U.S. patent application number 11/502602 was filed with the patent office on 2007-02-15 for substituted-1, 3-oxathiolanes and substituted-1, 3-dioxolanes with antiviral properties.
Invention is credited to Bernard Belleau, Pierette Belleau, Dilip M. Dixit, Nghe Nguyen-Ba.
Application Number | 20070037977 11/502602 |
Document ID | / |
Family ID | 37116131 |
Filed Date | 2007-02-15 |
United States Patent
Application |
20070037977 |
Kind Code |
A1 |
Belleau; Bernard ; et
al. |
February 15, 2007 |
Substituted-1, 3-oxathiolanes and substituted-1, 3-dioxolanes with
antiviral properties
Abstract
Disclosed are compounds of the formula ##STR1## wherein R.sub.1
is hydrogen or an acyl group having 1 to 16 carbon atoms; R.sub.2
is a purine or pyrimidine base or an analogue or derivative
thereof; Z is O, S, S.dbd.O or SO.sub.2; and pharmaceutically
acceptable derivatives thereof. Also, described are process for and
intermediates of use in their preparation, pharmaceutical
compositions containing these compounds, and the use of these
compounds in the antiviral treatment of mammals.
Inventors: |
Belleau; Bernard; (Montreal,
CA) ; Belleau; Pierette; (Montreal, CA) ;
Dixit; Dilip M.; (Roxboro, CA) ; Nguyen-Ba; Nghe;
(La Prairie, CA) |
Correspondence
Address: |
MILLEN, WHITE, ZELANO & BRANIGAN, P.C.
2200 CLARENDON BLVD.
SUITE 1400
ARLINGTON
VA
22201
US
|
Family ID: |
37116131 |
Appl. No.: |
11/502602 |
Filed: |
August 11, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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08468362 |
Jun 6, 1995 |
7119202 |
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11502602 |
Aug 11, 2006 |
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08306830 |
Sep 15, 1994 |
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08468362 |
Jun 6, 1995 |
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07564160 |
Aug 7, 1990 |
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08306830 |
Sep 15, 1994 |
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07308101 |
Feb 8, 1989 |
5047407 |
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07564160 |
Aug 7, 1990 |
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Current U.S.
Class: |
544/269 ;
544/276; 544/277; 544/280; 544/310; 544/314 |
Current CPC
Class: |
C07D 411/14 20130101;
C07D 473/40 20130101; C07D 411/04 20130101; C07D 405/04 20130101;
C07D 327/04 20130101; C07D 473/00 20130101 |
Class at
Publication: |
544/269 ;
544/277; 544/310; 544/314; 544/280; 544/276 |
International
Class: |
C07D 473/02 20070101
C07D473/02; C07D 487/02 20070101 C07D487/02; C07D 411/02 20070101
C07D411/02 |
Claims
1-22. (canceled)
23. A process for preparing an oxathiolane of formula (Ia), the
geometric and optical isomers thereof, and mixtures of those
isomers: ##STR78## wherein: R.sub.1 is selected from a group
consisting of hydrogen, an acyl group having from 1 to 16 carbon
atoms, and a hydroxyl protecting group; R.sub.2 is a purine or
pyrimidine base or an analogue or derivative thereof; Z is selected
from a group consisting of S, S.dbd.O, and SO.sub.2; the process
comprising the steps of: a) reacting a compound having the formula
HSCH.sub.2CH(OR.sub.x).sub.2, wherein R.sub.x is substituted or
unsubstituted C.sub.1-6 alkyl, with a compound having formula
R.sub.yCO--OCH.sub.2CHO, wherein R.sub.y is substituted or
unsubstituted C.sub.1-6 alkyl or substituted or unsubstituted aryl,
in an inert solvent containing an acid catalyst to produce an
intermediate having a formula: ##STR79## b) reacting the
intermediate with a silylated pyrimidine or purine base or an
analogue thereof, in the presence of a Lewis acid to produce a
compound of the formula: ##STR80## c) optionally treating the
resulting compound with an oxidizing agent in a suitable solvent to
produce the corresponding sulfoxides of formula (Ia), wherein Z is
S.dbd.O or SO.sub.2.
24.-27. (canceled)
28. A process for preparing a dioxolane of formula (Ib), the
geometric and optical isomers thereof, and mixtures of those
isomers, ##STR81## wherein: R.sub.1 is selected from a group
consisting of hydrogen, an acyl group having from 1 to 16 carbon
atoms, and a hydroxyl protecting group; and R.sub.2 is a purine or
pyrimidine base or an analogue or derivative thereof; the process
comprising the steps of: a) condensing a compound having a formula
R.sub.zCH.sub.2CH(OR.sub.x), wherein R.sub.z is a halo selected
from bromo, chloro, fluoro or iodo and R.sub.x is substituted or
unsubstituted C.sub.1-6 alkyl, with glycerol in an inert solvent
containing an acid catalyst to produce an intermediate having a
formula ##STR82## b) oxidizing the hydroxymethyl group of the
intermediate with an oxidizing agent to the acid and further
oxidizing with an organic peracid to produce a compound of the
following formula ##STR83## wherein R.sub.y is substituted or
unsubstituted C.sub.1-6 alkyl or substituted or unsubstituted aryl;
c) treating the intermediate with a silylated pyrimidine or purine
base or an analogue thereof, in the presence of a Lewis acid to
produce a compound of the following formula ##STR84## d) displacing
the R.sub.z group with a salt of an acid.
29.-35. (canceled)
36. Intermediates useful for the production of oxathiolane and
dioxolane compounds selected from the group consisting of: cis- and
trans-2-chloromethyl-4-(m-chloro-benzoyloxy)-1,3-dioxolane; cis-
and trans-2-benzoyloxymethyl-1,3-dioxolane-4-carboxyllic acid; and
cis- and trans-2-benzoyloxymethyl-4-(m-chlorobenzoyloxy)-1,
e-dioxolane.
37. (canceled)
Description
[0001] The present invention relates to novel substituted
1,3-oxathiolane and substituted-1,3-dioxolane cyclic compounds
having pharmacological activity, to processes for and intermediates
of use in their preparation, to pharmaceutical compositions
containing them, and to the use of these compounds in the antiviral
treatment of mammals.
[0002] Retroviral infections are a serious cause of disease, most
notably, the acquired immunodeficiency syndrome (AIDS). The human
immunodeficiency virus (HIV) has-been recognized as the etiologic
agent of AIDS, and compounds having an inhibitory effect against
HIV multiplication have been actively sought.
[0003] Mitsuya et al., "3'-Azido-3'-deoxythymidine (BW A509U): An
antiviral agent that inhibits the infectivity and cytopathic effect
of human T-lymphotropic virus type III/lymphadenopathy-associated
virus in vitro", Proc. Natl. Acad. Sci. U.S.A., 82, pp. 7096-7100
(1985), refers to a compound of formula (A)
(3'-azido-2',3'-dideoxythymidine), commonly referred to as AZT.
