (m, 1H), 2.38 (s, 3H), 2.32 (m, 2H), 2.16 (s, 3H), 2.10
(s, 3H), 2.02 (s, 3H), 1.77 (m, 3H), 1.73 (s, 3H), 1.33 (s, 9H),
1.17 (s, 3H), 1.12 (s, 3H).
[0408] .sup.13C NMR (CDCl.sub.3, 75.5 Hz) .delta. 202.0, 172.6,
170.3, 169.2, 167.0, 155.2, 151.3, 142.4, 140.4, 133.7, 133.2,
130.2, 129.1, 128.7, 110.7, 107.4, 83.9, 81.2, 80.5, 78.6, 76.5,
76.1, 75.4, 74.6, 74.0, 72.5, 71.8, 57.4, 51.7, 47.2, 43.2, 35.2,
32.8, 28.1, 26.4, 22.6, 20.9, 15.2, 14.6, 10.9, 8.3.
[0409] (b) preparation of
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarb-
onyl)-3'-(2-furyl)-2'-O-ethyloxycarbonyl-7-O-methylthiomethylpaclitaxel
65
[0410] To a solution of the product of step (a) (864 mg, 0.96 mmol)
in 50 mL of dichloromethane at 0.degree. C. was added
diisopropylethyl amine (2.0 mL, 11.5 mmol) and ethyl chloroformate
(0.50 mL, 5.25 mmol) and stirred for 4 hours. The solution was
diluted with dichloromethane and washed with saturated bicarbonate
and dried over MgSO.sub.4 and concentrated. The residue was
chromatographed over silica gel (1:1 hexane/ethyl acetate) to give
884 mg of the 2' ethyl carbonate title compound (95%).
[0411] FABMS (NOBA) M+H calcd for C.sub.48H.sub.62NO.sub.18S
972.3688. Found: 972.3654.
[0412] IR(film) 1752, 1720, 1370, 1244, 1196, 1176, 1064
cm.sup.-1
[0413] .sup.1H NMR (CDCl.sub.3, 300 MHz) .delta. 8.09 (d, J=7.8 Hz,
2H), 7.57 (t, J=7.5 Hz, 1H), 7.46 (t, J=7.8 Hz, 2H), 7.38 (s, 1H),
6.55 (s, 1H), 6.35 (m, 1H), 6.27 (m, 1H), 6.22 (t, J=7.8 Hz, 1H),
5.67 (d, J=7.2 Hz, 1H), 5.51 (d, J=9.9 Hz, 1H), 5.34 (d, J=2.4 Hz,
1H), 5.25 (d, J=10.2 Hz, 1H), 4.95 (d, J=8.1 Hz, 1H), 4.65 (s, 2H),
4.30 (m, 2H), 4.22 (m, 2H), 3.88 (d, J=7.2 Hz, 1H), 2.81 (m, 1H),
2.41 (s, 3H), 2.36 - 2.21 (m, 2H), 2.16 (s, 3H), 2.11 (s, 3H), 2.09
(s, 3H), 1.83 (m, 1H), 1.74 (s, 3H), 1.67 (s, 1H), 1.59 (s, 1H),
1.34 (s, 9H), 1.29 (t, J=7.2 Hz, 3H), 1.20 (s, 3H), 1.18 (s,
3H).
[0414] .sup.13C NMR (CDCl.sub.3, 75.5 Hz) .delta. 202.1, 169.9,
169.1, 167.6, 167.0, 154.0, 150.1, 142.6, 141.0, 133.6, 132.9,
130.2, 129.2, 128.7, 110.7, 107.5, 83.9, 81.1, 80.7, 78.7, 76.0,
75.7, 75.1, 74.7, 74.2, 71.8, 65.1, 57.4, 49.7, 47.1, 43.2, 35.0,
33.0, 28.1, 26.3, 22.6, 21.1, 20.9, 15.1, 14.5, 14.1, 10.9.
[0415] (c) preparation of
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarb-
onyl)-3'-(2-furyl)-2'-O-ethyloxycarbonyl-7-O-dibenzylphosphonooxymethylpac-
litaxel 66
[0416] To a solution of the product of step (b) (230 mg, 0.236
mmol) in 10 mL of anhydrous THF was added 300 mg of 4 A sieves,
dibenzylphosphate (270 mg, 0.98 mmol) and recrystallized NIS (62
mg, 0.28 mmol). To this solution was added silver
trifluoromethanesulfonate (45 mg, 0.17 mmol) and the solution
stirred for 3 hours. The solution was filtered through Celite and
diluted with ethyl acetate and washed with 10% NaS.sub.2O.sub.8,
sautruated bicarbonate, and brine, dried over MgSO.sub.4 and
concentrated. The residue was chromatographed over silica gel (15%
acetonitrile/chloroform) to give 219 mg of the dibenzyl phosphate
title compound (77%).
[0417] FABMS (NOBA) M+Na calcd for C.sub.61H.sub.72NPO.sub.22Na
1224. Found: 1224.
[0418] IR(film) 3422 (br), 1750, 1722, 1370, 1244, 1160, 1036,
1016, 1000, 976, 944 cm.sup.-1
[0419] .sup.1H NMR (CDCl.sub.3, 300 MHz) .delta. 8.08 (d, J=6.9 Hz,
2H), 7.58 (t, J=7.2 Hz, 1H), 7.46 (t, J=7.8 Hz, 2H), 7.39 (s, 1H),
7.31 (m, 10), 6.35 (m, 2H), 6.28 (s, 1H), 6.21 (t, J=7.8 Hz, 1H),
5.64 (d, J=6.9 Hz, 1H), 5.50 (d, J=10.5 Hz, 1H), 5.39 (d, J=6.6 Hz,
1H), 5.32 (d, J=2.4 Hz, 1H), 5.25 (d, J=9.9 Hz, 1H), 5.01 (dd,
J=8.1, 6.3 Hz, 5H), 4.86 (d, J=8.4 Hz, 1H), 4.29-4.09 (m, 4H), 3.85
(d, J=6.9 Hz, 1H), 2.77 (m, 1H), 2.40 (s, 3H), 2.30 (m, 2H), 2.16
(s, 3H), 1.99 (s, 3H), 1.94 (m, 1H), 1.70 (s, 3H), 1.67 (s, 1H),
1.54 (s, 1H), 1.34 (s, 9H), 1.28 (t, J=7.2 Hz, 3H), 1.20 (s, 3H),
1.17 (s, 3H).
[0420] .sup.13C NMR (CDCl.sub.3, 75.5 Hz) .delta. 201.8, 169.9,
169.2, 167.7, 167.0, 155.1, 154.0, 150.0, 142.74, 141.1, 133.7,
132.9, 130.2, 129.1, 128.7, 128.5, 128.4, 128.0, 110.7, 107.6,
93.8, 84.1, 81.6, 80.8, 80.7, 78.8, 76.3, 75.1, 74.6, 71.8, 69.3,
69.2, 65.1, 57.0, 49.7, 46.7, 43.2, 35.0, 28.1, 26.4, 22.6, 21.2,
20.8, 14.6, 14.1, 10.5.
[0421] (d) preparation of
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarb-
onyl)-3'-(2-furyl)-2'-O-ethyloxycarbonyl-7-O-phosphonooxymethylpaclitaxel
triethanolamine salt 67
[0422] To a solution of the product of step (c) (311 mg, 0.259
mmol) in 25 mL of ethyl acetate was added 60 mg of Pd on carbon
(10%) and the solution stirred under an atmosphere of H.sub.2 for
30 minutes. The catalyst was removed by filtratation through Celite
and the filtrate concentrated in vacuo. The residue was dissolved
in 3 mL of ethyl acetate and triethananolamine added (2.3 mL, 0.1M
in ethyl acetate, 0.23 mmol). The solution was concentrated and the
residue was chromatographed over C.sub.18 (40% acetonitrile/water)
and lyophilized to give 205 mg of the phosphate triethanolamine
salt (67%).
[0423] FABMS (NOBA) M+Na calcd for C.sub.47H.sub.60HPO.sub.22Na
1044. Found: 1044.
[0424] IR(film) 3432 (br), 1752, 1722, 1372, 1246, 1158, 1108,
1096, 1070, 1002 cm.sup.-1
[0425] .sup.1H NMR (d.sub.6 acetone/D.sub.2O, 300 MHz) .delta. 8.09
(d, J=7.2 Hz, 2H), 7.62 (m, 2H), 7.52 (t, J=7.5 Hz, 2H), 6.48 (d,
J=3.3 Hz, 1H), 6.42 (m, 2H), 6.16 (t, J=8.7 Hz, 1H), 5.65 (d, J=6.9
Hz, 1H), 5.46 (d, J=3.6 Hz, 1H), 5.30 (d, J=3.6 Hz, 1H), 5.17 (bs,
1H), 5.01 (bd, J=9.0 Hz, 1H), 4.19 (bs, 1H), 4.18 (m, 5H), 3.95 (m,
4H), 3.87 (d, J=6.9 Hz, 1H), 3.68 (s, 1OH), 3.50 (bt, J=4.8 Hz,
4H), 2.95 (m, 1H), 2.44 (s, 3H), 2.41 (m, 2H), 2.16 (s, 3H), 1.99
(s, 3H), 1.94 (m, 1H), 1.68 (s, 3H), 1.34 (s, 9H), 1.24 (t, J=6.9
Hz, 3H), 1.17 (s, 6H).
Example 8.
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarbonyl)-3'-(2-thi-
enyl)-2'-O-ethyloxycarbonyl-7-O-phosphonooxymethylpaclitaxel
triethanolamine salt
[0426] (a) preparation of
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarb-
onyl)-3'-(2-thienyl)-7-O-methylthiomethylpaclitaxel 68
[0427] To a solution of HMDS (0.5 mL, 2.4 mmol) in 18 mL of THF at
-55.degree. C. was added n-BuLi (0.85 mL, 2.5M in hexanes, 2.1
mmol). After 10 minutes 7-MTM baccatin III (1.15 g, 1.78 mmol) in
18 mL of THF was added dropwise and stirred in the cold for 10
minutes.
(.+-.)cis-1-(t-Butyloxycarbonyl)-4-(2-thienyl)-3-(triethylsilyloxy)-2-aze-
tidinone (2.80 g, 7.3 mmol) in 18 mL of THF was added and the cold
bath allowed to slowly warm to 0.degree. C. over 30 minutes. The
solution was diluted with ethyl acetate and washed with saturated
NH.sub.4Cl solution, dried over MgSO.sub.4 and concentrated. The
residue was chromatographed over silica gel (5:1 hexane/ethyl
acetate) to give 1.87 g of recovered lactam (3:1 hexane/ethyl
acetate) to give 1.44 g of the coupling product
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarbonyl)-3'-(2-thienyl)-7-O--
methylthiomethyl-2-O-triethylsilylpaclitaxel (78%).
[0428] FABMS (NOBA) M+Na calcd for
C.sub.51H.sub.71NO.sub.15S.sub.2SiNa 1052. Found: 1052.
[0429] IR(film) 3442 (br), 1720, 1490, 1368, 1270, 1242, 1162,
1110, 1064, 1024, 984, 754 cm.sup.-1
[0430] .sup.1H NMR (CDCl.sub.3, 300 MHz) .delta. 8.09 (d, J=7.2 Hz,
2H), 7.57 (t, J=7.6 Hz, 1H), 7.47 (t, J=7.8 Hz, 2H), 7.22 (m, 1H),
6.95 (m, 2H), 6.55 (s, 1H), 6.21 (t, J=9.3 Hz, 1H), 5.68 (d, J=6.9
Hz, 1H), 5.49 (bd, 1H), 5.39 (bd, J=9.6 Hz, 1H), 4.94 (d, J=7.8 Hz,
1H), 4.65 (s, 2H), 4.57 (s, 1H), 4.28 (m, 2H), 4.17 (d, J=8.4 Hz,
1H), 3.88 (d, J=6.9 Hz, 1H), 2.80 (m, 1H), 2.46 (s, 3H), 2.37 (m,
1H), 2.20 (m, 1H), 2.17 (s, 3H), 2.10 (s, 3H), 2.03 (s, 3H), 1.84
(m, 1H), 1.74 (s, 3H), 1.68 (s, 1H), 1.62 (S, 1H), 1.31 (s, 9H),
1.20 (s, 6H), 0.84 (t, J=7.8 Hz, 9H), 0.50 (m, 6H).
[0431] .sup.13C NMR (CDCl.sub.3, 75.5 Hz) .delta. 201.9, 171.1,
170.7, 170.1, 169.3, 167.0, 155.1, 142.8, 140.9, 133.6, 132.9,
130.2, 129.2, 128.7, 126.9, 124.6, 83.9, 81.2, 80.1, 78.8, 77.4,
76.0, 75.7, 75.2, 74.8, 74.1, 71.3, 57.4, 53.8, 47.0, 43.3, 35.3,
33.3, 28.1, 26.3, 23.0, 21.3, 20.9, 14.9, 14.4, 10.9, 6.6, 4.5.
[0432] To a solution of the 2'-triethylsilyl ether obtained above
(1.41 g, 1.37 mmol) in 14 mL of THF was added tetrabutylammonium
fluoride (1.4 mL, 1.0M in THF, 1.40 mmol). The solution was stirred
for 30 minutes, diluted with ethyl acetate and washed with brine,
dried over MgSO.sub.4 and concentrated. The residue was
chromatographed over silica gel (1:1 hexane/ethyl acetate) to give
1.16 g of the title compound (92%).
[0433] FABMS (NOBA) M+Na calcd for
C.sub.45H.sub.57NO.sub.15S.sub.2Na 938. Found: 938.
[0434] IR(film) 3440 (br), 1720, 1368, 1242, 1168, 1106, 1066, 710
cm.sup.-1
[0435] .sup.1H NMR (CDCl.sub.3, 300 MHz) .delta. 8.08 (d, J=7.2 Hz,
2H), 7.59 (m, 1H), 7.47 (t, J=7.8 Hz, 2H), 7.24 (m, 1H), 7.07 (m,
1H), 6.99 (m, 1H), 6.53 (s, 1H), 6.18 (t, J=8.1 Hz, 1H), 5.66 (d,
J=6.9 Hz, 1H), 5.49 (d, J=9.6 Hz, 1H), 5.32 (d, J=9.6 Hz, 1H), 4.92
(d, J=7.8 Hz, 1H), 4.63 (m, 3H), 4.28 (m, 2H), 4.15 (d, J=8.4 Hz,
1H), 3.86 (d, J=6.9 Hz, 1H), 3.47 (d, J=5.4 Hz, 1H), 2.78 (m, 1H),
2.36 (s, 3H), 2.34 (, 2H), 2.17 (s, 3H), 2.10 (s, 3H), 2.00 (s,
3H), 1.83 (m, 1H), 1.74 (s, 3H), 1.72 (s, 1H), 1.61 (s, 1H), 1.33
(s, 9H), 1.21 (s, 3H), 1.18 (s, 3H).
[0436] .sup.13C NMR (CDCl.sub.3, 75.5 Hz) .delta. 201.9,172.3,
170.3, 169.2, 167.0, 154.0, 141.5, 140.2, 133.7, 133.3, 130.2,
129.1, 128.7, 127.0, 125.4, 125.4, 83.9, 81.3, 80.4, 78.6, 76.1,
75.4, 74.5, 74.0, 73.4, 72.5, 57.5, 52.8, 47.2, 43.2, 35.3, 32.9,
28.2, 26.4, 22.6, 20.9, 15.1, 14.7, 10.8.
[0437] (b) preparation of
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarb-
onyl)-3'-(2-thienyl)-2'-O-ethyloxycarbonyl-7-O-methylthiomethylpaclitaxel
69
[0438] To a solution of the product of step (a) (621 mg, 0.677
mmol) in 35 mL of dichloromethane at 0.degree. C. was added
diisopropylethyl amine (1.20 mL, 6.89 mmol) and ethyl chloroformate
(0.35 mL, 3.7 mmol) and stirred for 1 hour. The cold bath was
removed and the solution stirred for 2 hours and was diluted with
dichloromethane and was washed with saturated bicarbonate and dried
over MgSO.sub.4 and concentrated. The residue was chromatographed
over silica gel (1:1 hexane/ethyl acetate) to give 528 mg of the
title compound (79%).
[0439] FABMS (NOBA) M+Na calcd for
C.sub.48H.sub.61NO.sub.17S.sub.2Na 1010. Found: 1010.
[0440] IR(film) 3510, 3440, 1752, 1720, 1370, 1244, 1198, 1170,
1026, 988, 756 cm.sup.-1
[0441] .sup.1H NMR (CDCl.sub.3, 300 MHz) .delta. 8.09 (d, J=7.2 Hz,
2H), 7.58 (m, 1H), 7.48 (t, J=7.8 Hz, 2H), 7.26 (m, 1H), 6.99 (,
2H), 6.55 (s, 1H), 6.23 (t, J=9.0 Hz, 1H), 5.68 (d, J=6.9 Hz, 2H),
5.33 (d, J=9.9 Hz, 1H), 5.25 (d, J=2.4 Hz, 1H), 4.94 (d, J=7.8 Hz,
1H), 4.65 (s, 2H), 4.33-4.08 (m, 5H), 3.88 (d, J=6.9 Hz, 1H), 2.80
(m, 1H), 2.40 (s, 3H), 2.40 - 2.20 (m, 2H), 2.16 (s, 3H), 2.11 (s,
3H), 2.07 (s, 3H), 1.83 (m, 1H), 1.74 (s, 3H), 1.69 (s, 1H), 1.60
(s, 1H), 1.33 (s, 9H), 1.31 (t, J=7.2 Hz, 9H), 1.20 (s, 3H), 1.19
(s, 3H).
[0442] .sup.13C NMR (CDCl.sub.3, 75.5 Hz) .delta. 202.0, 169.7,
169.1, 167.5, 167.1, 154.0, 140.9, 133.6, 132.9, 130.2, 129.2,
128.7, 127.2, 125.4, 125.3, 83.9, 81.2, 80.6, 78.8, 76.9, 76.0,
75.7, 74.7, 74.2, 72.8, 72.0, 65.2, 57.4, 50.9, 47.1, 43.3, 35.1,
33.0, 28.1, 26.4, 22.7, 21.2, 20.9, 15.1, 14.5, 14.1, 10.9.
[0443] (c) preparation of
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarb-
onyl)-3'-(2-thienyl)-2'-O-ethyloxycarbonyl-7-O-dibenzylphosphonooxymethylp-
aclitaxel 70
[0444] To a solution of the product of step (b) (516 mg, 0.522
mmol) in 15 mL of anhydrous THF was added 530 mg of 4 A sieves,
dibenzylphosphate (576 mg, 2.09 mmol) and recrystalized NIS (136
mg, 0.604 mmol). To this solution was added silver
trifluoromethanesulfonate (50 mg, 0.194 mmol) and the solution
stirred for 1 hour. The solution was filtered through Celite and
diluted with ethyl acetate and washed with 10% NaS.sub.2O.sub.8,
saturated bicarbonate and brine, dried over MgSO.sub.4 and
concentrated. The residue was chromatographed over silica gel (15%
acetonitrile/chloroform) to give 535 mg of the title compound
(84%).
[0445] FABMS (NOBA) M+Na calcd for C.sub.61H.sub.72NO.sub.21PSNa
1240. Found: 1240.
[0446] IR(film) 3424 (br), 1750, 1722, 1370, 1244, 1016, 1000, 944
cm.sup.-1
[0447] .sup.1H NMR (CDCl.sub.3, 300 MHz) .delta. 8.08 (d, J=7.0 Hz,
2H), 7.58 (m, 1H), 7.47 (t, J=7.5.Hz, 2H), 7.28 (m, 11H), 6.99 (m,
2H), 6.33 (s, 1H), 6.22 (t, J=7.8 Hz, 1H), 5.66 (m, 2H), 5.39 (t,
J=6.6 Hz, 1H), 5.34 (d, J=12 Hz, 1H), 5.22 (d, J=2.4 Hz, 1H), 5.01
(dd, J=8.1, 6.0 Hz, 5H), 4.86 (d, J=7.8 Hz, 1H), 4.29-4.08 (m, 5H),
3.85 (d, J=6.6 Hz, 1H), 2.76 (m, 1H), 2.39 (s, 3H), 2.35-2.18 (m,
2H), 2.16 (s, 3H), 1.97 (s, 4H), 1.69 (s, 4H), 1.33 (s, 9H), 1.30
(t, J=7.2 Hz, 3H), 1.20 (s, 3H), 1.17 (s, 3H).
[0448] .sup.13C NMR (CDCl.sub.3, 75.5 Hz) .delta. 197.4, 165.4,
164.9, 163.3, 162.7, 150.6, 149.7, 136.7, 136.0, 129.4, 128.6,
125.9, 124.7, 124.3, 124.2, 124.1, 123.6, 122.9, 121.1, 121.0,
89.4, 79.8, 77.3, 76.5, 76.3, 74.4, 72.0, 70.7, 70.3, 67.7, 64.9,
64.9, 60.9, 52.7, 46.5, 42.3, 38.9, 30.7, 23.8, 22.0, 18.3, 17.0,
16.4, 10.3, 9.8, 6.2.
[0449] (d) preparation of
3'-N-debenzoyl-3'-desphenyl-3'-N-(t-butyloxycarb-
onyl)-3'-(2-thienyl)-2'-O-ethyloxycarbonyl-7-O-phosphonooxymethylpaclitaxe-
l triethanolamine salt 71
[0450] To a solution of the product of step (c) (512 mg, 0.42 mmol)
in 30 mL of ethyl acetate was added 53 mg of Pd on carbon (10%) and
the solution stirred under an atmosphere of H.sub.2 for 3 hours.
The catalyst was removed by filtratation through Celite and the
filtrate concentrated in vacuo. The residue was dissolved in 2 mL
of ethyl acetate and triethananolamine added (4.0 mL, 0.1M in ethyl
acetate, 0.40 mmol). The solution was concentrated and the residue
was chromatographed over C.sub.18 (40% acetonitrile/water) and
lyophilized to give 280 mg of the phosphate triethanolamine salt
(56%). HPLC analysis showed the purity of the salt to be 96%.
[0451] FABMS (NOBA) M+Na calcd for C.sub.47H.sub.60NO.sub.21PS
1060. Found: 1060.
[0452] IR(KBr) 3422 (br), 1750, 1720, 1372, 1246, 1162, 1096, 1068,
1000 cm.sup.-1
[0453] .sup.1H NMR (d.sub.6acetone/D.sub.2O, 300 MHz) .delta. 8.06
(d, J=7.2 Hz, 2H), 7.63 (t, J=7.2 Hz, 1H), 7.52 (t, J=7.8 Hz, 2H),
7.38 (d, J=4.2 Hz, 1H), 7.16 (d, J=3.5 Hz, 1H), 7.01 (dd, J=5.1,
3.6 Hz, 1H), 6.37 (s, 1H), 6.11 (t, J=8.7 Hz, 1H), 5.61 (d, J=6.9
Hz, 1H), 5.60 (s, 1H), 5.26 (d, J=4.5 Hz, 1H), 5.14 (t, J=6.6 Hz,
1H), 5.00 (d, J=8.4 Hz, 1H), 4.86 (dd, J=12.0, 6.3 Hz, 1H), 4.17
(m, 5H), 4.00 (s, 7H), 3.92 (t, J=4.8 Hz, 6H), 3.84 (d, J=6.9 Hz,
1H), 3.48 (t, J=5.4 Hz, 6H), 2.94 (m, 1H), 2.42 (s, 3H), 2.36 (m,
1H), 2.27 (m, 1H), 2.15 (s, 3H), 1.95 (s, 4H), 1.66 (s, 3H), 1.30
(s, 9H), 1.23 (t, J=7.2 Hz, 3H), 1.14 (s, 6H).
Example 9.
10-Desacetyl-3'-N-desbenzoyl-3-N-(t-butyloxycarbonyl)-10-O-(pho-
sphonooxymethyl)paclitaxel
[0454] (a) preparation of
10-desacetyl-10-O-benzyloxycarbonyl-7-O-triethyl- silylbaccatin III
72
[0455] To a dry flask under an argon atmosphere containing
7-O-triethylsilyl-10-desacetyl baccatin III (2.093 g, 3.177 mmol)
was added dry THF (30 mL) and cooled to -70.degree. C. To this was
added 1.6M n-butyllithium (2.38 mL, 3.81 mmol) in a dropwise
fashion. After stirring for 15 min, benzyl chloroformate (0.91 mL,
6.35 mmol) was added dropwise. The resulting mixture was stirred
for 3 h with gradual warming to ambient temperature. The reaction
was quenched with 25 mL of sat. NH.sub.4Cl, washed with brine, and
dried with MgSO.sub.4. Flash chromatography (silica gel, 30-45%
ethyl acetate/hexane) furnished 2.24 g (89%) of the title compound
as a white foam.
[0456] .sup.1H NMR (300 MHz, CDCl.sub.3) .delta. 8.10 (d, J=8.0,
2H); 7.63-7.58 (m, 1H) 7.47 (t, J=8.0, 2H); 7.41-7.26 (m, 5H); 6.29
(s, 1H); 5.61 (d, J=7.0, 1H); 5.20 (q, J=12.2, 2H); 4.96 (d, J=9.0,
1H); 4.87-4.84 (m, 1H); 4.48 (dd, J=6.7, J=10.4, 1H); 4.30 (d,
J=8.5, 1H); 4.14 (d, J=8.5, 1H); 3.84 (d, J=7.0, 1H); 2.58-2.48 (m,
1H); 2.29 (m, 4H); 2.20 (s, 3H); 2.03 (d, J=5.0, 1H); 1.92- 1.83
(m, 1H); 1.68 (s, 3H); 1.17 (s, 3H); 1.04 (s, 3H); 0.91 (t, J=7.5,
9H); 0.57 (q, J=7.4, 6H).
[0457] (b) preparation of
10-desacetyl-10-O-benzyloxycarbonyl-3'-N-debenzo-
yl-3'-N-(t-butyloxycarbonyl)-2',7-bis-O-triethylsilylpaclitaxel
73
[0458] To a dry flask containing the product of step (a) (3.50 g,
4.42 mmol) was added a small amount of toluene and the solution was
then concentrated under vacuum. This flask was placed under an
argon atmosphere and 100 mL of dry THF was added. The flask was
cooled to -70.degree. C. and 1.0M lithium hexamethyldisilazide
(6.19 mL, 6.19 mmol) was added in a dropwise fashion. After
stirring for 20 min. a solution of
(3R,4S)-1-(t-butyloxycarbonyl)-4-phenyl-3-triethylsilyloxy-2-azetidinone
(2.58 g, 7.07 mmol) in 10 mL dry THF was added dropwise. The
reaction mixture was stirred for 3.5 h, gradually warming to
ambient temperature. It was then quenched with 70 mL of sat.
NH.sub.4Cl washed with brine and dried with MgSO.sub.4. Flash
chromatography (silica gel, 5-15% ethyl acetate/hexanes) provided
5.12 g (99%,) of the title compound as a white foam.
[0459] .sup.1H NMR (300 MHz, CDCL.sub.3) .delta. 8.11 (d, J=8.0,
2H); 7.60-7.58 (m, 1H); 7.48 (t, J=8.0, 2H); 7.24 -7.26 (m, 10H);
6.32-6.26 (m, 2H); 5.69 (d, J=7.0, 1H); 5.47 (bd, J=9.7, 1H);
5.31-5.10 (m, 3H); 4.94 (d, J=8.5, 1H); 4.56 (s, 1H); 4.46 (dd,
J=6.9, J=10.6, 1H); 4.31 (d, J=8.3, 1H); 4.17 (d, J=8.3, 1H); 3.81
(d, J=7.0, 1H); 2.53 (s, 3H); 2.48-2.33 (m, 1H); 2.22-2.17 (m, 1H);
2.09 (s, 3H); 1.95-1.86 (m, 1H); 1.70 (s, 3H); 1.65 (s, 1H); 1.52
(s, 1H); 1.30 (s, 9H); 1.26-1.19 (m, 6H); 0.94-0.87 (m. 9H);
0.80-0.75 (m, 9H); 0.61-0.53 (m, 6H); 0.48-0.30 (m, 6H).
[0460] (c) preparation of
10-desacetyl-3'-N-debenzoyl-3'-N-(t-butyloxycarb-
onyl)-7-O-triethylsilylpaclitaxel 74
[0461] The product of step (b) (5.12 g, 4.40 mmol) was dissolved
into 100 mL of ethyl acetate, transferred to a Parr bottle and
placed under a blanket of argon. To this was added 10% palladium on
carbon (2.4 g) and the reaction mixtre was placed on a Parr
hydrogenation apparatus (55 psi) for a period of 8 h. The reaction
mixture was filtered through a plug of Celite and concentrated.
Flash chromatography (silica gel, 15-20% ethyl acetate/hexane)
provided 3.24 g (79% ) of the title compound as a white foam.
Hydrolysis of the 2'-triethylsilyl group of the product of step (b)
was a result of trace acidic residues in the Parr equipment.
[0462] .sup.1H NMR (300 MHz, CDCl.sub.3) .delta. 8.10 (d,J=8.0,
2H); 7.63-7.58 (m, 1H); 7.49 (d, J=8.0, 2H); 7.39-7.26 (m. 5H);
6.27-6.17(m, 1H); 5.64 (d, J=7.2); 5.42(d, J=9.4, 1H); 5.28-5.25
(m, 1H); 5.12 (s, 1H); 4.92 (d, J=8.6, 1H); 4.62 (bs, 1H);
4.38-4.28 (m, 3H); 4.17 (d, J=8.5, 1H); 3.85 (d, J=6.7, 1H); 3.36
(d, J=5.3, 1H); 2.49-2.40 (m, 1H); 2.36 (s, 3H);
[0463] 2.25 (bd, J=8.7, 2H); 1.99-1.91 (m, 1H); 1.85 (s, 3H); 1.74
(s, 3H); 1.69 (s, 1H), 1.67 (s, 1H); 1.35 (s, 9H); 1.22 (s, 3H);
1.11 (s, 3H); 0.93 (t, J=7.5 9H); 0.61-0.49 (m. 6H).
[0464] (d) preparation of
10-desacetyl-2'-O-benzyloxycarbonyl-3-N-debenzoy-
l-3'-N-(t-butyloxycarbonyl)-7-O-triethylsilylpaclitaxel 75
[0465] To a flask containing the product of step (c) (3.24 g, 3.51
mmol) was added 30 mL of dry dichloromethane. The flask was placed
under argon and cooled to 0.degree. C. N,N-diisopropylethylamine
(1.22 mL, 7.02 mmol) was added to the reaction mixture, followed by
addition of benzyl chloroformate (1.00 mL, 7.02 mmol) in a dropwise
manner. After 15 min, the cooling bath was removed and the reaction
allowed to stir at ambient temperature for 7 h. The mixture was
quenched with 30 mL sat. NH.sub.4Cl, washed with brine and dried
with MgSO.sub.4. Flash chromatography (silica gel, 7-20% ethyl
acetate/hexane) provided 3.24 g (89%) of the title compound as a
white solid.
[0466] .sup.1H NMR (300 MHz, CDCl.sub.3) .delta. 8.10 (d, J=8.0,
2H); 7.62-7.57 (m, 1H); 7.48 (t, J=8.0, 2H); 7.40-7.26 (m, 10H);
6.33-6.27 (m, 1H); 5.66 (d, J=7.0, 1H); 5.49-5.42 (m, 2H); 5.31 (s,
1H); 5.22-5.13 (m , 3H); 4.93 (d, J-9.4, 1H); 4.38 (dd, J=6.5,
J=10.7, 1H); 4.34-4.28 (m, 2H); 4.18 (d J=8.3, 1H); 3.90 (d, J=6.7,
1H); 2.52-2.30 (m, 4H); 2.24-2.20 (m, 1H); 1.97-1.87 (m, 3H); 1.74
(s, 3H); 1.59 (s, 3H); 1.32 (s, 9H); 1.26, (s, 3H); 1.11 (s, 3H);
0.96-0.88 (m, 9H); 0.61-0.48 (m, 6H).
[0467] (e) preparation of
10-desacetyl-2'-O-benzyloxycarbonyl-3'-N-debenzo-
yl-3'-N-(t-butyloxycarbonyl)-10-O-(dibenzylphosphonooxymethyl)-7-O-triethy-
lsilylpaclitaxel 76
[0468] The product of step (d) was dissolved into 13.5 mL (54%) of
DMSO, 8.75 mL (35%) acetic anhydride and 2.75 mL (11%) glacial
acetic acid and placed under an atmosphere of argon. The reaction
mixture stirred for 56 h, after which it was diluted with ethyl
acetate to a volumn of 60 mL. The solution was washed with sat.
NaHCO.sub.3 until neutral by pH paper and then washed with brine.
The organic fraction was dried with MgSO.sub.4 and concentrated.
Flash chromatography with 15-20% EtOAc/hexane provided 3.12 g of
crude white foam with the desired thiomethyl acetal product (i.e.
10-desacetyl-2-O-benzyloxycarbonyl-3-N-de-
benzoyl-3-N-(t-butyloxycarbonyl)-10-O-(methylthiomethyl)-7-O-triethylsilyl-
paclitaxel accounting for 70% of the material by NMR.
[0469] The above crude mixture (3.12 g) was then dissolved in
1,2-dichloroethane (61 mL) and placed under a blanket of argon.
4.ANG. powdered molecular sieves (3.12 g) were added and the
resulting heterogeneous mixture was stirred vigorously. To this was
added a solution of recrystallized N-iodosuccinimide (0.830 g, 3.69
mmol) and dibenzyl phosphate (1.027 g, 3.69 mmol) in dry THF (46
mL) via cannula. The resulting mixture was stirred for 5 h,
filtered through a plug of Celite, and diluted to a volume of 250
mL with ethyl acetate. It was washed with (2.times.125 mL) of cold
2% NaHSO.sub.3, cold 6% NaHCO.sub.3 (2.times.125 mL) and brine. The
organic phase was dried with MgSO.sub.4 and concentrated. Flash
chromatography (silica gel, 25-35% ethyl acetate/hexane) provided
1.52 g (40%) of title compound as a white solid.
[0470] .sup.1H NMR (CDCl.sub.3, 300 MHz) .delta. 8.08 (d, J=7.0,
2H); 7.59-7.55 (m, 1H); 7.46 (t, J=7.2, 2H); 7.38-7.25 (m, 20H);
6.30 (t, J=8.5, 1H); 5.65 (d, J=6.8, 1H); 5.49-5.39 (m, 4H); 5.32
(s, 1H); 5.18-4.19 (m, 4H); 4.93 (d, J=9.2, 1H); 4.44 (dd, J=6.6,
J=10.2, 1H); 4.31 (d, J=8.4, 1H); 4.16 (d, J=8.5, 1H); 3.80 (d,
J=6.9, 1H); 2.69-2.39, (m, 4H), 2.33-2.23 (m, 3H); 2.03 (s, 3H);
1.90 (t, J=12.6, 1H); 1.68-1.63 (m, 6H); 1.28 (s, 9H); 1.16-1.10
(m, 6H); 0.93 (t, J=7.4, 9H); 0.55 (q, J=7.8, 6H).