This compound is said to be useful in providing some protection for
AIDS carriers against the cytopathogenic effect of immunodeficiency
virus (HIV). ##STR2##
[0004] Mitsuya et al., "Inhibition of the in vitro infectivity and
cytopathic effect of human T-lymphotrophic virus type
III/lymphadenopathy-associated virus (HTLV-III/LAV) by
2'3'-dideoxynucleosides", Proc. Natl. Acad. Sci. U.S.A., 86, pp.
1911-15 (1986), have also referred to a group of
2',3'-dideoxynucleosides shown in formula (B) which are said to
possess protective activity against HIV-induced cytopathogenicity.
##STR3##
[0005] Balzarini et al., "Potent and selective anti-HTLV-III/LAV
activity of 2',3'-dideoxycytidinene, the 2',3'-unsaturated
derivative of 2',3'-dideoxycytidine", Biochem. Biophys. Res. Comm.,
140, pp. 735-42 (1986), refer to an unsaturated analogue of these
nucleosides--2',3'-dideoxycytidine, shown in formula (C)--as being
characterized by antiretroviral activity. ##STR4##
[0006] Baba et al., "Both 2',3'-dideoxythymidine and its
2',3'-unsaturated derivative (2',3'-dideoxythymidinene) are potent
and selective inhibitors of human immunodeficiency virus
replication in vitro", Biochem. Biophys. Res. Comm., 142, pp.
128-34 (1987), refer to the 2',3'-unsaturated analogue shown in
formula (D) of 2',3'-dideoxythymidine. This analogue is purported
to be a potent selective inhibitor of HIV replication. ##STR5##
[0007] Analogues of AZT known as 3'-azido-2',3'-dideoxyuridine
shown in formula (E), where Y is bromine or iodine, have been said
to have an inhibitory activity against Moloney murine leukemia in
T. S. Lin et al., "Synthesis and antiviral activity of various
3'-azido, 3'amino, 2',3'-unsaturated and 2',3'-dideoxy analogues of
pyrimidine, deoxyribonucleosides against retroviruses", J. Med.
Chem., 30, pp. 440-41 (1987). ##STR6##
[0008] Finally, the 3'-fluoro analogues of 2',3'-dideoxycytidine
shown in formula (F) and of 2',3'-dideoxythymidine shown in formula
(G) are referred to in Herdewijn et al., "3'-Substituted
2',3'-dideoxynucleoside analogues as potential
anti-HIV(HTLV-III/LAV) agents", J. Med. Chem., 30, pp. 1270-78
(1987), as having potent antiretroviral activity. ##STR7##
[0009] The most potent anti-HIV compounds thus far reported are
2',3'-dideoxynucleosides, more particularly, 2',3'-dideoxy cytidine
(ddCyd) and 3'-azido-2',3'-dideoxythymidine (AzddThd or AZT). These
compounds are also active against other kinds of retroviruses such
as the Moloney murine leukemia virus. Because of the increasing
incidence and the life-threatening characteristics of AIDS, efforts
are being expended to discover and develop new non-toxic and potent
inhibitors of HIV and blockers of its infectivity. It is therefore
an object of the present invention to provide effective anti-HIV
compounds of low toxicity and a synthesis of such new compounds
that is readily feasible.
[0010] A structurally distinct class of compounds known as
2-substituted-5-substituted-1,3-oxathiolanes and
2-substituted-4-substituted-1,3-dioxolanes has now been discovered
and found to have antiretroviral activity. In particular, these
compounds have been found to act as non-toxic inhibitors of the
replication of HIV-1 in T-lymphocytes over prolonged periods of
time.
[0011] There are accordingly provided in a first aspect of this
invention compounds of formula (I) ##STR8## wherein R.sub.1 is
hydrogen or an acyl radical from 1 to 16 carbon atoms, preferably a
benzoyl or a benzoyl substituted in any position by at least one
halogen (bromine, chlorine, fluorine or iodine), C.sub.1-6 alkyl,
C.sub.1-6 alkoxy, nitro or trifluoromethyl groups;
[0012] R.sub.2 is a purine or pyrimidine base or an analogue or
derivative thereof;
[0013] Z is O, S, S.dbd.O or SO.sub.2; and
[0014] pharmaceutically acceptable derivatives thereof.
[0015] It will be appreciated by those skilled in the art that the
compounds of formula (I) contain at least two chiral centers (shown
as * in formula (I)) and thus exist in the form of two pairs of
optical isomers (i.e., enantiomers) and mixtures thereof including
racemic mixtures. Thus the compounds of formula (I) may be either
cis isomers, as represented by formula (II), or trans isomers, as
represented by formula (III), or mixtures thereof. Each of the cis
and trans isomers can exist as one of two enantiomers or as
mixtures thereof including racemic mixtures. All such isomers and
mixtures thereof including racemic mixtures are included within the
scope of the invention. ##STR9##
[0016] The compounds of formula (I) are preferably in the form of
their cis isomers.
[0017] It will also be appreciated that when Z is S.dbd.O the
compounds exist in two additional isomeric forms as shown in
formulas (IIa) and (IIb) which differ in the configuration of the
oxide oxygen atom relative to the 2,5-substituents. The compounds
of the invention additionally embrace such isomers and mixtures
thereof. ##STR10##
[0018] The purine or pyrimidine base or analogue or derivative
thereof R.sub.2 will be linked at the 9- or 1-position,
respectively.
[0019] By "purine or pyrimidine base" or an analogue or derivative
thereof is meant a purine or pyrimidine base found in native
nucleosides or an analogue thereof which mimics such bases in that
their structures (the kinds of atoms and their arrangement) are
similar to the native bases but may either possess additional or
lack certain of the functional properties of the native bases. Such
analogues include those derived by replacement of a CH.sub.2 moiety
by a nitrogen atom (for example, 5-azapyrimidines such as
5-azacytosine) or vice verse (for example 7-deazapurines, for
example 7-deazadenosine or 7-deazaguanosine) or both (e.g.,
7-deaza-8-azapurines). By derivatives of such bases or analogues
are meant those compounds wherein ring substituents are either
incorporated, removed or modified by conventional substituents
known in the art, e.g., halogen, hydroxyl, amino, C.sub.1-6 alkyl.
Such purine or pyrimidine bases, analogues and derivatives will be
well known to those skilled in the art.
[0020] Conveniently the group R.sub.2 is selected from: ##STR11##
##STR12## wherein R.sub.3 is selected from the group of hydrogen,
acetyl, hydroxyl or C.sub.1-6 alkyl or alkenyl groups;
[0021] R.sub.4 and R.sub.5 are independently selected from the
group of hydrogen, hydroxymethyl, trifluoromethyl, substituted or
unsubstituted C.sub.1-6 alkyl or alkenyl groups, bromine, chlorine,
fluorine, or iodine;
[0022] R.sub.6 is selected from the group of hydrogen, cyano,
carboxy, ethoxycarbonyl, carbamoyl, or thiocarbamoyl; and
[0023] X and Y are independently selected from the group of
hydrogen, bromine, chlorine, fluorine, iodine, amino or hydroxy
groups.