[0471] .sup.13C NMR (CDCl.sub.3, 75.5 MHz) .delta. 204.1, 169.7,
167.9, 167.1, 151.1, 140.7, 135.7, 133.6, 130.2, 129.2, 128.9,
128.8, 128. 7, 128.6, 128.5, 128.4, 128.3, 128.2, 128.0, 127.8,
126.4, 90.4, 84.2, 81.1, 80.4, 79.3, 78.8, 74.9, 72.8, 72.0, 70.5,
69.2, 69.1, 69.0, 58.1, 46.8, 43.2, 37.1, 35.0, 28.1, 26.5, 22.8,
21.0, 14.1, 10.0, 6.9, 5.5.
[0472] M.S. (FAB) m/z+: 1345
[0473] (f) preparation of
10-desacetyl-2'-O-benzyloxycarbonyl-3'-N-debenzo-
yl-3'-N-(t-butyloxycarbonyl)-10-O-(dibenzylphosphonooxymethyl)paclitaxel
77
[0474] A solution of the product of step (e) (50.8 mg, 0.038 mmol)
in dry THF (2.5 mL), under argon was cooled to -40.degree. C. To
this solution was added tetrabutylammonium fluoride (0.057 mL,
0.057 mmol) in THF (1.0M) in a dropwise manner. The reaction
mixture stirred for 1.5 h with gradual warming to -20.degree. C.
The mixture was quenched with 15 mL sat. NH.sub.4Cl and diluted
with 30 mL EtOAc. The organic phase was washed with 2.times.15 mL
NaHCO.sub.3, and brine. It was dried with MgSO.sub.4 and
concentrated. Preparative layer chromatography (silica gel, 50%
ethyl acetate/hexane) provided 36 mg (77%) of title compound as a
white powder.
[0475] .sup.1H NMR (CDCl.sub.3, 300 MHz) .delta. 8.10 (d, J=8.5,
2H); 7.60-7.55 (m, 1H); 7.49-7.44 (m, 2H); 7.36-7.18 (m, 20H);
6.27-6.22 (m, 1H); 5.78 (s, 1H); 5.67 (d, J=7.0, 1H); 5.44-5.34 (m,
3H); 5.27 (d, J=2.2, 1H); 5.24-5.05 (m, 4H); 5.01-4.91 (m, 4H);
4.39-4.28 (m, 2H); 4.17 (d, J=8.2, 1H); 3.87 (d, J=7.0, 1H);
2.58-2.51 (m, 1H); 2.41 (s, 3H); 2.40-2.18 (m, 2H), 2.00-1.87 (m,
5H); 1.73-1.69 (m, 4H); 1.30 (s, 9H); 1.22-1.15 (m, 6H).
[0476] M.S. (FAB) m/z+: 1231
[0477] (g) preparation of
10-desacetyl-3'-N-desbenzoyl-3'-N-(t-butyloxycar-
bonyl)-10-O-(phosphonooxymethyl)paclitaxel triethanolamine salt
78
[0478] A 500 mL Parr bottle was charged with
10-desacetyl-2'-O-benzyloxyca-
rbonyl-3'-N-debenzoyl-3'-N-(t-butyloxycarbonyl)-10-O-(dibenzylphosphonooxy-
methyl)paclitaxel (264.9 mg, 0.215 mmol) and ethyl acetate (20 mL).
The flask was then flushed with argon and 10% Pd/C (318 mg) was
added. The resulting mixture was placed on a Parr apparatus with a
55 pounds per square inch (psi) hydrogen atmosphere. The reaction
was monitored by HPLC (70:30 CH.sub.3CN/Q8 buffer pH 6.0, 1.00
mL/min., Zorbax C-18 column, 25.0 cm, .lambda.=230 nm) until no
starting material was evident (12.5 hours). The mixture was
filtered through a plug of Celite, which was washed with ethyl
acetate and a small amount of dichloromethane. The resulting
filtrate was concentrated and the residue was taken up in
dichloromethane (5 mL). Addition of hexane caused a white
precipitate to form, of which 140.3 mg of the free acid (80% purity
by HPLC) was isolated as a white solid. This material was passed
directly on to the next step.
[0479] To a flask containing the above free acid (140 mg, 0.153
mmol) was added dichloromethane (10 mL). The resulting solution was
then treated with 0.100M triethanolamine solution in ethyl acetate
(1.16 mL, 0.116 mmol) which caused the solution to become turbid.
Approximately 2 mL of hexane was added and the mixture was placed
at -20.degree. C. overnight. The resulting precipitate was filtered
through a 4.0-5.5 .mu.m fritted glass funnel. The solid was removed
and placed under vacuum for 4 h to yield 69.9 mg (42%) the title
triethanolamine salt as a gray powder, which was determined to be
95-96% pure by HPLC analysis. (T.sub.R=2.05 min, 70:30
CH.sub.3CN/Q8 Buffer pH 6.0, 1.00 mL/min, Zorbax C-18 25.0 cm,
.lambda.=230 nm).
[0480] .sup.1H-NMR (d.sub.6-acetone/D.sub.2O, 300 MHz): .delta.
8.03 (d, J=7.4, 2H); 7.65 (t, J=7.3, 1H); 7.54 (t, J=7.6, 2H);
7.42-7.33 (m, 5H); 7.21 (t, J=7.0, 1H); 6.09 (t, J=9.0, 1H); 5.81
(s, 1H); 5.59 (d, J=7.0, 1H); 5.12 (bs, 2H); 4.93 (d, J=8.4, 2H),
4.56 (d, J=4.9, 1H); 4.31-4.26 (m, 1H); 4.11 (s, 2H); 3.41-3.37 (m,
6H); 2.42-2.32 (m, 5H); 2.15 (bs, 1H); 1.97 (s, 3H); 1.77-1.64 (m,
2H); 1.58 (s, 3H); 1.13 (s, 9H); 1.15-1.07 (m, 6H).
[0481] .sup.13C NMR (d-acetone, D.sub.2O, 75.6 MHz): .delta. 171.6,
166.9, 156.6, 141.8, 135.1, 134.2, 131.0, 130.7,129.4, 129.3,
128.4, 128.1, 88.3, 85.4, 81.9, 79.7, 78.6, 78.1, 76.8, 76.0, 74.8,
71.9, 71.2, 47.4, 44.0, 37.1, 36.3, 28.5, 27.0, 23.1, 22.0, 14.7,
10.4.
[0482] HRMS: MNa.sup.+, 940.3142 (Calculated for
C.sub.44H.sub.56NO.sub.18- PNa=940.3133)
Example 10. 2'-O-Phosphonooxymethoxymethylpaclitaxel
[0483] (a) preparation of
2'-O-(methylthiomethoxymethyl)-7-O-triethysilylp- aclitaxel 79
[0484] To a solution of 7-O-triethylsilylpaclitaxel (70.0 mg, 72.2
mmol), bis(methylthiomethyl)ether (90 mg, 72.2 mmol), molecular
seives (70 mg), and N-iodosuccinimide (160 mg, 72.2 mmol) in THF
(2.0 ml) at room temperature was added silver triflate (5.0 mg,
19.5 mmol) and the resulting solution was stirred for 2 h. The
reaction mixture was then diluted with ethyl acetate and filtered
through a pad of celite. The filtrate was washed with saturated
aqueous sodium bicarbonate solution, followed by a 1:1 (v:v)
mixture of saturated aqueous sodium bicarbonate and 5% aqueous
sodium thiosulfate solution and finally brine. The organics were
then dried over sodium sulfate and concentrated in vacuo. The
residual oil was purified via flash chromatography (3:1,
hexanes:ethyl acetate) to provide 22.0 mg (29%) of the title
compound as a white solid:
[0485] .sup.1H NMR (300 MHz, CDCl.sub.3) .delta. 8.12-7.20 (15H,
m), 7.04 (1H, d, J=8.9 Hz), 6.41 (1H, s), 6.25 (1H, m), 5.81 (1H,
dd, J=8.9, 2.4 Hz), 5.68 (1H, d, J=7.0 Hz), 4.93 (1H, d, 8.0 Hz),
4.79 (2H, m), 4.71 (1H, d, 2.4 Hz), 4.45 (1H, dd, J=10.5, 6.6 Hz),
4.30 (1H, d, J=8.3 Hz), 4.28 (1H, d, J=11.7 Hz), 4.17 (1H, d, J=8.3
Hz), 4.04 (1H, d, J=11.7 Hz), 3.80 (1H, d, J=6.9 Hz), 2.48-1.13
(25H, m, incl. singlets at 2.51, 2.13, 2.05, 2.01, 1.69, 1.19,
1.16), 0.98-0.85 (9H, m), 0.65-0.50 (6H, m).
[0486] (b) preparation of
2'-O-(dibenzylphosphonooxymethoxymethyl)-7-triet-
hylsilylpaclitaxel 80
[0487] To a solution of the product obtained in step (a) (15 mg,
0.0141 mmol) and molecular sieves (15 mg) in THF (0.5 ml) at room
temperature was added dibenzyl phosphate (20.0 mg, 0.089 mmol)
followed by N-iodosuccinimide (4.2 mg, 0.0187 mmol) and the
solution was stirred for 1 h. A TLC analysis of the reaction
mixture at this time indicated the presence of starting material
only. Silver triflate (5.0 mg, 0.019 mmol) was then added in three
portions over 2 h and the reaction was stirred for an additional 1
h. The reaction mixture was then diluted with ethyl acetate and the
resulting solution filtered through a pad of celite. The filtrate
was treated with a 1:1 (v:v) solution of saturated aqueous sodium
bicarbonate and 5% aqueous sodium thiosulfate solution. The organic
extract was then washed with brine, dried over sodium sulfate and
concentrated in vacuo. The residual oil was purified via flash
chromatography (1:1, hexanes:ethyl acetate) to provide 5.0 mg (33%)
of the title compound:
[0488] .sup.1H NMR (300 MHz, CDCl3) .delta. 8.08-7.16 (25H, m),
7.18 (1H, d, J=8.8 Hz), 6.41 (1H, s), 6.21(1H, m), 5.82 (1H, dd,
J=9.0, 3.1 Hz), 5.66 (1H, d, 7.0 Hz), 5.01-4.65 (10H, m), 4.56 (1H,
dd, J=14.7, 5.6 Hz), 4.43(1H, dd, J=10.4, 6.7 Hz), 4.29 (1H, d,
J=8.3 Hz), 4.16 (1H, d, J=8.3 Hz), 3.78 (1H, d, J=7.0 Hz),
2.60-1.13 (22H, m, incl. singlets at 2.49, 2.15, 1.93, 1.66, 1.15,
1.13, 3H each), 0.95-0.84 (9H, m), 0.63-0.45 (6H, m).
[0489] (c) preparation of 2'-O-phosphonooxymethoxymethylpaclitaxel
81
[0490] The product of step (b) is treated with tetrabutylammonium
fluoride according to the procedure given in Example 9(f) to remove
the 7-O-triethylsilyl protecting group. The compound thus obtained
is subject to catalytic hydrogenation according to the procedure
described in previous examples to provide the title compound.
Example 11. 2-O-Phosphonooxymethoxymethylpaclitaxel (Alternate
route)
[0491] (a) preparation of 2'-O-triethylsilylpaclitaxel 82
[0492] To a solution of paclitaxel (20.0 g, 0.0234 mol) and
imidazole (3.59 g, 0,052 mol) in 150 ML of DMF (dimethylformamide)
at 0.degree. C. was added triethylsilyl chloride (6.0 mL, 0.053
mol) in 2.0 mL quantities over 20 min. The reaction mixture was
then stirred at 0.degree. C. for 1 h. The mixture was then diluted
with ethyl acetate and saturated aqueous ammonium chloride. The
organic layer was removed, washed with brine, dried over sodium
sulfate and concentrated in vacuo to provide a yellow oil.
Purification of the crude product via flash chromatography
(hexanes: ethyl acetate: 1:3 then 1:1) provided 21.07 g (98% yield)
of the desired title compound as a colorless white solid.
[0493] .sup.1H-NMR (300 MHz, CDCl.sub.3) .delta. 8.15 (2H, m), 7.70
(2H, m), 7.65-7.30 (11H, m) 7.15 (1H, d, J=8.9 Hz), 6.30 (1H, s),
6.25 (1H, m), 6.70-6.10 (2H, m), 4.94 (1H, d, J=7.9 Hz), 4.67 (1H,
d, 2.0 Hz), 4.40 (1H, m), 4.29 (1H, d, J=8.4 Hz), 4.18 (1H, d,
J=8.4 Hz), 3.81 (1H, d, J=7.1 Hz), 2.65-1.10 (22H, including
singlets at 2.55, 2.20, 1.88, 1.69, 1.22, 1.13, 3H each).
[0494] (b) preparation of
2-O-triethylsilyl-7-O-benzyloxycarbonylpaclitaxe- l 83
[0495] Butyllithium (1.6M in hexanes, 12.9 mL, 8.06 mmol) was added
dropwise over 10 min to a solution of 2'-O-triethylsilylpaclitaxel
(22.3 g, 24.1 mmol) in THF (250 mL) cooled to -50.degree. C. The
resulting solution was stirred for 20 min and the temperature
maintained between -50.degree. C. and -35.degree. C. The reaction
mixture was then cooled to -50.degree. C. and benzyl chloroformate
(5.08 mL, 29.8 mmol) was added dropwise over 5 min. The reaction
mixture was maintained at -40.degree. C. for 30 min then
equilibrated to 0.degree. C. over approximately 30 min. The mixture
was then diluted with ethyl acetate and saturated aqueous ammonium
chloride and the resulting organic layer washed with brine, dried
over sodium sulfate and concentrated in vacuo. A .sup.1H-NMR
analysis of the crude reaction mixture showed the presence of
desired 2'-O-triethylsilyl-7-O-benzyloxycarbonylpaclitaxel as well
as 2'-O-triethylsilyl-7-epihydroxypaclitaxel (3:1 ratio,
respectively). This product mixture was used in the next step
without further purification and the isomers subsequently
separated. An analytical sample of the major product
2'-O-triethylsilyl-7-O-benzyloxycarbonylpaclitaxel was purified via
flash chromatography; .sup.1H-NMR (300 MHz, CDCl.sub.3) .delta.
8.12 (2H, m), 7.72 (1H, m), 7.65-7.27 (1H, d, J=8.8 Hz), 6.41 (1H,
m), 6.20 (1H, m), 5.72-5.65 (2H, m), 5.52 (1H, m), 5.24 (1H, d,
J=12.3 Hz), 5.16 (1H, d, J=12.3 Hz), 4.95 (1H, d, J=8.7 Hz), 4.69
(1H, s), 4.35 (1H, d, J=8.3 Hz), 4.25 (1H, d, J=8.3 Hz), 3.94 (1H,
d, J=6.8 Hz), 2.70-1.12 (22H, including singlets at 2.54, 2.14,
2.01, 1.80, 1.20, 1.15, 3H each), 0.81-0.73 (9H, m), 0.55-0.31 (6H,
m).
[0496] (c) preparation of 7-O-benzyloxycarbonylpaclitaxel 84
[0497] Hydrochloric acid (6N, 1.0 mL, 6.0 mmol) was added to a
solution the product from Step (b) (24.0 g, 22.6 mmol) in
acetonitrile (250 mL) cooled to 0.degree. C. After 10 min a TLC
analysis (hexanes : ethyl acetate, 1:1) indicated the reaction was
complete. The reaction mixture was diluted with saturated aqueous
sodium bicarbonate followed by ethyl acetate and the organic layer
was removed, washed with brine, dried using sodium sulfate and
concentrated in vacuo. The residual oil was purified using flash
chromatography (hexanes:ethyl acetate, 1:3, then 1:1) to provide
11.4 g (48% over 2 steps) of the title compound and 4.8 g (20%) of
7-epihydroxypaclitaxel.
[0498] .sup.1H-NMR (300 MHz, CDCl.sub.3) .delta. 8.09 (2H, m), 7.71
(2H, m), 7.65-7.27 (16H, m), 7.10 (1H, d, 8.9 Hz), 6.39 (1H, s),
6.16 (1H, m), 5.81 (1H, d, J=8.9, 2.4 Hz), 5.65 (1 H, d, J=6.9 Hz),
5.49 (1H, dd, J=10.6, 7.2 Hz), 5.20 (1H, d, J=11.9 Hz), 5.12 (1H,
d, J=11.9), 4.91 (1H, d, J=8.4 Hz), 4.78 (1H, m), 4.30 (1H, d,
J=8.4 Hz), 4.15 (1H, d, J=8.4 Hz), 3.91 (1H, d, J=6.8 Hz), 3.69
(1H, d, J=4.9 Hz), 2.65-1.10 (22H, including singlets at 2.39,
2.18, 1.81, 1.75, 1.21, 1.15, 3H each).
[0499] (d) preparation of
2'-O-(methylthiomethoxymethyl)-7-O-benzyloxycarb- onylpaclitaxel
85
[0500] Silver triflate (300 mg, 1.17 mmol) was added to a solution
7-O-benzyloxycarbonylpaclitaxel (5.53 g, 5.71 mmol), 1,
1'-dithiomethyldimethyl ether (7.8 g, 57.1 mmol), N-iodosuccinimide
(6.35 g, 28.3 mmol) and oven dried, powdered molecular sieves (5.0
g) in THF (110 mL) at room temperature. A TLC analysis
(hexanes:ethyl acetate, 1:1) of the reaction mixture after 20 min
indicated the conversion of approxiately 40% of the starting
material to a higher running product. Silver triflate (150 mg,
0.585 mmol) was then added and the reaction was monitored by TLC
which indicated after 30 min the reaction was appoximately 65%
complete. The mixture was diluted with ethyl acetate (100 mL),
filtered using a pad of celite and the filtrate was poured into a
separatory funnel containing 200 mL of a saturated aqueous solution
of sodium bicarbonate and 50 mL of a 5% aqueous sodium thiosulfate
solution. The organic layer was removed, washed with brine, dried
over sodium sulfate and concentrated in vacuo. The residual oil was
purified via flash chromatography (hexanes:ethyl acetate, gradient
elution 4:1 to 3:2) to provide 3.0 g (54% yield) of the title
product as a light yellow solid.