[0024] Preferably R.sub.2 is ##STR13## wherein R.sub.3 and R.sub.4
are as defined hereinabove.
[0025] Z is preferably --S--.
[0026] When the compound of formula (I) is a 1,3-oxathiolane of
formula (Ia), where Z is S, S.dbd.O or SO.sub.2, ##STR14##
preferably:
[0027] R.sub.1 is selected from a group consisting of hydrogen and
an acyl group having 1 to 16 carbon atoms;
[0028] R.sub.2 is a heterocyclic radical selected from the group
consisting of: ##STR15##
[0029] R.sub.3 and R.sub.4 are independently selected from the
group consisting of hydrogen and C.sub.1-6 alkyl groups;
[0030] R.sub.5 is selected from the group consisting of hydrogen,
C.sub.1-6 alkyl, bromine, chlorine, fluorine, and iodine; and
[0031] X and Y are independently selected from the group consisting
of bromine, chlorine, fluorine, iodine, amino and hydroxyl
groups.
[0032] When the compound of formula (I) is a 1,3-dioxolane of
formula (Ib), ##STR16## preferably:
[0033] R.sub.1 is selected from the group consisting of hydrogen,
an aliphatic acyl group having 1 to 16 carbon atoms, benzoyl and
benzoyl substituted in any position by a halogen, a lower alkyl, a
lower alkoxy, a nitro or a trifluoromethyl group;
[0034] R.sub.2 is a heterocyclic radical selected from the group
consisting of: ##STR17## wherein:
[0035] R.sub.3 is selected from the group consisting of hydrogen
and lower alkyl radicals having from 1 to 3 carbon atoms;
[0036] R.sub.4 is selected from the group consisting of hydrogen,
lower alkyl and alkenyl radicals having from 1 to 3 carbon atoms;
and
[0037] R.sub.5 is selected from the group consisting of lower alkyl
and alkenyl radicals having from 1-3 carbon atoms, fluoro and
iodo.
[0038] By "a pharmaceutically acceptable derivative" is meant any
pharmaceutically acceptable salt, ester, or salt of such ester, of
a compound of formula (I) or any
other compound which, upon administration to the recipient, is
capable of providing (directly or indirectly) a compound of formula
(I) or an antivirally active metabolite or residue thereof.
[0039] It will be appreciated by those skilled in the art that the
compounds of formula (I) may be modified to provide
pharmaceutically acceptable derivatives thereof,
at functional groups in both the base moiety, R.sub.2, and at
the hydroxymethyl group of the oxathiolane or dioxolane ring.
Modification at all such functional groups is included within the
scope of the invention. However, of
particular interest are pharmaceutically acceptable derivatives
(e.g., esters) obtained by modification of the 2-hydroxymethyl
group of the oxathiolane or dioxolane ring.
[0040] Preferred esters of the compounds of formula (I) include the
compounds in which R.sub.1 is replaced by a carboxyl function
##STR18## in which the non-carbonyl moiety R of the ester grouping
is selected from hydrogen, straight or branched chain alkyl (e.g.,
methyl, ethyl, n-propyl, t-butyl, n-butyl), alkoxyalkyl (e.g.,
methoxymethyl), aralkyl (e.g., benzyl), aryloxyalkyl (e.g.,
phenoxymethyl), aryl (e.g., phenyl optionally substituted by
halogen, C.sub.1-4 alkyl or C.sub.1-4 alkoxy); substituted dihydro
pyridinyl (e.g., N-methyldihyrdro pyridinyl); sulphonate esters
such as alkyl- or aralkylsulphonyl (e.g., methanesulphonyl);
sulfate esters; amino acid esters (e.g., L-valyl or L-isoleucyl)
and mono-, di- or tri-phosphate esters.
[0041] Also included within the scope of such esters are esters
derived from polyfunctional acids such as carboxylic acids
containing more than one carboxyl group, for example, dicarboxylic
acids HO.sub.2C(CH.sub.2).sub.nCO.sub.2H where n is an integer of 1
to 10 (for example, succinic acid) or phosphoric acids. Methods for
preparing such esters are well known. See, for example, Hahn et
al., "Nucleotide Dimers as Anti-Human Immunodeficiency Virus
Agents", Nucleotide Analogues, pp. 156-159 (1989) and Busso et al.,
"Nucleotide Dimers Suppress HIV Expression In Vitro", AIDS Research
and Human Retroviruses, 4(6), pp. 449-455 (1988). Where esters are
derived from such acids, each acidic group is preferably esterified
by a compound of formula (I) or other nucleosides or analogues and
derivatives thereof to provide esters of the formula (IV) where:
##STR19## W is ##STR20## and n is an integer of 1 to 10 or
##STR21## J is any nucleoside or nucleoside analog or derivative
thereof and Z and R.sub.2 are as defined above. Among the preferred
nucleosides and nucleoside analogues are
3'-azido-2',3'-dideoxythymidine, 2',3'-dideoxycytidine,
2',3'-dideoxyadenosine, 2',3'-dideoxyinosine,
2',3'-dideoxythymidine, 2',3'-dideoxy-2',3'-didehydrothymidine, and
2',3'-dideoxy-2',3'-didehydrocytidine and ribavirin and those
nucleosides whose bases are depicted on pages 7-8 of this
specification. We most prefer a homodimer consisting of two
nucleosides of formula (I).
[0042] With regard to the above described esters, unless otherwise
specified, any alkyl moiety present advantageously contains 1 to 16
carbon atoms, preferably 1 to 4 carbon atoms and could contain one
or more double bonds. Any aryl moiety present in such esters
advantageously comprises a phenyl group.
[0043] In particular the esters may be a C.sub.1-16 alkyl ester, an
unsubstituted benzoyl ester or a benzoyl ester substituted by at
least one halogen (bromine, chlorine, fluorine or iodine),
C.sub.1-6 alkylor alkenyl, saturated or unsaturated C.sub.1-6
alkoxy, nitro or trifluoromethyl groups.
[0044] Pharmaceutically acceptable salts of the compounds of
formula (I) include those derived from pharmaceutically acceptable
inorganic and organic acids and bases. Examples of suitable acids
include hydrochloric, hydrobromic, sulfuric, nitric, perchloric,
fumaric, maleic, phosphoric, glycollic, lactic, salicylic,
succinic, toluene-p-sulfonic, tartaric, acetic, citric,
methanesulfonic, formic, benzoic, malonic, naphthalene-2-sulfonic
and benzenesulfonic acids. Other acids such as oxalic, while not in
themselves pharmaceutically acceptable, may be useful in the
preparation of salts useful as intermediates in obtaining the
compounds of the invention and their pharmaceutically acceptable
acid addition salts.
[0045] Salts derived from appropriate bases include alkali metal
(e.g., sodium), alkaline earth metal (e.g., magnesium), ammonium
and NR.sub.4+ (where R is C.sub.1-4 alkyl) salts.
[0046] References hereinafter to a compound according to the
invention include both compounds of formula (I) and their
pharmaceutically acceptable derivatives.
[0047] Specific compounds of formula (I) include: [0048]
Cis-2-hydroxymethyl-5-(cytosin-1'-yl)-1,3-oxathiolane,
trans-2-hydroxymethyl-5-(cytosin-1'-yl)-1,3-oxathiolane, and
mixtures thereof; [0049]
Cis-2-benzoyloxymethyl-5-(cytosin-1'-yl)-1,3-oxathiolane,
trans-2-benzoyloxymethyl-5-(cytosin-1'-1,3-oxathiolane, and
mixtures thereof; [0050]
cis-2-hydroxymethyl-5-(N.sub.4'-acetyl-cytosin-1'-yl)-1,3-oxathiolane,
trans-2-hydroxymethyl-5-(N.sub.4'-acetyl-cytosin-1'-yl)-1,3-oxathiolane,
and mixtures thereof; [0051]
Cis-2-benzoyloxymethyl-5-(N.sub.4'-acetyl-cytosin-1'-yl)-1,3-oxathiolane,
trans-2-benzoyloxymethyl-5-(N.sub.4'-acetyl-cytosin-1'-yl)-1,3-oxathiolan-
e, and mixtures thereof; and [0052]
Cis-2-hydroxymethyl-5-(cytosin-1'-yl)-3-oxo-1,3-oxathiolane; [0053]
Cis-2-hydroxymethyl-5-(N-dimethylamino-methylene
cytosin-1'-yl)-1,3-oxathiolane; [0054]
Bis-Cis-2-succinyloxymethyl-5-(cytosin-1'-yl)-1,3-oxathiolane;
[0055]
Cis-2-benzoyloxymethyl-5-(6'-chloropurin-N-9'-yl)-1,3-oxathiolane;
trans-2-benzoyloxymethyl-5-(6'-chloropurin-N-9'-yl)-1,3-oxathiolane,
and mixtures thereof; [0056]
Cis-2-hydroxymethyl-5-(6'-hydroxypurin-N-9'-yl)-1,3-oxathiolane;
trans-2-hydroxymethyl-5-(6'-hydroxypurin-N-9'-yl)-1,3-oxathiolane;
and mixtures thereof [0057]
Cis-2-benzoyloxymethyl-5-(uracil-N-1'-yl)-1,3-oxathiolane,
trans-2-benzoyloxymethyl-5-(uracil-N-1'-yl)-1,3-oxathiolane, and
mixtures thereof; [0058]
Cis-2-hydroxymethyl-5-(uracil-N-1'-yl)-1,3-oxathiolane; [0059]
Cis-2-benzoyloxymethyl-5-(thymin-N-1'-yl)-1,3-oxathiolane,
trans-2-benzoyloxymethyl-5-(thymin-N-1'-yl)-1,3-oxathiolane, and
mixtures thereof; [0060]
Cis-2-hydroxymethyl-5-(thymin-N-1'-yl)-1,3-oxathiolane; [0061]
Cis-2-hydroxymethyl-5-(adenin-9'-yl)-1,3-oxathiolane,
trans-2-hydroxymethyl-5-(adenin-9'-yl)-1,3-oxathiolane, and
mixtures thereof; [0062]
Cis-2-hydroxymethyl-5-(inosin-9'-yl)-1,3-oxathiolane,
trans-2-hydroxymethyl-5-(inosin-9'-yl)-1,3-oxathiolane, and
mixtures thereof; [0063]
Cis-2-benzoyloxymethyl-5-(N.sub.4'-acetyl-5'-fluorocytosin-1'-yl)-1,3-oxa-
thiolane,
trans-2-benzoyloxymethyl-5-(N.sub.4'-acetyl-5'-fluorocytosin-1'--
yl)-1,3-oxathiolane, and mixtures thereof; [0064]
Cis-2-hydroxymethyl-5-(5'-fluorocytosin-1'-yl)-1,3-oxathiolane,
trans-2-hydroxymethyl-5-(5'-fluorocytosin-1'-yl)-1,3-oxathiolane,
and mixtures thereof; [0065]
Cis-2-acetoxymethyl-4-(thymin-1'-yl)-1,3-dioxolane,
trans-2-acetoxymethyl-4-(thymin-1'-yl)-1,3-dioxolane, and mixtures
thereof; [0066] Cis-2-hydroxylethyl-4-(thymin-1'-yl)-1,3'
dioxolane, trans-2-hydroxymethyl-4-(thymin-1'-yl)-1,3-dioxolane,
and mixtures thereof; [0067]
Cis-2-benzoyloxymethyl-4-(cytosin-1-yl)-1,3dioxolane,
trans-2-benzoyloxymethyl-4-(cytosin-1'-yl)-1,3dioxolane, and
mixtures thereof; [0068]
Cis-2-hydroxymethyl-4-(cytosin-1'-yl)-1,3-dioxolane,
trans-2-hydromethyl-4-(cytosin-1'-yl)-1,3-dioxolane, and mixtures
thereof; [0069]
Cis-2-benzoyloxymethyl-4-(adenin-9'-yl)-1,3-dioxolane,
trans-2-benzoyloxymethyl-4-(adenin-9'-yl)-1,3-dioxolane, and
mixtures thereof; [0070]
Cis-2-hydroxymethyl-4-(adenin-9'-yl)-1,3-dioxolane,
trans-2-hydroxymethyl-4-(adenin-9'-yl)-1,3-dioxolane, and mixtures
thereof; [0071]
Cis-2-benzoyloxylmethyl-4-(2'-amino-6'-chloro-purin-9'-yl)-1,3-dioxolane,
trans-2-benzoyloxylmethyl-4-(2'-amino-6'-chloro-purin-9'-yl)-1,3-dioxolan-
e, and mixtures thereof; [0072]
Cis-2-hydroxymethyl-4-(2'-amino-6'-chloro-purin-9'-yl)-1,3-dioxolane,
trans-2-hydroxymethyl-4-(2'-amino-6'-chloro-purin-9'-yl)-1,3-dioxolane,
and mixtures thereof; [0073]
Cis-2-hydroxymethyl-4-(2'-amino-purin-9'-yl)-1,3-dioxolane,
trans-2-hydroxymethyl-4-(2'-amino-purin-9'-yl)-1,3-dioxolane, and
mixtures thereof; [0074]
Cis-2-hydroxymethyl-4-(2',6'-diamino-purin-9'-yl)-1,3-dioxolane,
trans-2-hydroxymethyl-4-(2',6'-diamino-purin-9'-yl)-1,3-dioxolane,
and mixtures thereof; [0075]
Cis-2-hydroxymethyl-4-(guanin-9'-yl)-1,3-dioxolane,
trans-2-hydroxymethyl-4-(guanin-9'-yl)-1,3-dioxolane, and mixtures
thereof; [0076] Cis-2-hydroxymethyl-5-(N-dimethylamino methylene
cytosin-1'-yl)-1,3-dioxolane,
trans-2-hydroxymethyl-4-(N-dimethylamino methylene
cytosin-1'-yl)-1,3-dioxolane, and mixtures thereof; in the form of
a racemic mixture or a single enantiomer.