[0501] .sup.1H-NMR (300 MHz, CDCL3) .delta. 8.10 (2H, m), 7.74 (2H,
m), 7.66-7.25 (18H, m), 7.05 (1H, d, J=8.9 Hz), 6.40 (1H, s), 6.26
(1H, m), 5.77 (1H, dd, J=8.8, 2.5 Hz), 5.71 (1H, d, J=6.9 Hz), 5.51
(1H, dd, J=10.6, 7.1 Hz), 5.21 (1H, d, J=11.9 Hz), 5.14 (1 H, d,
J=11.9 Hz), 4.92 (1H, m), 4.79 (2H, m), 4.68 (1H, d, J=2.5 Hz),
4.31 (1H, d, J=11.8 Hz), 4.30 (1H, d, J=8.5 Hz), 4.16 (1H, d, J=8.5
Hz), 4.10 (1H, d, J=11.8 Hz), 3.93 (1H, d, J=6.9 Hz), 2.65-1.10
(25H including singlets at 2.50, 2.15, 2.05, 1.74, 1.72, 1.20,
1.15, 3H each).
[0502] (e) preparation of
2'-O-(dibenzylphosphonooxymethoxymethyl)-7-O-ben-
zyloxycarbonylpaclitaxel 86
[0503] To a solution of
2'-O-(methylthiomethoxymethyl)-7-O-benzyloxycarbon- ylpaclitaxel
(1.06 g, 1.07 mmol) and oven dried, powdered molecular sieves (1.0
g) in THF (20 mL) at room temperature was added dibenzyl phosphate
(1.49 g, 5.30 mmol) followed immediately by N-iodosuccinimide (2.65
g, 1.18 mmol). A TLC analysis (hexanes:ethyl acetate 1:1) of the
reaction mixture after 2.5 h indicated the reaction was
approximately 60% complete. N-iodosuccinimide (175 mg, 0.78 mmol)
was then added and the reaction stirred for an additional 30 min,
after which time a TLC analysis indicated the reaction was
complete. The reaction mixture was then diluted with ethyl acetate
(50 mL) and filtered using a pad of celite. The filtrate was poured
into a separatory funnel containing 100 mL of a saturated aqueous
solution of sodium bicarbonate and 20 mL of a 5% aqueous solution
of sodium thiosulfate. The organic layer was removed, washed with
brine, dried over sodium sulfate and concentrated in vacuo. The
residual oil was purified using flash chromatography (hexanes:ethyl
acetate, gradient elution, 3:1 to 1:1) to provide 750 mg (62%
yield) of the desired title compound as a white solid.
[0504] .sup.1H-NMR (360 MHz, CDCl.sub.3) .delta. 8.10 (2H, m), 7.79
(2H, m), 7.65-7.24 (26H, m), 7.10 (1H,m), 6.41 (1H, s), 6.20
(1H,m), 5.79 (1H, dd, J=8.8, 3.6 Hz), 5.65 (1H, d, J=7.0 Hz), 5.52
(1H,m), 5.20 (1H, d, J=11.8 Hz), 5.11 (1H, d, J=11.8 Hz), 5.04-4.85
(6H, m), 4.75-4.60 (4H, m), 4.30 (1H, d, 8.4 Hz), 4.15 (1H, d,J=8.4
Hz), 3.92 (1H, d, J=7.0 Hz) 2.65-1.10 (22 H including singlets at
2.48, 2.19, 1.95, 1.80, 1.20, 1.10, 3H each).
[0505] (f) preparation of 2'-O-phosphonooxymethoxymethylpaclitaxel
triethanolamine salt
[0506] Palladium (10%) on carbon was added to a solution of
2'-O-(dibenzylphosphonooxymethoxymethyl)-7-O-benzyloxycarbonylpaclitaxel
(500 mg, 0.382 mmol) in ethly acetate (40 mL) housed in a Parr
bottle. The vessel was affixed to a Parr apparatus and the reaction
mixture subjected to hydrogen at 50 psi. The reaction mixture was
shaken for 6.5 h, then filtered using a sintered glass funnel.
Triethanolamine (0.1N in ethyl acetate, 4.0 mL) was added to this
filtrate and the resulting solution was concentrated in vacuo. The
crude solid was suspended in approximately 5.0 mL of ethyl acetate
and the solvent decanted. This process was repeated three times and
the resulting title triethanolamine salt (300 mg) was obtained with
purity of 87% as determined by HPLC analysis. Further purification
of this compound via C18 chromatography (water:acetonitrile, 3:1)
provided the desired title compound (120 mg, 34%) at 95% purity by
HPLC.
[0507] .sup.1H-NMR (300 MHz, CD.sub.3COCD.sub.3, D.sub.2O) .delta.
9.05 (1H, d, J=8.7 Hz), 8.15-7.12 (21H, m), 6.40 (1H,m), 6.05 (1H,
m), 5.69-5.55 (2H, m), 5.01-4.85 (6H, m), 4.35 (1H, m), 4.14 (2H,
m), 3.96-3.85 (6H, m), 3.25 (1H, d, J=7.1 Hz), 3.30-3.15 (6H, m)
2.50-1.04 (22H, including singlets at 2.49, 2.15, 2.05, 1.81, 1.60,
3H each).
Example 12.
3'-N-debenzoyl-3'-N-(isopropyloxycarbonyl)-7-O-methylthiomethy-
lpaclitaxel
[0508] 87
[0509] To a solution of 7-O-methylthiomethylbaccatin III (408 mg,
0.630 mmol) in 10 mL of THF at -60.degree. C. was added nBuLi (0.30
mL, 2.5M, 0.75 mmol) and stirred for 10 min. (3R,
4S)-3-Triethylsilyloxy-4-phenyl-N-
-isopropyloxycarbonylazetidin-2-one (320 mg, 0.88 mmol) in 6 mL of
THF was added dropwise and then the reaction brought to 0.degree.
C. for 30 min. The solution was quenched with saturated NH.sub.4Cl
and extracted with ethyl acetate, shaken with Bu.sub.4NF (1.0 mL,
1.0M, 1.0 mmol) and then washed with brine, dried over MgSO.sub.4
and concentrated. The residue was chromatographed over silica gel
(1.5:1 hexane/ethyl acetate) to give 545 mg of a product which was
crystalized from acetone/hexane to give 476 mg of the title product
as a white solid (84%); IR(KBr) 3460, 1720, 1266, 12,44, 1230
cm.sup.-1; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta. 8.07 (d, J=7.2
Hz, 2H), 7.59 (t, J=7.2 Hz, 1H), 7.47 (t, J=7.5 Hz, 2H), 7.32 (m,
5H), 6.51 (s, 1H), 6.18 (t, J=8.7 Hz, 1H), 5.65 (d, J=6.6 Hz, 1H),
5.50 (d, J=9.3 Hz, 1H), 5.28 (d J=8.4 Hz, 1H), 4.91 (d, J=8.1 Hz,
1H), 4.77 (m, 1H), 4.64 (bs, 3H), 4.26 (m, 2H), 4.15 (d, J=8.4 Hz,
1H), 3.83 (d, J=6.9 Hz, 1H), 3.44 (d, J=5.1 Hz, 1H), 2.78 (m, 1H),
2.34 (s, 3H), 2.25 (d, J=9.0 Hz, 2H), 2.17 (s, 3H), 2.14 (s, 1H),
2.10 (s, 3H), 1.96 (s, 3H), 1.83 (m, 1H), 1.73 (s, 3H), 1.15 (m,
12H); .sup.13C NMR (CDCl.sub.3, 75.5 Hz) .delta. 201.8, 170.4,
169.2, 167.0, 156.3, 140.1, 138.3, 133.7, 133.3, 130.2, 129.1,
128.8, 128.6, 128.1, 126.8, 83.8, 81.4, 78.7, 76.0, 75.5, 74.5,
74.0, 73.6, 72.2, 68.9, 57.5, 56.4, 47.1, 43.2, 35.3, 32.9, 26.6,
22.6, 22.0, 21.9, 20.9, 15.1, 14.6, 10.9
[0510] FABMS (NOBA) M+Na calcd for C.sub.46H.sub.57NSO.sub.15: 918.
Found: 918.
[0511] Anal. calcd for C.sub.46H.sub.57NSO.sub.15: C, 61.66; H,
6.41; N, 1.56. Found: C, 61.63; H, 6.36; N, 1.68.
Example 13.
3'-N-Debenzoyl-3'-N-(n-butyloxycarbonyl)-7-O-methylthiomethylp-
aclitaxel
[0512] 88
[0513] To a solution of 7-O-methylthiomethylbaccatin III (425 mg,
0.66 mmol) in 10 mL of THF at -60.degree. C. was added nBuLi (0.30
mL, 2.5M, 0.75 mmol) and stirred for 10 min.
(3R,4S)-3-Triethylsilyloxy-4-phenyl-N--
(n-butyloxycarbonyl)azetidin-2-one (350 mg, 0.93 mmol) in 6 mL of
THF was added dropwise and then the reaction brought to 0.degree.
C. for 30 min. The solution was quenched with saturated NH.sub.4Cl
and extracted with ethyl acetate, shaken with Bu.sub.4NF (1.0 mL,
1.0M, 1.0 mmol) and then washed with brine, dried over MgSO.sub.4
and concentrated. The residue was chromatographed over silica gel
(1.5:1 hexane/ethyl acetate) to give 581 mg of the title product
which was crystalized from toluene/hexane to give 464 mg of a white
solid (77%); IR(KBr) 3444, 1722, 1372, 1242, 1108, 1066, 1026, 988
cm.sup.-1; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta. 8.08 (d, J=7.2
Hz, 2H), 7.59 (t, J=7.5 Hz, 1H), 7.47 (t, J=7.2 Hz, 2H), 7.39 -
7.11 (m, 5H), 6.51 (s, 1H), 6.20 (t, J=8.7 Hz, 1H), 5.65 (d, J=6.9
Hz, 1H), 5.56 (d, J=9.3 Hz, 1H), 5.29 (d J=8.4 Hz, 1H), 4.91 (d,
J=8.1 Hz, 1H), 4.65 (bs, 3H), 4.27 (m, 2H), 4.15 (d, J=8.4 Hz, 1H),
3.97 (m, 2H), 3.84 (d, J=6.9 Hz, 1H), 3.45 (d, J=4.8 Hz, 1H), 2.78
(m, 1H), 2.33 (s, 6H), 2.25 (d, J=8.7 Hz, 2H), 2.17 (s, 3H), 2.10
(s, 3H), 1.96 (s, 3H), 1.83 (m, 1H), 1.74 (s, 3H), 1.62 (s, 1H),
1.48 (m, 2H), 1.19 (m, 5H), 0.83 (t, J=7.2 Hz, 3H); .sup.13C NMR
(CDCl.sub.3, 75.5 Hz) .delta. 201.9, 172.3, 170.5, 169.2, 167.0,
156.3, 140.1, 138.4, 133.8, 133.4, 130.2, 129.2, 129.0, 128.9,
128.7, 128.2, 126.8, 125.3, 83.9, 81.4, 78.8, 77.3, 76.0, 75.6,
74.6, 74.1, 73.7, 72.2, 65.4, 57.5, 56.5, 47.2, 43.2, 35.4, 26.6,
22.6, 21.5, 21.0, 18.9, 15.1, 14.7, 13.7, 10.9.
[0514] FABMS (NOBA) M+H calcd for C.sub.47H.sub.60NSO.sub.15: 910.
Found: 910.
[0515] Anal. calcd for C.sub.47H.sub.59NSO.sub.15: C, 62.03; H,
6.53; N, 1.54. Found: C, 62.16; H, 6.45; N, 1.57.
Example 14.
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)-7-O-methylthiomethylpac-
litaxel
[0516] (a) preparation of
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)-2-O-triet-
hylsilyl-7-O-methylthiomethylpaclitaxel 89
[0517] To a solution of HMDS (0.275 mL, 1.30 mmol) in 8 mL of THF
was added a solution of n-BuLi (0.48 mL, 2.5M in hexanes, 1.20
mmol) and stirred 5 minutes at -55.degree. C. To this solution was
added 7-O-methylthiomethylbaccatin III (639 mg, 0.99 mmol) in 8 mL
of THF and stirred for 10 minutes before addition of an 8 mL
solution of
(3R,4S)-3-triethylsilyloxy-4-phenyl-N-(t-butoxycarbonyl)azetidin-2-one
(575 mg, 1.52 mmol). The cold bath was removed and replaced with a
0.degree. C. bath and the reaction stirred for 30 minutes. The
solution was diluted with ethyl acetate and washed with saturated
NH.sub.4Cl solution, dried over MgSO.sub.4 and concentrated. The
residue was chromatographed over silica gel (3:1 hexane/ethyl
acetate) to give 1.0 g of the title product (98%); .sup.1H-NMR
(CDCl.sub.3, 300 MHz) .delta. 8.09 (d, J=6.9 Hz, 2H), 7.57 (m, 1H),
7.46 (t, J=7.8 Hz, 2H), 7.35 (m, 2H), 7.26 (m, 3H), 6.55 (S, 1H),
6.25 (t, J=9.6 Hz, 1H), 5.68 (d, J=6.9 Hz, 1H), 5.45 (bd, J=9.3 Hz,
1H), 5.27 (bd, 1H), 4.95 (d, J=7.8 Hz, 1H), 4.65 (S, 2H), 4.53 (S,
1H), 4.29 (m, 2H), 4.17 (d, J=8.4 Hz, 1H), 3.89 (d, J=6.9 Hz, 1H),
2.81 (m, 1H), 2.51 (S, 3H), 2.37 (dd, J=15.3, 9.6 Hz, 1H), 2.17 (s,
3H), 2.10 (s, 3H), 2.03 (s, 3H), 1.85 (m, 1H), 1.74 (s, 3H), 1.63
(d, J=14.1 Hz, 1H), 1.29 (s, 9H), 1.21 (s, 6H), 0.76 (t, J=7.8 Hz,
9H), 0.36 (m, 6H); .sup.13C-NMR (CDCl.sub.3, 75.5 Hz) .delta.
202.0, 171.6, 170.1, 169.3, 167.1, 155.2, 141.0, 139.0, 133.6,
132.8, 130.2, 129.2, 128.7, 128.5, 127.7, 126.4, 83.9, 81.2, 79.9,
78.9, 76.0, 75.7, 75.2, 74.8, 74.2, 71.3, 57.3, 56.7, 47.0, 43.3,
35.3, 33.0, 28.2, 26.4, 23.0, 21.5, 21.0, 15.0, 14.4, 10.9, 6.5,
4.3; IR(film) 3448 (s), 1720, 1242, 1120, 1056 cm.sup.-1.
[0518] FABMS (NOBA) M+H calcd for C.sub.53H.sub.74NSSiO.sub.15:
1024.4549. Found: 1024.4583.
[0519] (b) preparation of
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)-7-O-methy-
lthiomethylpaclitaxel 90
[0520] To a solution of the
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)-2-O-tri-
ethylsilyl-7-O-methylthiomethylpaclitaxel (269 mg, 0.26 mmol) in 6
mL of THF was added tetrabutylammonium fluoride (0.3 mL, 1.0M in
THF, 0.3 mmol) and stirred 10 minutes. The solution was diluted
with ethyl acetate and washed with brine, dried over MgSO.sub.4 and
concentrated and the residue was chromatographed over silica gel
(1:1 hexane/ethyl acetate) to give 240 mg of the title product
(95%); IR(film) 3440, 1720, 1370, 1242, 1170, 1108, 1066, 756
cm.sup.-1; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta. 8.06 (d, J=7.2
Hz, 2H), 7.57 (t, J=7.2 Hz, 1H), 7.46 (t, J=7.8 Hz, 2H), 7.35 (m,
5H), 6.52 (s, 1H), 6.16 (t, J=8.7 Hz, 1H), 5.64 (d, J=6.9 Hz, 1H),
5.43 (bd, J=9.3 Hz, 1H), 5.24 (bd, J=8.1 Hz, 1H), 4.91 (d, J=8.1
Hz, 1H), 4.63 (m, 3H), 4.26 (m, 2H), 4.14 (d, J=8.4 Hz, 1H), 3.83
(d, J=6.9 Hz, 1H), 3.46 (d, J=5.4 Hz, 1H), 2.77 (m, 1H), 2.34 (s,
3H), 2.27 (d, J=8.7 Hz, 2H), 2.16 (s, 3H), 2.09 (s, 3H), 1.97 (s,
3H), 1.79 (m, 2H), 1.72 (s, 3H), 1.32 (s, 9H), 1.19 (s, 3H), 1.18
(s, 3H); .sup.13C-NMR (CDCl.sub.3, 75.5 Hz) .delta. 202.0, 172.7,
170.3, 169.2, 167.0, 155.3, 140.3, 138.4, 133.7, 133.2, 130.2,
129.1, 128.8, 128.7, 128.0, 126.7, 83.9, 81.3, 80.2, 78.6, 76.5,
76.1, 75.4, 74.6, 74.0, 73.6, 72.3, 57.4, 56.1, 47.1, 43.2, 35.3,
32.8, 28.2, 26.5, 22.6, 21.0, 15.1, 14.6, 10.9.
[0521] FABMS (NOBA) M+H calcd for C.sub.47H.sub.60NO.sub.15S:
910.3684. Found: 910.3706.
Example 15.