[0077] The compounds of the invention either themselves possess
antiviral activity and/or are metabolizable to such compounds. In
particular these compounds are effective in inhibiting the
replication of retroviruses, including human retroviruses such as
human immunodeficiency viruses (HIV's), the causative agents of
AIDS.
[0078] There is thus provided as a further aspect of the invention
a compound formula (I) or a pharmaceutically acceptable derivative
thereof for use as an active therapeutic agent in particular as an
antiviral agent, for example in the treatment of retroviral
infections.
[0079] In a further or alternative aspect there is provided a
method for the treatment of a viral infection, in particular an
infection caused by a retrovirus such as HIV, in a mammal,
including man, comprising administration of an effective amount of
an antiviral compound of formula (I) or a pharmaceutically
acceptable derivative thereof.
[0080] There is also provided in a further or alternative aspect of
this invention, use of a compound of formula (I) or a
pharmaceutically acceptable derivative thereof for the manufacture
of a medicament for the treatment of a viral infection.
[0081] The compounds of the invention are also useful in the
treatment of AIDS-related conditions such as AIDS-related complex
(ARC), persistent generalized lymphadenopathy (PGL), AIDS-related
neurological conditions (such as dementia), anti-HIV
antibody-positive and HIV-positive conditions, Kaposi's sarcoma,
thrombocytopenia purpurea and opportunistic infections.
[0082] The compounds of the invention are also useful in the
prevention or progression to clinical illness of individuals who
are anti-HIV antibody or HIV-antigen positive and in prophylaxis
following exposure to HIV.
[0083] The compounds of formula (I) or the pharmaceutically
acceptable derivatives thereof, may also be used for the prevention
of viral contamination of biological fluids such as blood or semen
in vitro.
[0084] Certain of the compounds of formula (I) are also useful as
intermediates in the preparation of other compounds of the
invention.
[0085] It will be appreciated by those skilled in the art that
references herein to treatment extends to prophylaxis as well as
the treatment of established infections or symptoms.
[0086] It will be further appreciated that the amount of a compound
of the invention required for use in treatment will vary not only
with the particular compound selected but also with the route of
administration, the nature of the condition being treated and the
age and condition of the patient and will be ultimately at the
discretion of the attendant physician or veterinarian. In general,
however, a suitable dose will be in the range from about 1 to about
750 mg/kg of body weight per day, such as 3 to about 120 mg per
kilogram body weight of the recipient per day, preferably in the
range of 6 to 90 mg/kg/day, most preferably in the range of 15 to
60 mg/kg/day.
[0087] The desired dose may conveniently be presented in a single
dose or as divided doses administered at appropriate intervals, for
example as two, three, four or more sub-doses per day.
[0088] The compound is conveniently administered in unit dosage
form; for example containing 10 to 1500 mg, conveniently 20 to 1000
mg, most conveniently 50 to 700 mg of active ingredient per unit
dosage form.
[0089] Ideally the active ingredient should be administered to
achieve peak plasma concentrations of the active compound of from
about 1 to 75 .mu.M, preferably about 2 to 50 .mu.M, most
preferably about 3 to about 30 .mu.M. This may be achieved, for
example, by the intravenous injection of a 0.1 to 5% solution of
the active ingredient, optionally in saline, or administered as a
bolus containing about 0.1 to about 110 mg/kg of the active
ingredient. Desirable blood levels may be maintained by a
continuous infusion to provide about 0.01 to about 5.0 mg/kg/hour
or by intermittent infusions containing about 0.4 to about 15 mg/kg
of the active ingredient.
[0090] While it is possible that, for use in therapy, a compound of
the invention may be administered as the raw chemical it is
preferable to present the active ingredient as a pharmaceutical
formulation.
[0091] The invention thus further provides a pharmaceutical
formulation comprising a compound of formula (I) or a
pharmaceutically acceptable derivative thereof together with one or
more pharmaceutically acceptable carriers thereof and, optionally,
other therapeutic and/or prophylactic ingredients. The carrier(s)
must be "acceptable" in the sense of being compatible with the
other ingredients of the formulation and not deleterious to the
recipient thereof.
[0092] Pharmaceutical formulations include those suitable for oral,
rectal, nasal, topical (including buccal and sub-lingual), vaginal
or parenteral (including intramuscular, sub-cutaneous and
intravenous) administration or in a form suitable for
administration by inhalation or insufflation. The formulations may,
where appropriate, be conveniently presented in discrete dosage
units and may be prepared by any of the methods well known in the
art of pharmacy. All methods include the step of bringing into
association the active compound with liquid carriers or finely
divided solid carriers or both and then, if necessary, shaping the
product into the desired formulation.
[0093] Pharmaceutical formulations suitable for oral administration
may conveniently be presented as discrete units such as capsules,
cachets or tablets each containing a predetermined amount of the
active ingredient; as a powder or granules; as a solution; as a
suspension; or as an emulsion. The active ingredient may also be
presented as a bolus, electuary or paste. Tablets and capsules for
oral administration may contain conventional excipients such as
binding agents, fillers, lubricants, disintegrants, or wetting
agents. The tablets may be coated according to methods well known
in the art. Oral liquid preparations may be in the form of, for
example, aqueous or oily suspensions, solutions, emulsions, syrups
or elixirs, or may be presented as a dry product for constitution
with water or other suitable vehicle before use. Such liquid
preparations may contain conventional additives such as suspending
agents, emulsifying agents, non-aqueous vehicles (which may include
edible oils) or preservatives.
[0094] The compounds according to the invention may also be
formulated for parenteral administration (e.g., by injection, for
example bolus injection or continuous infusion) and may be
presented in unit dose form in ampoules, pre-filled syringes, small
volume infusion or in multi-dose containers with an added
preservative. The compositions may take such forms as suspensions,
solutions, or emulsions in oily or aqueous vehicles, and may
contain formulatory agents such as suspending, stabilizing and/or
dispersing agents. Alternatively, the active ingredient may be in
powder form, obtained by aseptic isolation of sterile solid or by
lyophilization from solution, for constitution with a suitable
vehicle, e.g., sterile, pyrogen-free water, before use.
[0095] For topical administration to the epidermis, the compounds
according to the invention may be formulated as ointments, creams
or lotions, or as a transdermal patch. Ointments and creams may,
for example, be formulated with an aqueous or oily base with the
addition of suitable thickening and/or gelling agents. Lotions may
be formulated with an aqueous or oily base and will in general also
contain one or more emulsifying agents, stabilizing agents,
dispersing agents, suspending agents, thickening agents, or
coloring agents.
[0096] Formulations suitable for topical administration in the
mouth include lozenges comprising active ingredient in a flavored
based, usually sucrose and acacia or tragacanth; pastilles
comprising the active ingredient in an inert base such as gelatin
and glycerin or sucrose and acacia; and mouthwashes comprising the
active ingredient in a suitable liquid carrier.
[0097] Pharmaceutically formulations suitable for rectal
administration wherein the carrier is a solid, are most preferably
represented as unit dose suppositories. Suitable carriers include
cocoa butter and other materials commonly used in the art, and the
suppositories may be conveniently formed by admixture of the active
compound with the softened or melted carrier(s) followed by
chilling and shaping in molds.
[0098] Formulations suitable for vaginal administration may be
presented as pessaries, tampons, creams, gels, pastes, foams or
sprays containing in addition to the active ingredient, such
carriers as are known in the art to be appropriate.
[0099] For intra-nasal administration the compounds of the
invention may be used as a liquid spray or dispersible powder or in
the form of drops.
[0100] Drops may be formulated with an aqueous or non-aqueous base
also comprising one or more dispersing agents, solubilizing agents
or suspending agents. Liquid sprays are conveniently delivered from
pressurized packs.
[0101] For administration by inhalation, the compounds according to
the invention are conveniently delivered from an insufflator,
nebulizer or a pressurized pack or other convenient means of
delivering an aerosol spray. Pressurized packs may comprise a
suitable propellant such as dichlorodifluoromethane,
trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide
or other suitable gas. In the case of a pressurized aerosol, the
dosage unit may be determined by providing a valve to deliver a
metered amount.
[0102] Alternatively, for administration by inhalation or
insufflation, the compounds according to the invention may take the
form of a dry powder composition, for example a powder mix of the
compound and a suitable powder base such as lactose or starch. The
powder composition may be presented in unit dosage form in, for
example, capsules or cartridges or, e.g., gelatin or blister packs
from which the powder may be administered with the aid of an
inhalator or insufflator.
[0103] When desired, the above described formulations adapted to
give sustained release of the active ingredient, may be
employed.
[0104] The pharmaceutical compositions according to the invention
may also contain other active ingredients such as antimicrobial
agents, or preservatives.
[0105] The compounds of the invention may also be used in
combination with other therapeutic agents, for example, other
antiinfective agents. In particular the compounds of the invention
may be employed together with known antiviral agents.
[0106] The invention thus provides, in a further aspect, a
combination comprising a compound of formula (I) or a
physiologically acceptable derivative thereof together with another
therapeutically active agent, in particular, an antiviral
agent.
[0107] The combinations referred to above may conveniently be
presented for use in the form of a pharmaceutical formulation and
thus pharmaceutical formulations comprising a combination as
defined above together with a pharmaceutically acceptable carrier
thereof comprise a further aspect of the invention.
[0108] Suitable therapeutic agents for use in such combinations
include acyclic nucleosides such as acyclovir, ganciclovir,
interferons such as alpha-, beta- and gamma-interferon;
glucuronation inhibitors such as probenecid; nucleoside transport
inhibitors such as dipyridamole; nucleoside analogues such as
3'-azido-2',3'-dideoxythymidine, 2',3'-dideoxycytidine,
2',3'-dideoxyadenosine, 2',3'-dideoxyinosine,
2',3'-dideoxythymidine, 2',3'-dideoxy-2',3'-didehydrothymidine, and
2',3'-dideoxy-2',3'-didehydrocytidine and ribavirin;
immunomodulators such as interleukin II (IL2) and granulocyte
macrophage colony stimulating factor (GM-CSF), erythropoietin,
ampligen, thymomodulin, thymopentin, foscarnet, glycosylation
inhibitors such as 2-deoxy-D-glucose, castanospermine,
1-deoxynojirimycin; and inhibitors of HIV binding to CD4 receptors
such as soluble CD4, CD4 fragments and CD4-hybrid molecules.
[0109] The individual components of such combinations may be
administered either sequentially or simultaneously in separate or
combined pharmaceutical formulations.
[0110] When the compound of formula (I) or a pharmaceutically
acceptable derivative thereof is used in combination with a second
therapeutic agent active against the same virus, the dose of each
compound may be either the same or differ from that when the
compound is used alone. Appropriate doses will be readily
appreciated by those skilled in the art.
[0111] In the processes for preparing the compounds of this
invention, the following definitions are used:
[0112] R.sub.1 is a hydrogen, an acyl group having from 1 to 16
carbon atoms, or a hydroxyl protecting group;
[0113] R.sub.2 is a purine or pyrimidine base or an analogue or
derivative thereof;
[0114] R.sub.x is substituted or unsubstituted C.sub.1-6 alkyl;
[0115] R.sub.y is substituted or unsubstituted C.sub.1-6 alkyl or
substituted or unsubstituted aryl;
[0116] R.sub.z is halo, such as bromo, chloro, iodo or fluoro;
and
[0117] R is a substituted or unsubstituted, saturated or
unsaturated alkyl group, e.g., a C.sub.1-6 alkyl or alkenyl group
(such as methyl, ethyl, propyl, butyl, ethenyl, propenyl, allyl,
butenyl, etc.); a substituted or unsubstituted aliphatic or
aromatic acyl group, e.g., a C.sub.1-6 aliphatic acyl group such as
acetyl or an aromatic acyl group such as benzoyl; a substituted or
unsubstituted, saturated or unsaturated alkoxy or aryloxy carbonyl
group, such as methyl carbonate and phenyl carbonate; substituted
or unsubstituted sulphonyl imidazolide; substituted or
unsubstituted aliphatic or aromatic amino carbonyl group, such as
phenyl carbamate; substituted or unsubstituted alkyl imidate group
such as trichloroacetamidate; substituted or unsubstituted,
saturated or unsaturated phosphonate, such as diethylphosphonate;
substituted or unsubstituted aliphatic or aromatic sulphonyl group,
such as tosylate; or hydrogen.
[0118] Oxathiolane compounds of formula (Ia), i.e., compounds of
formula (I) wherein Z is S, S.dbd.O or SO.sub.2, and their
pharmaceutically acceptable derivatives may be prepared according
to the processes discussed herein or by any method known in the art
for the preparation of compounds of analogous structure.
[0119] One process according to the invention is illustrated in
SCHEME 1. Although this process is illustrated using specific
reagents and compounds, it will be obvious to one of skill in the
art that suitable alternative reactants may be used to prepare
analogous products as depicted, for example, in SCHEME 1A.