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)-2'-O-ethyloxycarbonyl-7-
-O-methylthiomethylpaclitaxel
[0522] 91
[0523] To a solution of
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)-7-O-methylt-
hiomethylpaclitaxel (428 mg, 0.47 mmol) in 10 mL of dichloromethane
was added diisopropylethyl amine (0.85 mL, 4.8 mmol) and DMAP (20
mg) and cooled to 0.degree. C. The ethyl chloroformate (0.25 mL,
2.6 mmol) was then added and stirred for 1 hr. The solution was
diluted with ethyl acetate and washed with bicarbonate and brine,
dried (MgSO.sub.4) and concentrated. The residue so obtained was
chromatographed over silica gel (1:1 hexane/ethyl acetate) to give
428 mg of the title ethyl carbonate (92%); IR(film) 3448 (w), 1750,
1720, 1370, 1244, 1064 cm.sup.-1; .sup.1H-NMR (CDCl.sub.3, 300 MHz)
.delta. 8.09 (d, J=7.2 Hz, 2H), 7.59 (t, J=7.2 Hz, 1H), 7.48 (t,
J=7.8 Hz, 2H), 7.39 (m, 2H), 7.31 (m, 3H), 6.55 (s, 1H), 6.25 (t,
J=9.0 Hz, 1H), 5.68 (d, J=7.2 Hz, 1H), 5.40 (bm, 2H), 5.25 (s, 1H),
4.95 (d, J=8.1 Hz, 1H), 4.65 (s, 2H), 4.29 (m, 2H), 4.15 (m, 3H),
3.88 (d, J=6.9 Hz, 1H), 2.81 (m, 1H), 2.43 (s, 3H), 2.32 (m, 1H),
2.21 (m, 1H), 2.16 (s, 3H), 2.11 (s, 3H), 2.08 (s, 3H), 1.84 (m,
1H), 1.74 (s, 3H), 1.62 (s, 1H), 1.32 (s, 9H), 1.28 (t, J=7.2 Hz,
3H), 1.20 (s, 6H); .sup.13C-NMR (CDCl.sub.3, 75.5 Hz) .delta.
202.0, 169.7, 169.1, 168.1, 167.0, 155.1, 154.1, 141.0, 137.2,
133.6, 132.9. 130.2., 129.2, 128.9, 128.7, 128.2, 126.4, 83.9,
81.2, 80.4, 78.9, 76.5, 76.0, 75.8, 74.8, 74.2, 72.0, 65.1, 57.4,
47.1, 43.3, 35.1, 33.0, 28.1, 26.4, 22.7, 21.3, 20.9. 15.0, 14.5,
14.1, 10.9.
[0524] FABMS (NOBA) M+H calcd for C.sub.50H.sub.64NSO.sub.17:
982.3895. Found: 982.3874.
Example 16.
3'-N-Debenzoyl-3'-N-(t-butoxycarbonyl)-7-O-methylthiomethyl-10-
-deacetyl-10-hydroxymethylcarbonyl(paclitaxel)
[0525] (a) preparation of
7-O-Triethylsilyl-10-deacetyl-10-benzyloxymethyl- carbonyl baccatin
III 92
[0526] To a solution of 7-O-triethylsilyl-10-deacetylbaccatin III
(3.85 g, 5.85 mmol) in 40 mL of THF at -60.degree. C. was added
n-BuLi (2.6 mL, 2.5M in hexanes, 6.5 mmol) and stirred for 5 min
before addition of benzyloxyacetyl chloride (1.0 mL, 6.5 mmol).
After stirring for 30 min at -60.degree. C. and then warming to
ambient temperature the solution was diluted with ethyl acetate and
washed with bicarbonate. The solution was dried over MgSO.sub.4 and
concentrated and the residue chromatographed over silica gel (2:1
then 1:1 hexane/ethyl acetate) to give 4.36 g of product (92%);
IR(film) 3478 (br), 1724, 1270, 1244, 1136, 1110, 1070 cm.sup.-1;
.sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta. 8.08 (d, J=7.2 Hz, 2H),
7.60-7.23 (m, 8H), 6.54 (s, 1H), 5.60 (d, J=6.9 Hz, 1H), 4.94 (d,
J=7.8 Hz, 1H), 4.79 (bq, 1H), 4.69 (s, 2H), 4.49 (dd, J=10.5, 6.6
Hz, 1H), 4.26 (m, 2H), 4.12 (m, 1H), 3.85 (d, J=6.9 Hz, 1H), 2.52
(m, 1H), 2.26 (s, 3H), 2.23 (m, 2H), 2.18 (s, 3H), 2.10 (m, 1H),
1.86 (m, 1H), 1.66 (s, 3H), 1.14 (s, 3H), 0.99 (s, 3H), 0.91 (t,
J=7.5 Hz, 9H), 0.56 (m, 6H).
[0527] Anal. Calcd. for C.sub.44H.sub.58SiO.sub.12: C, 65.49; H,
7.24. Found: C, 65.33; H, 7.27.
[0528] FABMS (NOBA) M+H calcd for C.sub.44H.sub.59SiO.sub.12 807.
Found: 807.
[0529] (b)
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)-10-deacetyl-10-benzyloxy-
methylcarbonyl(paclitaxel) 93
[0530] To a solution of
7-O-triethylsilyl-10-deacetyl-10-benzyloxymethylca- rbonyl baccatin
III (1.21 g, 1.66 mmol) in 50 mL of THF at -60.degree. C. was added
n-BuLi (0.7 mL, 2.5M in hexanes, 1.75 mmol) and stirred for 5 min
before addition of
(3R,4S)-3-triethylsilyloxy-4-phenyl-N-(t-butoxycar-
bonyl)azetidin-2-one (1.2 g, 3.2 mmol). After stirring for 5 min at
-60.degree. C. and then 30 min at 0.degree. C. the solution was
diluted with ethyl acetate and washed with saturated NH.sub.4Cl.
The solution was dried over MgSO.sub.4 and concentrated and the
residue chromatographed over silica gel (3:1 then 1:1 hexane/ethyl
acetate) to give 980 mg of product (53%). This product was
dissolved in 6 mL of acetonitrile and cooled to 0.degree. C. and
stirred with 0.60 mL of 6N HCl for 19 hrs. The solution was diluted
with ethyl acetate and washed with saturated bicarbonate, dried
over MgSO.sub.4 and chromatographed over silica gel (1:1
hexane/ethyl acetate) to give 570 mg of product (35%); IR(film)
3448 (br), 1716, 1496, 1368, 1316, 1270, 1246, 1176, 1108, 1070,
1026 cm.sup.-1; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta. 8.08 (d,
J=7.5 Hz, 2H), 7.59 (t, J=7.8 Hz, 1H), 7.47 (t, J=7.8 Hz, 2H), 7.36
(m, 1OH), 6.38 (s, 1H), 6.20 (t, J=9.0 Hz, 1H), 5.65 (d, J=6.9 Hz,
1H), 5.39 (bd, J=9.3 Hz, 1H), 4.93 (d, J=7.8 Hz, 1H), 4.69 (s, 2H),
4.60 (bs, 1H), 4.39 (m, 1H), 4.28 (m, 3H), 4.15 (d, J=8.4 Hz, 1H),
3.78 (d, J=6.9 Hz, 1H), 3.40 (bs, 1H), 2.54 (m, 1H), 2.43 (m, 1H),
2.36 (s, 3H), 2.28 (m, 2H), 1.84 (s, 4H), 1.72 (m, 1H), 1.67 (s,
3H), 1.31 (s, 9H), 1.23 (m, 1H), 1.21 (s, 3H), 1.10 (s, 3H).
[0531] Anal. Calcd. for C.sub.52H.sub.61NO.sub.16: C, 65.33; H,
6.43; N, 1.46. Found: C, 64.97; H, 6.44; N, 1.43.
[0532] FABMS (NOBA) M+Na calcd for C.sub.52H.sub.61NO.sub.16NA 978.
Found: 978.
[0533] (c) preparation of
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)-2-O-benzy-
loxycarbonyl-7-O-methylthiomethyl-10-deacetyl-10-benzyloxymethylcarbonyl(p-
aclitaxel) 94
[0534] To a solution of
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)-10-deacetyl-
-10-benzyloxymethylcarbonyl(paclitaxel) (570 mg, 0.59 mmol) in 10
mL of CH.sub.2Cl.sub.2 at 0.degree. C. was added diisopropylethyl
amine (0.15 mL, 0.86 mmol) and CbzCl (0.10 mL, 0.70 mmol). The
solution was stirred for 1 hr slowly warming to ambient
temperature. The solution was washed with bicarbonate and dried
over MgSO.sub.4 and concentrated. The residue in 10 mL of
acetonitrile at 0.degree. C. was stirred with benzoyl peroxide (780
mg, 3.22 mmol) and dimethylsulfide (0.50 mL, 6.8 mmol) slowly
warming to ambient temperature over 75 min. The solution was
diluted with ethyl acetate and washed with saturated bicarbonate,
dried over MgSO.sub.4 and chromatographed over silica gel (2:1
hexane/ethyl acetate) to give 412 mg of the title product (65%);
IR(film) 3438, 1754, 1722, 1368, 1272, 1244, 1176, 1110, 1066, 1028
cm.sup.-1; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta. 8.11 (d, J=7.2
Hz, 2H), 7.61 (t, J=7.2 Hz, 1H), 7.49 (t, J=7.8 Hz, 2H), 7.35 (m,
15H), 6.67 (s, 1H), 6.26 (t, J=8.7 Hz, 1H), 5.69 (d, J=6.6 Hz, 1H),
5.41 (bm, 2H), 5.29 (s, 1H), 5.14 (ABq, J=12, 5.7 Hz, 2H), 4.98 (d,
J=8 Hz, 1H), 4.72 (m, 4H), 4.32 (m, 3H), 4.19 (m, 2H), 3.90 (d,
J=6.0 Hz, 1H), 2.85 (m, 1H), 2.45 (m, 1H), 2.44 (s, 3H), 2.34 (m,
1H), 2.24 (m, 1H), 2.15 (s, 3H), 2.12 (s, 3H), 1.87 (m, 1H), 1.77
(s, 3H), 1.33 (s, 9H), 1.19 (s, 6H); .sup.13C NMR (CDCl.sub.3, 75.5
MHz) .delta. 201.6, 169.7, 168.7, 168.0, 167.0, 155.1, 154.1,
141.6, 137.1, 134.4, 133.7, 132.5, 130.2, 129.2, 128.9, 128.8,
128.7, 128.5, 128.4, 128.2, 128.0, 128.0, 126.4, 83.9, 81.2, 80.4,
78.8, 77.2, 76.2, 75.8, 74.7, 74.3, 73.4, 72.0, 70.6, 67.1, 57.4,
54.1, 47.1, 43.2, 35.2, 32.9, 28.1, 26.4, 22.7, 21.3, 15.2, 14.6,
10.9.
[0535] FABMS (NOBA) M+Na calcd for C.sub.62H.sub.71NO.sub.18SNa
1172. Found: 1172.
[0536] (d) preparation of
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)-7-O-methy-
lthiomethyl-10-deacetyl-10-hydroxymethylcarbonyl(paclitaxel) 95
[0537] To a solution of
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)-2-O-benzylo-
xymethylcarbonyl-7-O-methylthiomethyl-10-deacetyl-10-benzyloxycarbonyl(pac-
litaxel) (377 mg, 0.35 mmol) in 30 mL of ethanol was added a total
of 450 mg of 10% palladium on carbon catalyst and stirred under an
atmosphere of hydrogen for 120 hrs. The catalyst was removed by
filtration through celite and the solution concentrated. The
residue was chromatographed over silica gel (20% CH.sub.3CN / 79%
CH.sub.2Cl.sub.2 / 1% MeOH) to give 190 mg of the title product
(65%); IR(film) 3444 (br), 1724, 1368, 1246, 1174, 1096, 1070,
1026, 988 cm.sup.-1; .sup.1H NMR (CDCl.sub.3, 300 MHz) .delta. 8.07
(d, J=7.2 Hz, 2H) , 7.59 (t, J=7.2 Hz, 1H), 7.47 (t, J=7.8 Hz, 2H),
7.35 (m, 5H), 6.65 (s, 1H), 6.17 (t, J=8.7 Hz, 1H), 5.65 (d, J=6.6
Hz, 1H), 5.39 (bd, J=9.6 Hz, 1H), 5.26 (bd, 1H), 4.93 (d, J=8.4 Hz,
1H), 4.67 (m, 3H), 4.28 (m, 5H), 3.83 (d, J=6.0 Hz, 1H), 3.44 (d,
J=5.1 Hz, 1H), 2.77 (m, 1H), 2.50 (m, 1H), 2.36 (s, 3H), 2.29 (d,
J=8.4 Hz, 2H), 2.13 (bs, 3H), 2.01 (s, 3H), 1.82 (m, 2H), 1.74 (s,
3H), 1.33 (s, 9H), 1.18 (s, 3H), 1.16 (s, 3H) ; .sup.13C NMR
(CDCl.sub.3, 75.5 MHz) .delta. 201.5, 171.7, 170.3, 167.0, 155.4,
141.3, 133.7, 132.7, 130.2, 129.0, 128.8, 128.7, 128.1, 126.8,
83.8, 81.3, 80.2, 78.6, 75.0, 74.4, 74.0, 73.6, 72.3, 60.6, 57.4,
56.2, 47.2, 43.2, 35.3, 32.6, 28.2, 26.5, 22.6, 21.0, 15.5, 14.7,
10.8.
[0538] FABMS (NOBA) M+Na calcd for C.sub.47H.sub.59NO.sub.16SNa
948. Found: 948.
Example 17.
3'-N-debenzoyl-3'-N-(t-butoxycarbonyl)-7-O-methylthiomethyl-3'-
-desphenyl-3'-isobutenylpaclitaxel
[0539] 96
[0540] To a solution of 7-O-methylthiomethylbaccatin III (1.5 g,
2.3 mmol) in 30 mL of THF was added n-BuLi (1.0 mL, 2.5M in hexane,
2.5 mmol) at -60.degree. C. and stirred for 10 minutes. Then a
solution of
(.+-.)-cis-3-triethylsilyloxy-4-isobutenyl-N-t-butoxycarbonylazetidin-2-o-
ne (3.3 g, 9.3 mmol) in 10 mL of THF was added dropwise. The
solution was then stirred at 0.degree. C. for 30 min. and quenched
with sat. NH.sub.4Cl solution and extracted with ethyl acetate. The
solution was dried over MgSO.sub.4and concentrated and the residue
chromatographed over silica gel (3:1 hexane/ethyl acetate). The
product was dissolved in 100 mL of THF and was shaken with
Bu.sub.4NF (2.3 mL, 1.0M in THF, 2.3 mmol) diluted with ethyl
acetate and washed with brine. The solution was dried over
MgSO.sub.4 and concentrated and the residue chromatographed over
silica gel (1.5:1-hexane/ethyl acetate) to give 1.6 g of the title
product (78%); IR(film) 3452 (br), 1724, 1370, 1242, 1096, 1066
cm.sup.-; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta. 8.07 (d, J=7.2
Hz, 2H), 7.59 (t, J=7.5 Hz, 1H), 7.45 (t, J=7.8 Hz, 2H), 6.54 (s,
1H), 6.11 (t, J=9.3 Hz, 1H), 5.66 (d, J=6.0 Hz, 1H), 5.29 (d, J=6.0
Hz, 1H), 4.94 (d, J=8.1 Hz, 1H), 4.75 (m, 2H), 4.64 (ABq, J=12.0,
2.7 Hz, 2H), 4.29 (m, 2H), 4.20 (m, 2H), 3.86 (d, J=6.0 Hz, 1H),
3.37 (bd, 1H), 2.79 (m, 1H), 2.35 (s, 6H), 2.16 (s, 3H), 2.10 (s,
3H), 2.04 (s, 3H), 1.82 (m, 1H), 1.74 (s, 9H), 1.34 (s, 9H), 1.23
(s, 3H), 1.20 (s, 3H); .sup.13C NMR (CDCl.sub.3, 75.5 Hz) .delta.
202, 170.2, 169.2, 166.9, 155.4, 140.6, 138.0, 133.7, 133.1, 130.1,
129.2, 128.6, 120.6, 83.8, 81.2, 79.9, 78.7, 77.2, 76.1, 75.5,
74.6, 74.0, 73.7, 72.2, 57.4, 51.5, 47.1, 43.2, 35.4, 32.9, 28.2,
26.4, 25.8, 22.4, 21.0, 18.6, 15.1, 14.8, 10.9.
[0541] FABMS (NOBA) M+H calcd for C.sub.45H.sub.62NSO.sub.15 888.
Found: 888.
Example 18.
7-O-methylthiomethyl-3'-desphenyl-3'-isobutenylpaclitaxel
[0542] The title compound was prepared as in Example 17 from
7-O-methylthiomethylbaccatin III and
(.+-.)-cis-3-triethylsilyloxy-4-isob-
utenyl-N-benzoylazetidin-2-one.
Example 19.
3'-Desphenyl-3'-(2-furyl)-2'-O-ethyloxycarbonyl-7-O-methylthio-
methylpaclitaxel.
[0543] The title compound can be prepared from
(3R,4R)-1-benzoyl-4-(2-fury- l)-3-triethylsilyloxy-2-azetidinone
and 7-O-methylthiomethylbaccatin III following the procedures
decribed in Example 7(a) and 7(b).
Example 20.
2'-O-n-propylcarbonyl-7-O-phosphonooxymethylpaclitaxel.
[0544] (a) preparation of 2'-O-n-propylcarbonylpaclitaxel. 97
[0545] To a solution of paclitaxel (15.0 g, 17.5 mmol) and
diisopropylethyl amine (18.3 mL, 105 mmol) in dichloromethane (175
mL) cooled to 0.degree. C. was added butyryl chloride (5.49 mL,
52.4 mmol) dropwise over 2 min. The reaction mixture was then
warmed to room temperature and stirred for 16 h. The reaction
mixture was then partitioned between ethyl acetate and a saturated
aqueous ammonium chloride solution. The organic phase was then
washed with a saturated sodium bicarbonate solution followed by
brine, dried over sodium sulfate and concentrated in vacuo. The
residual oil was purified using flash chromatography (eluted with
hexanes:ethyl acetate) to provide the title ester (15.9 g, 98%
yield) as a white solid; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta.