[0120] The various steps involved in the synthesis as illustrated
in SCHEME 1 may be briefly described as follows: ##STR22##
##STR23##
[0121] Step 1: Commercial bromoacetaldehyde diethyl acetal (or an
analogous halo alkyl acetal of the formula
R.sub.zCH.sub.2(OR.sub.x).sub.2), is treated in boiling DMF with an
excess of potassium thiobenzoate to give the benzoylthio acetal of
formula (V).
[0122] Step 2: The benzoyl group of formula (V) is hydrolyzed with
sodium hydroxide in an aqueous organic solvent to give the known
mercaptoacetal shown in formula (VI) (G. Hesse and I. Jorder,
"Mercaptoacetaldehyde and dioxy-1,4-dithiane", Chem. Ber., 85, pp.
924-32 (1952)).
[0123] Step 3: Glycerol 1-monobenzoate prepared according to the
literature (E. G. Hallonquist and H. Hibbert, "Studies on reactions
relating to carbohydrates and polysaccharides. Part XLIV: Synthesis
of isomeric bicyclic acetal ethers", Can. J. Research, 8, pp.
129-36 (1933)), is oxidized with sodium metaperiodate to give the
known benzoyloxyacetaldehyde of formula (VII) (C. D. Hurd and E. M.
Filiachione, "A new approach to the synthesis of aldehyde sugars",
J. Am. Chem. Soc., 61, pp. 1156-59 (1939)).
[0124] Step 4: The aldehyde of formula (VII) or any aldehyde of the
formula R.sub.yCOOCH.sub.2CHO is then condensed with the
mercaptoacetal of formula (VI) or any mercaptoacetal of the formula
HSCH.sub.2CH(OR.sub.X).sub.2 in a compatible organic solvent, such
as toluene, containing a catalytic amount of a strong acid to give
the novel intermediate shown in formula (VIII).
[0125] Step 5: The 1,3-oxathiolane of formula (VIII) is then
reacted with a purine or pyrimidine base (e.g., cytosine)
previously silylated with, for example, hexamethyldisilazane in a
compatible solvent using a Lewis acid or trimethylsilyl triflate to
give intermediate of formula (IX).
[0126] Step 6: The amine function of the compound shown in formula
(IX) is acetylated with acetic anhydride to yield the intermediate
of formula (X) as cis- and trans-isomers which are separated,
preferably by fractional crystallization, to give pure cis-(X) and
pure trans-(X).
[0127] Step 7: The cis- or trans-isomers of formula (X) are treated
with methanolic ammonia to obtain the desired product shown in
formula (XI) as cis- and trans-isomers.
[0128] Step 8: The preceding isomers of formula (XI) are treated
with an oxidizing agent which may be a suitable peracid in a
compatible solvent to give the 5-oxide (sulfoxide) of formula
(XII).
[0129] This synthesis is applicable to any nucleoside base
analogue, as would be obvious to those skilled in the art of
nucleoside chemistry. Other compounds defined by formula (Ia) may
be obtained similarly from intermediate VII by using the
appropriate heterocyclic compound in place of cytosine in Step 5.
In Step 4, other esters of hydroxyacetaldehyde such as aliphatic
acyl or substituted aroyl groups can be used following the same
sequence of steps leading to the compounds of formula (XI) and
formula (XII), respectively.
[0130] A second process according to this invention for producing
oxathiolane compounds is illustrated in SCHEME 2. Although this
process is illustrated using specific reagents and compounds, it
will be obvious to one of skill in the art that suitable analogous
reactants may be used to prepare analogous products, as depicted,
for example, in SCHEME 2A.
[0131] The various steps involved in the synthesis as illustrated
in SCHEME 2 may be briefly described as follows: ##STR24##
##STR25##
[0132] Step 1: A mercaptoacetaldehyde monomer produced from the
dimer in a solvent such as pyridine is reacted directly with a
benzoyloxyacetaldehyde of formula (VII) or any aldehyde of the
formula R.sub.yCOOCH.sub.2CHO to yield an oxathiolane lactol of
formula (XIII).
[0133] Step 2: The hydroxyl group of the compound of formula (XIII)
is converted to a leaving group with a suitable reagent such as
acetyl chloride in a compatible organic solvent to yield an
important oxathiolane intermediate of formula (XIV).
[0134] Step 3: The oxathiolane intermediate of formula (XIV) is
reacted with a previously silylated purine or pyrimidine base to
give, for example, a cytosin-1'-yl oxathiolane of formula (IX).
[0135] Step 4: The amine function of the compound shown in formula
(IX) is acylated with acetic anhydride in a solvent such as
pyridine to yield a compound of formula (X) which provides for
easier separation of isomers.
[0136] Step 5: The benzoate and acetyl functions of the compound of
formula (X) are hydrolyzed under basic conditions to yield an
oxathiolane of formula (XI).
[0137] A third process for producing oxathiolane compounds is
illustrated in SCHEME 3. Although this process is illustrated using
specific reagents and compounds, it will be obvious to one of skill
in the art that suitable analogous reactants may be used to prepare
analogous products, as depicted, for example, in SCHEME 3A.
[0138] The various steps involved in the synthesis as illustrated
in SCHEME 3 may be briefly described as follows: ##STR26##
##STR27## ##STR28##
[0139] Step 1: Mercaptoacetaldehyde monomer produced from the dimer
in a solvent such as pyridine is reacted directly with ethyl
glyoxylate or any organic glyoxylate of the formula R.sub.yOOCCHO
to yield an oxathiolane lactol of formula (XV).
[0140] Step 2: The hydroxyl group of the compound of formula (XV)
is converted to a leaving group with a suitable reagent such as
acetyl chloride in a compatible organic solvent to yield an
important oxathiolane intermediate of formula (XVI).
[0141] Step 3: The oxathiolane intermediate of formula (XVI) is
reacted with a previously silylated purine or pyrimidine base,
e.g., uracil, in the presence of a Lewis acid or preferably
trimethylsilyl iodide to give, e.g., a uracil-1'-yl oxathiolane of
formula (XVII) predominantly as the cis-isomer.
[0142] Step 4: The ester group of the oxathiolane of formula (XVII)
is selectively reduced with a suitable reducing agent such as
sodium borohydride in a compatible organic solvent such as methanol
to yield an oxathiolane nucleoside of formula (XVIII).
[0143] Step 5: The hydroxyl group of the compound of formula
(XVIII) is protected with a suitable silyl protecting group such as
t-butyl-dimethyl silyl in an appropriate solvent such as dimethyl
formamide (DMF) to yield an oxathiolane of formula (XIX).
[0144] Step 6: The uracil base of formula (XIX) can be
interconverted to another base, such as cytosine, by reaction with
a suitable reagent such as p-chlorophenoxy phosphorous oxychloride
followed by amination with, e.g., ammonia in methanol to yield an
oxathiolane of formula (XX).
[0145] Step 7: The silyl group of the compound of formula (XX) is
removed under neutral conditions using a suitable reagent such as
tetra n-butyl ammonium fluoride in a suitable solvent such as
tetrahydrofuran to yield the oxathiolane of formula (XI).