8.13-8.05 (2H, m), 7.75-7.65 (2H, m), 7.62-7.30 (11H, m), 6.88 (1H,
d, J=9.0 Hz), 6.26 (1H, s), 6.23 (1H, dd, J=8.4 Hz), 5.92 (1H, dd,
J=9.3, 6.0 Hz), 5.65 (1H, d, J=7.1 Hz), 5.48 (1H, d, J=3.2 Hz),
4.94 (1H, d, J=7.9 Hz), 4.21 (1H, dd, J=10.4, 6.5 Hz), 4.28 (1H, d,
J=8.4 Hz), 4.17 (1H, d, J=8.4 Hz), 3.78 (1H, d, J=7.0 Hz),
2.64-1.02 (26H, m, including singlets at 2.43, 2.19, 1.91, 1.65,
1.65, 1.20, 1.10, 3H each), 0.87 (3H, dd, J=8.2 Hz).
[0546] (b) preparation of
2'-O-n-propylcarbonyl-7-O-methylthiomethylpaclit- axel. 98
[0547] To a solution of 2'-O-n-propylcarbonylpaclitaxel (14.4 g,
15.6 mmol) and dimethyl sulfide (9.23 mL, 124.8 mmol) in
acetonitrile (312 mL) cooled to -40.degree. C. was added benzoyl
peroxide (15.1 g, 62.3 mmol) and the reaction mixture was warmed to
room temperature over 1 h. At this time a TLC (eluted with
hexanes:ethyl acetate, 1:1) indicated the reaction was complete.
The reaction mixture was then diluted with ethyl acetate and the
resulting organic solution was washed three times with a saturated
sodium bicarbonate solution then brine. The organic phase was then
dried over sodium sulfate and concentrated in vacuo. The residual
oil was purified via flash chromatography (eluted with hexanes:
ethyl acetate) to provide the title compound (14.4 g, 93%) as a
white solid; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta. 8.21-8.19
(2H, m), 7.72-7.70 (2H, m), 7.62-7.26 (11H, m), 6.92 (3H, s), 6.20
(1H, dd, J=8.4 Hz), 5.92 (1H, dd, J=9.0, 3.1 Hz), 5.66 (1H, d,
J=6.9 Hz), 5.51 (1H, d, J=3.2 Hz), 4.92 (1H, d, J=8.2 Hz),
4.68-4.59 (2H, m), 4.32-4.26 (2H, m), 4.15 (1H, d, J=8.3 Hz), 3.86
(1H, d, J=6.8 Hz), 2.77 (1H, m), 2.50-1.05 (25H, m), 0.87 (3H, dd,
J=7.3 Hz).
[0548] (c) preparation of
2'-O-n-propylcarbonyl-7-O-(dibenzylphosphonooxym- ethyl)paclitaxel.
99
[0549] N-Iodosuccinimide (4.9 g, 21.8 mmol) was added in one
portion to a solution of
2'-O-n-propylcarbonyl-7-O-methylthiomethylpaclitaxel (10.7 g, 11.0
mmol), dibenzylphosphate (15.3 g, 55.0 mmol) and 5 g of oven dried
3 Angstrom sieves in THF (200 mL) at room temperature and the
resulting mixture was stirred for 1 h. At this time a TLC analysis
(eluted with hexanes:ethyl acetate, 1:1) indicated the reaction was
complete. The reaction mixture was then diluted to twice the
initial volume with ethyl acetate and filtered through a bed of
celite. The filtrate was then poured into a saturated sodium
bicarbonate solution containing 1% sodium thiosulfate by weight.
The organic layer was then washed four times with a saturated
aqueous sodium bicarbonate solution followed by brine. The aqueous
layer was then back extracted with ethyl acetate and the combined
organics were dried over sodium sulfate and concentrated in vacuo.
The residual oil was purified via flash chromatography
(hexanes:ethyl acetate) to provide the title dibenzylphosphate (9.9
g, 76% yield) as a white solid; .sup.1H-NMR (CDCl.sub.3, 300 MHz)
.delta. 8.10-8.08 (2H, m), 7.74-7.71 (2H, m), 7.61-7.25 (21H, m),
6.94 (1H, d, J=9.0 Hz), 6.31 (1H, s), 6.20 (1H, dd, J=8.7 Hz), 5.91
(1H, dd, J=9.0, 3.1 Hz), 5.64 (1H, d, J=6.9 Hz), 5.49 (1H, d, J=3.0
Hz), 5.39 (1H, dd, J=6.6 Hz), 5.05-4.98 (5H, m), 4.86 (1H, d, J=8.4
Hz), 4.26-4.12 (3H, m), 3.84 (1H, d, J=6.8 Hz), 2.82-2.71 (1H, m),
2.52-1.05 (26 H, m, including singlets at 2.43, 2.18, 1.97, 1.69,
1.22, 1.20, 3H each) 0.90-0.85 (3H, dd, J=7.3 Hz).
[0550] (d) preparation of
2'-O-n-propylcarbonyl-7-O-phosphonooxymethylpacl- itaxel. 100
[0551] To a nitrogen purged Parr hydrogenation vessel was added 2.5
g of 10% palladium-on-carbon followed by neat ethyl acetate (150
mL) and a solution of
2'-O-n-propylcarbonyl-7-O-(dibenzylphosphonooxymethyl)paclita- xel
(4.9 g, 4.14 mmol) in ethyl acetate (40 mL). The reaction vessel
was then fixed to a Parr hydrogenator, placed under vacuum, then
pressurized with a hydrogen atmosphere of 50 psi. The heterogenous
mixture was then shaken for 5 h after which time a TLC analysis
(eluted with hexanes:ethyl acetate) indicated the consumption of
starting material. The reaction mixture was then placed under
vacuum and subsequently purged with nitrogen. The mixture was then
filtered using a sintered glass funnel and the filtrate
concentrated in vacuo to provide the title compound (3.7 g, 91%
yield) which was pure by .sup.1H-NMR analysis.
[0552] (e) preparation of
2'-O-n-propylcarbonyl-7-O-phosphonooxymethylpacl- itaxel
triethanolamine salt.
[0553] To a solution of
2'-O-n-propylcarbonyl-7-O-phosphonooxymethylpaclit- axel (1.1 g,
1.09 mmol) in dichloromethane (50 mL) was added a 0.1M solution of
triethanolamine (10.9 mL, 1.09 mL) in ethyl acetate and the
resulting mixture was stirred for 5 min at room temperature. The
reaction mixture was then concentrated in vacuo and the resulting
white solid was purified by first dissolving the crude material in
a minimum amount of a methylene chloride-ethyl acetate mixture.
Hexanes were then added to this solution and the desired amine salt
precipitated as a white solid. The mixture was then decanted to
provide the amine salt as a white solid which had an observed HPLC
purity greater than 95%; .sup.1H-NMR (Acetone-d.sub.6, D.sub.2O,
300 MHz) .delta. 8.09-8.07 (2H, m), 7.86-7.84 (2H), 7.69-7.24 (1H,
dd, J=7.5 Hz), 6.36 (1H, s), 6.05 (1H, dd, J=8.4 Hz), 5.85 (1H, d,
J=6.7 Hz), 5.61 (1H, d, J=7.0 Hz), 5.49 (1H, d, J=6.9 Hz),
5.15-5.13 (1H, m), 4.98 (1H, d, J=8.2 Hz), 4.87 (1H, dd, J=12.1 Hz,
6.4 Hz), 4.12 (bs, 2H), 3.89-3.80 (7H, m), 3.36-3.30 (6H, m),
2.95-2.93 (1H, m), 2.42-1.50 (25H, m, including singlets at 2.42,
2.22, 1.93, 1.66, 3H each), 1.13 (bs, 6H), 0.86-0.81 (2H, dd, J=7.4
Hz).
Example 21.
2'-O-Methylcarbonyl-7-O-phosphonooxymethylpaclitaxel.
[0554] (a) preparation of 2'-O-acetylpaclitaxel. 101
[0555] To a solution of paclitaxel (8.0 g, 9.37 mmol) and
diisopropylethyl amine (4.89 mL, 28.1 mmol) in dichloromethane (140
mL) cooled to 0.degree. C. was added acetyl chloride (1.0 mL, 14.1
mmol) dropwise over 2 min. The reaction mixture was then warmed to
room temperature and stirred for 10 h. The reaction mixture was
then partitioned between ethyl acetate and a saturated aqueous
ammonium chloride solution. The organic phase was then washed with
a saturated sodium bicarbonate solution followed by brine, dried
over sodium sulfate and concentrated in vacuo. The residual oil was
purified using flash chromatography (eluted with hexanes: ethyl
acetate) to provide 2'-O-acetylpaclitaxel (7.7 g, 92%) as a white
solid; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta. 8.10-8.08 (2H, m),
7.92-7.90 (1H, m), 7.89-7.70 (2H, m), 7.60-7.29 (11H, m), 6.94 (1H,
d, J=9.2 Hz), 6.26 (1H, s), 6.23 (1H, dd, J=9.5 Hz), 5.93 (1H, dd,
J=9.2, 3.1 Hz), 5.65 (1H, d, J=7.0 Hz), 5.48 (1H, d, J=3.2 Hz),
4.94 (1H, d, J=7.8 Hz), 4.42 (1H, dd, J=10.8 Hz, 6.6 Hz), 4.28 (1H,
d, J=8.4 Hz), 4.16 (1H, d, J=8.4 Hz), 3.78 (1H, d, J=6.9 Hz),
2.60-1.02 (25H, m, including singlets at 2.42, 2.19, 2.12, 1.90,
1.65, 1.25, 1.11, 3H each).
[0556] (b) preparation of
2'-O-acetyl-7-O-methylthiomethylpaclitaxel. 102
[0557] To a solution of 2'-O-acetylpaclitaxel (7.7 g, 8.60 mmol)
and dimethyl sulfide (5.1 mL, 68.8 mmol) in acetonitrile (200 mL)
cooled to -40.degree. C. was added benzoyl peroxide (8.3 g, 34.4
mmol) and the reaction mixture was warmed to room temperature over
1 h. At this time a TLC (eluted with hexanes:ethyl acetate, 1:1)
indicated the reaction was complete. The reaction mixture was then
diluted with ethyl acetate and the resulting organic solution was
washed three times with a saturated sodium bicarbonate solution
then brine. The organic phase was then dried over sodium sulfate
and concentrated in vacuo. The residual oil was purified via flash
chromatography (hexanes: ethyl acetate) to provide the title
methylthiomethylether (7.39 g, 90%) as a white solid; .sup.1H-NMR
(CDCl.sub.3, 300 MHz) .delta. 8.10-8.08 (2H, m), 7.77-7.73 (2H, m),
7.65-7.26 (1H, m), 6.53 (3H, 2), 6.20 (1H, dd, J=8.3 Hz), 5.92 (1H,
dd, J=12.2, 3.1 Hz), 5.67 (1H, d, J=7.0 Hz), 5.51 (1H, d, J=3.2
Hz), 4.94 (1H, d, J=8.2 Hz), 4.69-4.60 (3H, m), 4.33-4.28 (2H, m),
4.27 (1H, d, J=8.4 Hz), 3.86 (1H, d, J=6.9 Hz), 2.84-2.74 (1H, m),
2.50-1.1 (28H, m, including singlets at 2.41, 2.15, 2.13, 2.11,
2.06, 1.73, 1.18, 1.15, 3H each).
[0558] (c) preparation of
2'-O-acetyl-7-O-(dibenzylphosphonooxymethyl)pacl- itaxel. 103
[0559] N-Iodosuccinimide (1.75 g, 7.85 mmol) was added in one
portion to a solution of 2'-O-acetyl-7-O-methylthiomethylpaclitaxel
(5.0 g, 5.23 mmol), dibenzylphosphate (7.3 g, 26.1 mmol) and 5 g of
oven dried 3 Angstrom sieves in THF (104 mL) at room temperature
and the resulting mixture was stirred for 1.5 h. At this time a TLC
analysis (eluted with hexanes:ethyl acetate, 1:1) indicated the
reaction was complete. The reaction mixture was then diluted to
twice the volume with ethyl acetate and filtered through a bed of
celite. The filtrate was then poured into a saturated sodium
bicarbonate solution containing 1% sodium thiosulfate by weight.
The organic layer was then washed four times with a saturated
aqueous sodium bicarbonate solution followed by brine. The aqueous
layers were then back extracted with ethyl acetate and the combined
organics were dried over sodium sulfate and concentrated in vacuo.
The residual oil was purified via flash chromatography (eluted with
hexanes:ethyl acetate) to provide the title dibenzylphosphate (4.9
g, 80%) as a white solid.
[0560] (b) preparation of
2'-O-acetyl-7-O-phosphonooxymethylpaclitaxel. 104
[0561] To a nitrogen purged Parr hydrogenation vessel was added 700
mg of 10% palladium-on-carbon followed by neat ethyl acetate (130
mL) and a solution of
2-O-acetyl-7-O-(dibenzylphosphonooxymethyl)paclitaxel (1.0 g, 0.84
mmol) in ethyl acetate (40 mL). The reaction vessel was then fixed
to a Parr hydrogenator, placed under vacuum, then pressurized with
a hydrogen atmosphere of 50 psi. The reaction mixture was then
shaken for 6 h after which time a TLC analysis (eluted with
hexanes:ethyl acetate) indicated the consumption of the starting
material. The reaction mixture was then placed under vacuum and
subsequently purged with nitrogen. The heterogenous solution was
then filtered using a sintered glass funnel and the filtrate
concentrated in vacuo to provide a white solid (848 mg) which
.sup.1H-NMR analysis showed to be a mixture of the desired title
compound (50%) and 2-O-acetylpaclitaxel.
[0562] (e) preparation of
2'-O-acetyl-7-O-phosphonooxymethylpaclitaxel triethanolamine
salt.
[0563] To a solution of
2'-O-acetyl-7-O-phosphonooxymethylpaclitaxel (424 mg, 0.42 mmol)
and the aforementioned side product 2'-O-acetylpaclitaxel in
dichloromethane (15 mL) was added a 0.1M solution of
triethanolamine (3.7 mL, 3.8 mmol) in ethyl acetate and the
resulting mixture was stirred for 10 min at room temperature. The
reaction mixture was then concentrated in vacuo and the resulting
white solid was purified by C18 chromatography (water:acetonitrile
2.3:1) to provide the desired amine salt (310 mg, 72%) which had an
observed HPLC purity greater than 96%; .sup.1H-NMR
(Acetone-d.sub.6, D.sub.2O, 300 MHz) .delta. 8.08-8.05 (2H, m),
7.86-7.83 (2H, m), 7.69-7.24 (1H, m), 7.23 (1H, dd, J=7.4 Hz), 6.35
(1H, s), 6.02 (1H, dd. J=8.3 Hz), 5.79 (1H, d, J=6.9 Hz), 5.59 (1H,
d, J=7.1 Hz), 5.45 (1H, d, J=6.9 Hz), 5.12 (1H, dd, J=6.4 Hz), 4.95
(1H, d, J=8.4 Hz), 4.86 (1H, dd, J=11.5, 6.5 Hz), 4.24-4.18 (1H,
m), 4.12 (2H, bs), 3.92-3.89 (6H, m), 3.80-3.77 (1H, m), 3.46-3.43
(6H, m), 3.00-2.89 (1H, m), 2.39-1.65 (21H including singlets at
2.39, 2.14, 2.12, 1.92, 1.65, 1.11 3H each) 1.11 (6H, bs).
Example 22.
2'-O-methoxycarbonyl-7-O-phosphonooxymethylpaclitaxel.
[0564] (a) preparation of 2'-O-methoxycarbonylpaclitaxel. 105
[0565] To a solution of paclitaxel (8.0 g, 9.60 mmol) and
diisopropylethyl amine (5.0 mL, 28.8 mmol) in dichloromethane (96
mL) cooled to 0.degree. C. was added chloromethyl carbonate (1.11
mL, 14.4 mmol) dropwise over 2 min. The reaction mixture was then
warmed to room temperature and stirred for 20 h. The reaction
mixture was then partitioned between ethyl acetate and a saturated
aqueous ammonium chloride solution. The organic phase was then
washed with a saturated sodium bicarbonate solution, followed by
brine, dried over sodium sulfate and concentrated in vacuo. The
residual oil was purified using flash chromatography (hexanes:
ethyl acetate) to provide the title compound (7.8 g, 91.3%) as a
white solid; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta. 8.12-8.09
(2H, m), 7.72-7.70 (2H, m), 7.62-7.30 (1H, m), 6.96 (1H, d, J=9.3
Hz), 629-6.23 (3H, m), 5.95 (1H, dd, J=9.3, 2.5 Hz), 5.66 (1H, d,
J=7.1 Hz), 5.38 (1H, d, J=2.6 Hz), 4.94 (1H, d, J=7.8 Hz), 4.41
(1H, dd, J=10.8, 6.6 Hz), 4.28 (1H, d, J=8.4 Hz), 4.17 (1H, d,
J=8.4 Hz), 3.79-3.78 (3H, m), 2.60-1.04 (22H, m, including singlets
at 2.43, 2.19, 1.90, 1.65, 1.22, 1.10, 3H each).
[0566] (b) preparation of
2'-O-methoxycarbonyl-7-O-methylthiomethylpaclita- xel. 106
[0567] To a solution of 2'-O-methoxycarbonylpaclitaxel(7.4 g, 8.10
mmol) and dimethyl sulfide (4.8 mL, 64.8 mmol) in acetonitrile (162
mL) cooled to -40.degree. C. was added benzoyl peroxide (7.48 g,
32.4 mmol) and the reaction mixture was warmed to room temperature
over 1 h. At this time a TLC analysis (eluted with hexanes:ethyl
acetate, 1:1) indicated the reaction was complete. The reaction
mixture was then diluted with ethyl acetate and the resulting
organic solution was washed three times with a saturated sodium
bicarbonate solution then brine. The organic phase was then dried
over sodium sulfate and concentrated in vacuo. The residual oil was
purified via flash chromatography (eluted with hexanes: ethyl
acetate) to provide the title compound (7.4 g, 95%) as a white
solid; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta. 8.25-8.23 (2H, m),
7.87-7.77 (2H, m), 7.60-7.30 (1H, m), 6.93 (1H, d, J=9.2 Hz), 6.53
(1H, s), 6.25 (1H, dd, J=8.2 Hz), 5.95 (1H, dd, J=11.7, 2.4 Hz),
5.68 (1H, d, J=6.9 Hz), 5.40 (1H, d, J=2.6 Hz), 4.95 (1H, d, J=8.1
Hz), 4.69-4.60 (2H, m), 4.31-4.26 (2H, m), 4.16 (1H, d, J=8.4 Hz),
3.86 (1H, J=6.9 Hz), 3.79 (3H, s), 2.84-2.74 (1H, m), 2.43-1.10
(25H, including singlets at 2.44, 2.15, 2.10, 2.08, 1.73, 1.19,
1.16 3H).
[0568] (c) preparation of
2'-O-methoxycarbonyl-7-O-(dibenzylphosphonooxyme- thyl)paclitaxel
107
[0569] N-Iodosuccinimide (1.74 g, 7.77 mmol) was added in one
portion to a solution of 2'-O-methoxycarbonylpaclitaxel(5.04 g,
5.18 mmol), dibenzylphosphate (7.2 g, 25.8 mmol) and 5 g of oven
dried 3 Angstrom sieves in THF (100 mL) at room temperature and the
resulting mixture was stirred for 1.5 h. At this time a TLC
analysis (eluted with hexanes:ethyl acetate, 1:1) indicated the
reaction was complete. The reaction mixture was then diluted to
twice the volume with ethyl acetate and filtered through a bed of
celite. The filtrate was then poured into a saturated sodium
bicarbonate solution containing 1% sodium thiosulfate by weight.
The organic layer was then washed four times with a saturated
aqueous sodium bicarbonate solution followed by brine. The aqueous
layer was then back extracted with ethyl acetate and the combined
organics were dried over sodium sulfate and concentrated in vacuo.
The residual oil was purified via flash chromatography (eluted with
hexanes:ethyl acetate) to provide the title compound (5.1 g, 96%)
as a white solid; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta.
8.12-8.08 (2H, m), 7.73-7.70 (2H, m), 7.62-7.27 (21H, m), 7.00 (1H,
d, J=9.2 Hz), 6.31 (1H, s), 6.24-6.21 (1H, m), 5.96- 5.92 (1H, m),
5.66-5.64 (1H, m), 5.40-5.36 (2H, m), 5.05-4.93 (5H, m), 4.87-4.84
(1H, m), 4.29-4.05 (3H, m), 3.85-3.83 (1H, m), 3.77 (3H, s),
2.81-2.71 (1H, m), 2.62-1.05 (22H, m, including singlets at 2.43,
2.19, 2.01, 1.73, 1.22, 1.15, 3H each).
[0570] (d) preparation of
2'-O-methoxycarbonyl-7-O-phosphonooxymethylpacli- taxel. 108
[0571] To a nitrogen purged Parr hydrogenation vessel was added 1.3
g of 10% palladium-on-carbon followed by neat ethyl acetate (140
mL) and a solution of
2-O-methoxycarbonyl-7-O-(dibenzylphosphonooxymethyl)paclitaxe- l
(3.4 g, 3.32 mmol) in ethyl acetate (40 mL). The reaction vessel
was then fixed to a Parr hydrogenator, placed under vacuum, then
pressurized with a hydrogen atmosphere of 50 psi. The resulting
mixture was shaken for 8.5 h after which time a TLC analysis
(eluted with hexanes:ethyl acetate) indicated the consumption of
starting material. The reaction mixture was then placed under
vacuum and subsequently purged with nitrogen. The heterogenous
solution was then filtered using a sintered glass funnel and the
filtrate concentrated in vacuo to provide a white solid (2.9 g)
which .sup.1H-NMR analysis showed to be a mixture of the desired
title product (67%) and 2'-O-methoxycarbonylpaclitaxel (33%).
[0572] (e) preparation of
2'-O-methoxycarbonyl-7-O-phosphonooxymethylpacli- taxel
triethanolamine salt.
[0573] To a solution of
2'-O-methoxycarbonyl-7-O-phosphonooxymethylpaclita- xel (1.91 g,
1.87 mmol) and the aforementioned side product
2'-O-methoxycarbonylpaclitaxel in dichloromethane (11 mL) was added
a 0.1M solution of triethanolamine (18.9 mL, 1.89 mmol) in ethyl
acetate and the resulting mixture was stirred for 5 min at room
temperature. The reaction mixture was then concentrated in vacuo
and the resulting white solid was purified by C18 chromatography
(eluted with water:acetonitrile 2.3:1) to provide a lyophilized
triethanolamine salt which had an observed HPLC purity greater than
97%; .sup.1H-NMR (Acetone-d.sub.6, D.sub.2O, 300 MHz) .delta.
8.08-8.06 (2H, m), 7.88-7.55 (2H, m), 7.69-7.24 (11H, m), 7.24 (1H,
dd, J=7.3 Hz), 6.36 (1H, m), 6.05 (1H, dd, J=8.8 Hz), 5.82 (1H, d,
J=6.8 Hz), 5.60 (1H, d, J=7.1 Hz), 5.46 (1H, d, J=6.9 Hz), 5.13
(1H, dd, J=6.5 Hz), 5.98 (1H, d, J=8.1 Hz), 4.87 (1H, dd, J=11.8
Hz, 6.3 Hz), 4.21 (1H, dd, J=10.3, 6.9 Hz), 4.13 (bs, 6H),
3.92-3.89 (6H, m), 3.81 (1H, d, J=7.02), 3.76 (3H, s), 3.46-3.42
(6H, m), 3.01-2.90 (1H, m), 2.42 (3H, s), 2.20-1.80 (10H, including
singlets at 2.20, 1.93), 1.66 (3H, s), 1.12 (6H, bs).
Example 23. preparation of
2'-O-phosphonooxymethoxymethyl-7-O-phosphonooxy-
methylpaclitaxel.
[0574] (a) preparation of 2'-O-methylthiomethoxymethylpaclitaxel.
109
[0575] Palladium (10%) on carbon (3 g) was added to a solution of
2'-O-methylthiomethoxymethyl-7-O-benzyloxycarbonylpaclitaxel (1.2
g, 1.11 mmol) in ethyl acetate (100 mL) and ethanol (70 mL) housed
in a Parr bottle. The vessel was affixed to a Parr apparatus and
the reaction mixture subjected to hydrogen at 50 psi. The reaction
mixture was shaken for 20.5 h, then filtered using a sintered glass
funnel. The filtrate was concentrated in vacuo and the residual oil
purified via flash chromatography (eluted with hexanes:ethyl
acetate) to provide the desired (0.98 g, 93%) as a solid.
.sup.1H-NMR (CDCl.sub.3, 300 MHz), .delta. 8.12-8.10 (2H, m),
7.76-7.73 (2H, m),7.61-7.27 (11H, m), 7.03 (1H, d, J=8.9 Hz),
6.40-6.27 (1H, m), 6.25 (1H, s), 5.80 (1H, dd, J=8.9, 2.4 Hz), 5.66
(1H, d, J=7.1 Hz), 4.98-4.94 (1H, m), 4.86-4.79 (2H, m), 4.75-4.68
(1H, m), 4.43-4.39 (1H, m), 4.31-4.26 (2H, m), 4.05 (1H, d, J=11.7
Hz), 3.78 (1H, d, J=7.1 Hz), 2.60-1.06 (25H, m, including singlets
at 2.45, 2.21, 2.02, 1.85, 1.66, 1.22, 1.11,-3H each).
[0576] (b) preparation of
2'-O-methylthiomethoxymethyl-7-O-methylthiomethy- lpaclitaxel.
110
[0577] To a solution of 2'-O-methylthiomethoxymethylpaclitaxel.
(0.98 g, 1.03 mmol) and dimethyl sulfide (0.6 mL, 8.11 mmol) in
acetonitrile (20 mL) cooled to -40.degree. C. was added benzoyl
peroxide (1.0 g, 4.13 mmol) and the reaction mixture was warmed to
room temperature over 30 min. At this time a TLC analysis (eluted
with hexanes:ethyl acetate, 1:1) indicated the reaction was
complete. The reaction mixture was then diluted with ethyl acetate
and the resulting organic solution was washed three times with a
saturated sodium bicarbonate solution then brine. The organic phase
was then dried over sodium sulfate and concentrated in vacuo. The
residual oil was purified via flash chromatography (eluted with
hexanes:ethyl acetate) to provide the title product (0.945 g, 91%)
as a white solid; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta.
8.13-8.11 (2H, m), 7.79-7.77 (2H, m), 7.61-7.29 (11H, m), 6.54 (1H,
s), 6.30-6.26 (1H, m), 5.83-5.80 (1H, m), 5.71-5.69 (1H, m),
5.01-4.66 (6H, m), 4.34-4.04 (5H, m), 3.88 (1H, d, J=6.6 Hz),
2.90-2.80 (1H, m), 2.55-1.05 (27H, m, including singlets at 2.51,
2.18, 2.11, 1.80, 1.21, 1.20, 3H each).
[0578] (c) preparation of
2'-O-dibenzylphosphonooxymethoxymethyl-7-O-(dibe-
nzylphosphonooxymethyl)paclitaxel. 111
[0579] N-Iodosuccinimide (0.615 g, 2.74 mmol) was added in one
portion to a solution
2'-O-methylthiomethoxymethyl-7-O-methylthiomethylpaclitaxel (0.92
g, 0.916 mmol), dibenzylphosphate (2.03 g, 7.30 mmol) and 1 g of
oven dried 3 Angstrom sieves in THF (18 mL) at room temperature and
the resulting mixture was stirred for 30 min. At this time a TLC
analysis (eluted with hexanes:ethyl acetate, 1:2) indicated the
reaction was complete. The reaction mixture was then diluted to
twice the volume with ethyl acetate and filtered through a bed of
celite. The filtrate was then poured into a saturated sodium
bicarbonate solution containing 1% sodium thiosulfate by weight.
The organic layer was then washed four times with a saturated
aqueous sodium bicarbonate solution followed by brine. The aqueous
layer was then back extracted with ethyl acetate and the combined
organics were dried over sodium sulfate and concentrated in vacuo.
The residual oil was purified via flash chromatography (eluted with
hexanes:ethyl acetate) to provide the title product (0.768 g, 58%)
as a white solid; .sup.1H-NMR (CDCl.sub.3, 300 MHz) .delta.
8.10-8.05 (2H, m), 7.80-7.74 (2H, m), 7.65-7.27 (11H, m), 6.30 (1H,
s), 6.25-6.18 (1H, m), 5.82 (1H, dd, J=9.1, 3.4 Hz), 5.63 (1H, dd,
J=6.9 Hz), 5.38 (1H, dd, J=6.6 Hz), 5.10-4.60 (15H, m), 4.30-4.10
(3H, m), 3.80 (1H, d, J=6.8 Hz), 2.85-2.65 (1H, m), 2.50-1.60 (22H,
m, including singlets at 2.47, 2.16, 1.91, 1.72, 1.88, 1.15, 3H
each).
[0580] (d) preparation of
2'-O-phosphonooxymethoxymethyl-7-O-phosphonooxym- ethylpaclitaxel
112
[0581] To a nitrogen purged Parr hydrogenation vessel was added 1.3
g of 10% palladium-on-carbon followed by neat ethyl acetate (110
mL) and a solution of
2'-O-dibenzylphosphonooxymethoxymethyl-7-O-(dibenzylphosphono-
oxymethyl)paclitaxel (0.721 g, 0.498 mmol) in ethyl acetate (40
mL). The reaction vessel was then fixed to a Parr hydrogenator,
placed under vacuum then pressurized with a hydrogen atmosphere of
50 psi. The heterogenous mixture was then shaken for 16 h after
which time a TLC analysis (eluted with hexanes:ethyl acetate)
indicated the consumption of starting material. The reaction
mixture was then placed under vacuum and subsequently purged with
nitrogen. The mixture was then filtered using a sintered glass
funnel and the filtrate concentrated in vacuo to provide the title
product (0.413 g) which was at 60% purity by HPLC analysis.
[0582] (e) preparation of
2'-O-phosphonooxymethoxymethyl-7-O-phosphonooxym- ethylpaclitaxel
bis-triethanolamine salt.
[0583] To a solution of crude of
2'-O-phosphonooxymethoxymethyl-7-O-phosph- onooxymethylpaclitaxel
(413 mg) in dichloromethane (10 mL) was added a 0.1M solution of
triethanolamine (7.6 mL, 0.076 mmol) in ethyl acetate and the
resulting mixture was stirred for 5 min at room temperature. The
reaction mixture was then concentrated in vacuo and the resulting
white solid was purified by C18 chromatography (eluted with water
acetonitrile, 9:1 to 5.6:1). Fractions of eluent containing the
desired salt in greater than 96% purity by HPLC were combined and
the acetonitrile was removed via rotary evaporation. The resulting
aqueous solution of was lyophylized to provide the desired salt
(0.210 g, 30% over 2 steps) as a white solid. .sup.1H-NMR
(Acetone-d.sub.6, D.sub.2O, 300 MHz) .delta. 7.97-7.94 (2H, m),
7.79-7.76 (2H, m), 7.12-7.07 (1H, m), 6.26 (1H, s), 5.89 (1H, dd,
J=8.6 Hz), 5.48 (1H, d, J=7.9 Hz), 5.00-4.79 (8H, m), 4.70 (1H, d,
J=8.1 Hz), 4.15-4.03 (3H, m), 3.74-3.66 (7H, m), 3.14-2.86 (8H, m),
2.33-1.00 (20H, m, including singlets at 2.33, 2.10, 1.88, 1.56,
1.02, 1.00, 3H each).
Additional Examples
[0584] The general procedures provided in the foregoing examples
and descriptions are followed in the preparation of the following
compounds within the scope of formula (A).
7 113 R.sup.I R.sup.II' R.sup.II R.sup.III R.sup.IV R.sup.V OH H
--OCH.sub.2OP(O)(OH).sub.2 AcO Ph 4- F--Ph-- 4-CH.sub.3--Ph
2-furanyl 2-thienyl (CH.sub.3).sub.2CH-- isobutenyl (2-methyl-1-
propenyl) * c-C.sub.3H.sub.6-- 3-furanyl 3-thienyl 2-propenyl
--OCH.sub.2OP(O)(OH).sub.2 H OH AcO Ph 4-CF.sub.3--Ph-- 2-furanyl
(CH.sub.3).sub.2CH-- 2-thienyl isobutenyl cyclopropyl 3-thienyl
3-furanyl 2-propenyl iosopropyl CH.sub.3CH.sub.2OC(O)O-- H
--OCH.sub.2OP(O)(OH).sub.2 AcO Ph 4-F--Ph-- 2-thienyl isopropyl
2-propenyl isobutenyl cyclopropyl 2-furanyl 3-furanyl 3-thienyl
--OCH.sub.2OP(O)(OH).sub.2 H OH OH (CH.sub.3).sub.3CO-- Ph H
CH.sub.3CH.sub.2OC(O)O-- OH H --OCH.sub.2OP(O)(OH).sub.2 OH
(CH.sub.3).sub.3CO-- Ph CH.sub.3CH.sub.2OC(O)O--
--OCH.sub.2OP(O)(OH).sub.2 H H AcO Ph Ph CH.sub.3CH.sub.2OC(O)O-- -
OH H --OCH.sub.2OP(O)(OH).sub.2 AcO Ph Ph CH.sub.3OC(O)O--
CH.sub.3CH.sub.2OC(O)O-- CH.sub.3(CH.sub.2).sub.2OC(O)O--
CH.sub.3(CH.sub.2).sub.3OC(O)O-- CCl.sub.3CH.sub.2OC(O)O--
CH.sub.3C(O)O-- CH.sub.3CH.sub.2(O)O--
CH.sub.3(CH.sub.2).sub.2C(O)O-- CH.sub.3(CH.sub.2).sub.3C(O)O--
PhC(O)O-- PhOC(O)O-- CH.sub.2.dbd.CHCH.sub.2OC(O)O--
PhCH.sub.2OC(O)O-- OH H OH --OCH.sub.2OP(O)(OH).sub.2 Ph Ph OH H H
--OCH.sub.2OP(O)(OH).sub.2 Ph Ph --OCH.sub.2OP(O)(OH).sub.2 H H H
(CH.sub.3).sub.3CO-- 4-CH.sub.3O--Ph OH H
--OCH.sub.2OP(O)(OH).sub.2 AcO (CH.sub.3).sub.3CO-- isobutenyl
2-propenyl cyclopropyl 3-furanyl 3-thienyl isopropyl cycltobutyl
isopropyl CH.sub.3OC(O)O-- H --OCH.sub.2OP(O)(OH).sub.2 AcO
(CH.sub.3).sub.3CO-- isobutenyl 2-propenyl cyclopropyl 3-furanyl
3-thienyl isopropyl cyclobutyl isopropyl CH.sub.3CH.sub.2OC(O)O-- H
--OCH.sub.2OP(O)(OH).sub.2 AcO (CH.sub.3).sub.3CO-- isobutenyl
2-propenyl cyclopropyl 3-furanyl 3-thienyl isopropyl cyclobutyl
isopropyl CH.sub.3(CH.sub.2).sub.2OC(O)O-- H
--OCH.sub.2OP(O)(OH).sub.2 AcO (CH.sub.3).sub.3CO-- isobutenyl
2-propenyl cyclopropyl 3-furanyl 3-thienyl isopropyl cyclobutyl
isopropyl CH.sub.3(CH.sub.2).sub.3OC(O)O-- H
--OCH.sub.2OP(O)(OH).sub.2 AcO (CH.sub.3).sub.3CO-- isobutenyl
2-propenyl cyclopropyl 3-furanyl 3-thienyl isopropyl cyclobutyl
isopropyl CCl.sub.3CH.sub.2OC(O)O-- H --OCH.sub.2OP(O)(OH).sub.2
AcO (CH.sub.3).sub.3CO-- isobutenyl 2-propenyl cyclopropyl
3-furanyl 3-thienyl isopropyl cyclobutyl isopropyl CH.sub.3C(O)O--
H --OCH.sub.2OP(O)(OH).sub.2 AcO (CH.sub.3).sub.3CO-- isobutenyl
2-propenyl cyclopropyl 3-furanyl 3-thienyl isopropyl cyclobutyl
isopropyl CH.sub.3CH.sub.2(O)O-- H --OCH.sub.2OP(O)(OH).sub.2 AcO
(CH.sub.3).sub.3CO-- isobutenyl 2-propenyl cyclopropyl 3-furanyl
3-thienyl isopropyl cyclobutyl isopropyl
CH.sub.3(CH.sub.2).sub.2C(O)O-- H --OCH.sub.2OP(O)(OH).sub.2 AcO
(CH.sub.3).sub.3CO-- isobutenyl 2-propenyl cyclopropyl 3-furanyl
3-thienyl isopropyl cyclobutyl isopropyl
CH.sub.3(CH.sub.2).sub.3C(O)O-- H --OCH.sub.2OP(O)(OH).sub.2 AcO
(CH.sub.3).sub.3CO-- isobutenyl 2-propenyl cyclopropyl 3-furanyl
3-thienyl isopropyl cyclobutyl isopropyl PhC(O)O-- H
--OCH.sub.2OP(O)(OH).sub.2 AcO (CH.sub.3).sub.3CO-- isobutenyl
2-propenyl cyclopropyl 3-furanyl 3-thienyl isopropyl cyclobutyl
isopropyl PhOC(O)O-- H --OCH.sub.2OP(O)(OH).sub.2 AcO
(CH.sub.3).sub.3CO-- isobutenyl 2-propenyl cyclopropyl 3-furanyl
3-thienyl isopropyl cyclobutyl isopropyl
CH.sub.2.dbd.CHCH.sub.2OC(O)O-- H --OCH.sub.2OP(O)(OH).sub.2 AcO
(CH.sub.3).sub.3CO-- isobutenyl 2-propenyl cyclopropyl 3-furanyl
3-thienyl isopropyl cyclobutyl isopropyl PhCH.sub.2OC(O)O-- H
--OCH.sub.2OP(O)(OH).sub.2 AcO (CH.sub.3).sub.3CO-- isobutenyl
2-propenyl cyclopropyl 3-furanyl 3-thienyl isopropyl cyclobutyl
isopropyl --OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OP(O)(OH).sub.2
AcO CH.sub.3CH.sub.2CH.sub.2CH.sub.2O-- 2-furanyl 3-furanyl
isobutenyl 2-propenyl cyclopropyl cyclobutyl 3-thienyl 2-thienyl
isopropyl OH H --OCH.sub.2OP(O)(OH).sub.2 AcO
CH.sub.3CH.sub.2CH.sub.2CH.sub.2O-- 2-furanyl 3-furanyl isobutenyl
2-propenyl cyclopropyl cyclobutyl 3-thienyl 2-thienyl isopropyl
--OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OP(O)(OH).sub.2 AcO
isopropyloxy 2-furanyl 3-furanyl 2-thienyl isobutenyl 2-propenyl
cyclopropyl cyclobutyl 3-thienyl isopropyl OH H
--OCH.sub.2OP(O)(OH).sub.2 AcO isopropyloxy 2-furanyl 3-furanyl
2-thienyl isobutenyl 2-propenyl cyclopropyl cyclobutyl 3-thienyl
isopropyl OH H --OCH.sub.2OCH.sub.2OP(O)(OH)- .sub.2 AcO
(CH.sub.3).sub.3CO-- 2-furanyl CH.sub.3OC(O)O--
CH.sub.3CH.sub.2OC(O)O-- CH.sub.3(CH.sub.2).sub.2OC(O)O--
CH.sub.3(CH.sub.2).sub.3OC(O)O-- CCl.sub.3CH.sub.2OC(O)O--
CH.sub.3C(O)O-- CH.sub.3CH.sub.2(O)O--
CH.sub.3(CH.sub.2).sub.2C(O)O-- CH.sub.3(CH.sub.2).sub.3C(O)O--
PhC(O)O-- PhOC(O)O-- CH.sub.2.dbd.CHCH.sub.2OC(O)O--
PhCH.sub.2OC(O)O-- --OCO.sub.2CH.sub.2CH.sub.3 H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 AcO (CH.sub.3).sub.3CO--
3-furanyl isobutenyl 2-propenyl 2-thienyl 3-thienyl cyclopropyl
isopropyl OH H --OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 AcO
(CH.sub.3).sub.3CO-- 2-furanyl isobutenyl 2-thienyl 2-propenyl
isopropyl cyclopropyl 3-thienyl 3-furanyl
--OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OCH.sub.2OP(O)(- OH).sub.2
AcO CH.sub.3CH.sub.2CH.sub.2CH.sub.2O-- 2-furanyl
--OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OCH.sub.2OP(O)(OH).sub.2
AcO isopropyloxy 2-furanyl --OCO.sub.2CH.sub.2CH.sub.3 H
--OCH.sub.2OP(O)(OH).sub.2 --OCO.sub.2CH.sub.3 (CH.sub.3).sub.3CO--
2-furanyl 3-furanyl 3-thienyl isopropyl cyclopropyl isobutenyl
2-thienyl 2-propenyl OH H --OCH.sub.2OP(O)(OH).sub.2
--OCO.sub.2CH.sub.3 (CH.sub.3).sub.3CO-- 2-furanyl 3-furanyl
3-thienyl isopropyl cyclopropyl isobutenyl 2-thienyl 2-propenyl
--OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OP(O)(OH).sub.2 OMe
(CH.sub.3).sub.3CO-- 2-furanyl 3-furanyl 3-thienyl isopropyl
cyclopropyl isobutenyl 2-thienyl 2-propenyl OH H
--OCH.sub.2OP(O)(OH).sub.2 OMe (CH.sub.3).sub.3CO-- 2-furanyl
3-furanyl 3-thienyl isopropyl cyclopropyl isobutenyl 2-thienyl
2-propenyl --OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OP(O)(OH).sub.-
2 --OC(O)Ph (CH.sub.3).sub.3CO-- 2-furanyl 3-furanyl 3-thienyl
isopropyl cyclopropyl isobutenyl 2-thienyl 2-propenyl OH H
--OCH.sub.2OP(O)(OH).sub.2 --OC(O)Ph (CH.sub.3).sub.3CO-- 2-furanyl
3-furanyl 3-thienyl isopropyl cyclopropyl isobutenyl 2-thienyl
2-propenyl --OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OP(O)(OH).sub.-
2 --OCO.sub.2CH.sub.3 Ph 2-furanyl CH.sub.3CH.sub.2CH.sub.2CH.s-
ub.2O-- isopropyloxy OH H --OCH.sub.2OP(O)(OH).sub.2
--OCO.sub.2CH.sub.3 Ph 2-furanyl CH.sub.3CH.sub.2CH.sub.2CH.su-
b.2O-- isopropyloxy --OCO.sub.2CH.sub.2CH.sub.3 H
--OCH.sub.2OP(O)(OH).sub.2 OMe Ph 2-furanyl
CH.sub.3CH.sub.2CH.sub.2CH.sub.2O-- isopropyloxy OH H
--OCH.sub.2OP(O)(OH).sub.2 OMe Ph 2-furanyl
CH.sub.3CH.sub.2CH.sub.2CH.sub.2O-- isopropyloxy
--OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OP(O)(OH).sub.2 --OC(O)Ph
Ph 2-furanyl CH.sub.3CH.sub.2CH.sub.2CH.sub.2O-- isopropyloxy OH H
--OCH.sub.2OP(O)(OH).sub.2 --OC(O)Ph Ph 2-furanyl
CH.sub.3CH.sub.2CH.sub.2CH.sub.2O-- isopropyloxy
--OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OCH.sub.2OP(- O)(OH).sub.2
--OCO.sub.2CH.sub.3 (CH.sub.3).sub.3CO-- 2-furanyl isopropyloxy
CH.sub.3CH.sub.2CH.sub.2CH.sub.2O-- OH H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 --OCO.sub.2CH.sub.3
(CH.sub.3).sub.3CO-- 2-furanyl isopropyloxy
CH.sub.3CH.sub.2CH.sub.2CH.sub.2O-- --OCO.sub.2CH.sub.2CH.sub.3 H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 OMe (CH.sub.3).sub.3CO--
2-furanyl isopropyloxy CH.sub.3CH.sub.2CH.sub.2CH.sub.2O-- OH H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 OMe (CH.sub.3).sub.3CO--
2-furanyl isopropyloxy CH.sub.3CH.sub.2CH.sub.2CH.s- ub.2O--
--OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OCH.sub.2OP(O)(OH)- .sub.2
--OC(O)Ph (CH.sub.3).sub.3CO-- 2-furanyl isopropyloxy
CH.sub.3CH.sub.2CH.sub.2CH.sub.2O-- OH H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 --OC(O)Ph (CH.sub.3).sub.3CO--
2-furanyl isopropyloxy CH.sub.3CH.sub.2CH.sub.2CH.s- ub.2O--
--OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OCH.sub.2OP(O)(OH)- .sub.2
--OCO.sub.2CH.sub.3 (CH.sub.3).sub.3CO-- isobutenyl
--OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OCH.sub.2OP(O)(OH).sub.2
OMe (CH.sub.3).sub.3CO-- isobutenyl --OCO.sub.2CH.sub.2CH.sub.3 H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 --OC(O)Ph (CH.sub.3).sub.3CO--
isobutenyl OH H --OCH.sub.2OCH.sub.2OP(O)(OH).sub.2
--OCO.sub.2CH.sub.3 Ph 2-furanyl OH H --OCH.sub.2OCH.sub.2OP(O)(OH-
).sub.2 OMe Ph 2-furanyl OH H --OCH.sub.2OCH.sub.2OP(O)(OH).sub.2
--OC(O)Ph Ph 2-furanyl --OCO.sub.2CH.sub.2CH.sub.3 H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 --OCO.sub.2CH.sub.3
(CH.sub.3).sub.3CO-- 2-propenyl --OCO.sub.2CH.sub.2CH.sub.3 H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 OMe (CH.sub.3).sub.3CO--
2-propenyl --OCO.sub.2CH.sub.2CH.sub.3 H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 --OC(O)Ph (CH.sub.3).sub.3CO--
2-propenyl --OCH.sub.2OCH.sub.2OP(O- )(OH).sub.2 H OH AcO
(CH.sub.3).sub.3CO-- 2-furanyl 2-thienyl 3-furanyl 3-thienyl
isobutenyl 2-propenyl cyclopropyl --OCH.sub.2OCH.sub.2OP(O)(-
OH).sub.2 H OH AcO CH.sub.3CH.sub.2CH.sub.2CH.sub.2O-- 2-furanyl
isopropyloxy (CH.sub.3).sub.3CO--
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 H OH --OCO.sub.2CH.sub.3
(CH.sub.3).sub.3CO-- 2-furanyl Ph isopropyloxy
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 H OH OMe (CH.sub.3).sub.3CO--
2-furanyl Ph isopropyloxy --OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 H OH
--OC(O)Ph (CH.sub.3).sub.3CO-- 2-furanyl Ph isopropyloxy
--OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OCH.sub.2OP(O)(OH).sub.2
AcO Ph Ph OH F H --OCH.sub.2OP(O)(OH).sub.2 (CH.sub.3).sub.3CO-- Ph
Ph --OCO.sub.2CH.sub.2CH.sub.3 F H --OCH.sub.2OP(O)(OH).sub.2
(CH.sub.3).sub.3CO-- Ph Ph --OCH.sub.2OP(O)(OH).sub.2 F H AcO Ph
2-furanyl isobutenyl 3-furanyl 2-thienyl 2-propenyl cyclopropyl
3-thienyl isopropyl --OCH.sub.2OCH.sub.2OP(O)(OH).sub.- 2 F H AcO
Ph 2-furanyl isobutenyl 3-furanyl 2-thienyl 2-propenyl cyclopropyl
3-thienyl isopropyl --OCH.sub.2OP(O)(OH).sub.2 F H AcO
(CH.sub.3).sub.3CO-- 2-furanyl 3-thienyl isobutenyl 3-furanyl
cyclopropyl 2-thienyl Ph 2-propenyl
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 F H AcO (CH.sub.3).sub.3CO--
2-furanyl 3-thienyl isobutenyl 3-furanyl cyclopropy 2-thienyl Ph
2-propenyl --OCH.sub.2OP(O)(OH).sub.2 F H --OCO.sub.2CH.sub.3
(CH.sub.3).sub.3CO-- 2-furanyl --OCH.sub.2OP(O)(OH).sub.2 F H OMe
(CH.sub.3).sub.3CO-- 2-furanyl --OCH.sub.2OP(O)(OH).sub.2 F H
--OC(O)Ph (CH.sub.3).sub.3CO-- 2-furanyl
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 F H --OCO.sub.2CH.sub.3
(CH.sub.3).sub.3CO-- 2-furanyl --OCH.sub.2OCH.sub.2OP(O)(OH).sub.2
F H OMe (CH.sub.3).sub.3CO-- 2-furanyl --OCH.sub.2OCH.sub.2OP(O)(O-
H).sub.2 F H --OC(O)Ph (CH.sub.3).sub.3CO-- 2-furanyl
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 H OH OH (CH.sub.3).sub.3CO-- Ph
OH H --OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 OH (CH.sub.3).sub.3CO-- Ph
--OCO.sub.2CH.sub.2CH.sub.3 H --OCH.sub.2OCH.sub.2OP(O)(OH).sub.2
OH (CH.sub.3).sub.3CO-- Ph OH H OH
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.- 2 (CH.sub.3).sub.3CO-- Ph
--OCO.sub.2CH.sub.2CH.sub.3 H OH
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 (CH.sub.3).sub.3CO-- Ph OH F H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 (CH.sub.3).sub.3CO-- Ph
2-furanyl 3-furanyl 2-thienyl 3-thienyl isobutenyl cyclopropyl
2-propenyl --OCO.sub.2CH.sub.2CH.sub.3 F H --OCH.sub.2OCH.sub.2OP(-
O)(OH).sub.2 (CH.sub.3).sub.3CO-- Ph 2-furanyl 3-furanyl 2-thienyl
3-thienyl isobutenyl cyclopropyl 2-propenyl
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 OAc Ph Ph 2-furanyl
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.- 2 H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 OAc tBuO Ph 2-furanyl
--OCH.sub.2(OCH.sub.2).sub.2OP(O)(OH).sub.2 H OH OAc Ph Ph
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 --OCH.sub.2OP(O)(OH).sub.2
--OCH.sub.2(OCH.sub.2).sub.2OP(O)(OH).sub.2
--OCH.sub.2(OCH.sub.2).sub.2OP(O)(OH).sub.2 H OH OAc tBuO Ph
2-furanyl --OCH.sub.2(OCH.sub.2).sub.2OP(O)(OH).sub.2 H
--OCH.sub.2OP(O)(OH).sub.2 OAc tBuO Ph 2-furanyl
--OCH.sub.2(OCH.sub.2).sub.2OP(O)(OH).sub.2 H
--OCH.sub.2OCH.sub.2OP(O)(O- H).sub.2 OAc tBuO Ph 2-furanyl
--OCH.sub.2(OCH.sub.2).s- ub.2OP(O)(OH).sub.2 H
--OCH.sub.2(OCH.sub.2).sub.2OP(O)(OH).sub.2 OAc tBuO Ph 2-furanyl
--OCH.sub.2(OCH.sub.2).sub.3OP(O)(OH).sub- .2 H --OH OAc Ph Ph
--OCH.sub.2(OCH.sub.2).sub.3OP(O)(OH).sub.2 H --OH OAc tBuO Ph
2-furanyl --OCH.sub.2(OCH.sub.2).sub.- 3OP(O)(OH).sub.2 H
--OCH.sub.2OP(O)(OH).sub.2 OAc Ph Ph tBuO
--OCH.sub.2(OCH.sub.2).sub.3OP(O)(OH).sub.2 H
--OCH.sub.2OP(O)(OH).su- b.2 OAc tBuO 2-furanyl
--OCH.sub.2(OCH.sub.2).sub.3OP(O)(OH).sub.2 H
--OCH.sub.2OCH.sub.2OP(O)(OH).sub.2 OAc Ph Ph tBuO
--OCH.sub.2(OCH.sub.2).sub.3OP(O)(OH).sub.2 H
--OCH.sub.2(OCH.sub.2).sub.- 2OP(O)(OH).sub.2 OAc tBuO 2-furanyl
--OCH.sub.2(OCH.sub.2).sub.3OP(- O)(OH).sub.2 H
--OCH.sub.2(OCH.sub.2).sub.2OP(O)(OH).sub.2 OAc Ph Ph tBuO
--OCH.sub.2(OCH.sub.2).sub.3OP(O)(OH).sub.2 H
--OCH.sub.2(OCH.sub.2).sub.2OP(O)(OH).sub.2 OAc tBuO 2-furanyl
--OCH.sub.2(OCH.sub.2).sub.3OP(O)(OH).sub.2 H
--OCH.sub.2(OCH.sub.2).sub.- 3OP(O)(OH).sub.2 OAc Ph Ph 2-furanyl
--OCH.sub.2(OCH.sub.2).sub.3OP(O)(OH).sub.2 H
--OCH.sub.2(OCH.sub.2).sub.-
3OP(O)(OH).sub.2 OAc tBuO Ph 2-furanyl *"c"]indicates cyclo
* * * * *