[0146] A fourth process according to this invention for producing
oxathiolane compounds is illustrated in SCHEME 4. Although this
process is illustrated using specific reagents and compounds, it
will be obvious to one of skill in the art that suitable analogous
reactants may be used to prepare analogous products, as depicted,
for example, in SCHEME 4A.
[0147] The various steps involved in the synthesis as illustrated
in SCHEME 4 may be briefly described as follows: ##STR29##
##STR30##
[0148] Step 1: The hydroxyl group of the intermediate of formula
XV, or corresponding R.sub.y-substituted intermediate (see SCHEME
3, step 1), is converted to a leaving group with a suitable reagent
such as methyl chloroformate in a compatible organic solvent to
yield an important intermediate of formula (XXI).
[0149] Step 2: The ester group of the intermediate of formula (XXI)
is selectively reduced with a suitable reducing agent such as
sodium borohydride in a compatible organic solvent such as methanol
and the resultant hydroxyl group is directly protected with a
suitable group such as t-butyl diphenyl silyl to yield an
oxathiolane of formula (XXII).
[0150] Step 3: The oxathiolane of formula (XXII) is reacted with a
previously silylated purine or pyrimidine base, such as cytosine to
give, e.g., a cytosin-1'-yl oxathiolane of formula (XXIII).
[0151] Step 4: The amine function of the compound shown in formula
(XXIII) is acylated, e.g., with acetic anhydride in a solvent such
as pyridine to yield a compound of formula (XXIV) which provides
for easier separation of isomers.
[0152] Step 5: The silyl and acetyl functions of the compound of
formula (XXIV) are hydrolyzed under basic conditions to yield an
oxathiolane of formula (XI).
[0153] In a fifth process the oxathiolane compounds of formula
(Ia), in which Z is S, S.dbd.O or SO.sub.2, may be prepared by the
reaction of a compound of formula (LIX) ##STR31## with a compound
of formula (LX) ##STR32## wherein P is a protecting group, followed
by removal of the protecting group. The compounds of formula (LIX)
may be prepared for reaction by a suitable epoxide (LXI) ##STR33##
with an appropriate sulphur-containing compound, e.g., sodium
thioacetate. Compounds of formula (LXI) are either known in the art
or may be obtained by analagous processes.
[0154] In a sixth process of this invention, the oxathiolane
compounds of formula (Ia) may be made by converting an intermediate
of formula (LXII) ##STR34## to a compound of formula (Ia) by
conversion of the anomeric NH.sub.2 to the desired purine or
pyrimidine base by methods well known in the art of nucleoside
chemistry.
[0155] The dioxolane compounds of formula (Ib) and their
pharmaceutically acceptable derivatives may be prepared by the
processes according to this invention or by any method known in the
art for preparation of compounds of analogous structure.
[0156] One such process for preparing dioxolane compounds of
formula (Ib) is outlined in SCHEME 5. Although this process is
illustrated using specific reagents and compounds, it will be
obvious to one of skill in the art that suitable alternative
reactants may be used to prepare analogous products, as depicted,
for example, in SCHEME 5A.
[0157] The various steps involved in the synthesis illustrated in
SCHEME 5 may be briefly described as follows: ##STR35##
##STR36##
[0158] Step 1: Chloroacetaldehyde diethyl acetal (or an analogous
halo alkyl acetal) is treated with glycerol in an inert solvent
according to the procedure reported by E. G. Hallonquist and H.
Hibbert, "Studies In Reactions Relating To Carbohydrates And
Polysaccharides--Part XLIV: Synthesis Of Isomeric Bicyclic Acetal
Ethers", Can. J. Res., 8, pp. 129-136 (1933) to produce an
intermediate of formula (XXV).
[0159] Step 2: The primary alcohol function of the dioxolane
intermediate of formula (XXV) is treated with an oxidizing reagent
such as chromic acid (which may be complexed with pyridine) in a
compatible organic solvent to give the corresponding dioxolane
carboxylic acid of formula (XXVI).
[0160] Step 3: The acid of formula (XXVI) is converted to a mixed
anhydride using an alkyl chloroformate and subjected to a
Bayer-Villiger oxidation with an organic peracid such as
m-chloroperbenzoic acid to yield the corresponding
aroyloxydioxolane of formula (XXVII).
[0161] Step 4: Intermediate of formula (XXVII) is then reacted with
previously silylated purine or pyrimidine base such as thymine,
with, e.g., hexamethyldisilazane in a compatible solvent and the
reaction catalyzed by a Lewis acid or preferably by trimethylsilyl
triflate to give, e.g., the thymin-1'-yl dioxolane of formula
(XVI).
[0162] Step 5: The chlorine atom of formula (XXVIII) is displaced
by reaction with a benzoic acid salt in a compatible solvent such
as dimethyl formamide to give an intermediate of formula
(XXIX).
[0163] Step 6: The benzoate ester function is then hydrolyzed under
basic conditions to yield the desired end-product of formula
(XXX).
[0164] A second process for preparing further specific dioxolane
compounds of the present invention is illustrated in SCHEME 6.
Although this process is illustrated using specific reagents and
compounds, it will be obvious to one of skill in the art that
suitable alternative reactants may be used to prepare analogous
products, as depicted, for example, in SCHEME 6A.
[0165] The various steps involved in the synthesis illustrated in
SCHEME 6 may be briefly described as follows: ##STR37## ##STR38##
##STR39## ##STR40##
[0166] Step 1: The chlorine atom of starting dioxolane of formula
(XXV) is displaced by a benzoic (or acetic) acid salt in a solvent
such a dimethylformamide to yield the diol monoester of formula
(XXXI).
[0167] Step 2: The hydroxymethyl group of formula (XXXI) is
oxidized with a suitable reagent such as chromic acid (which may be
complexed with pyridine) in a compatible organic solvent to give
the dioxolane carboxylic acid of formula (XXXII).
[0168] Step 3: The acid of formula (XXXII) is then subjected to
Bayer-Villiger oxidation by the procedure outlined in Step 2 of
SCHEME 5 above to give the corresponding aroyloxy-dioxolane of
formula (XXXIII).
[0169] Step 4: The intermediate of formula (XXXIII) is reacted with
a previously silyated purine or pyrimidine base, such as cytosine,
under the reaction conditions outlined in Step 3 of SCHEME 5 to
give, e.g., the cytosin-1'-yl dioxolane of formula (XXXIV).
[0170] Step 5: The amine function of formula (XXXIV) is acylated
with acetic anhydride in a solvent such as pyridine to give the
compound of formula (XXXV) which provides for easier separation of
isomers.
[0171] Step 6: The ester and acetyl functions of formula (XXXV) are
hydrolyzed under basic conditions to yield the desired end-product
of formula (XXXVI).
[0172] Step 7: ((XXXIII) to (XXXVII)) The intermediate of formula
(XXXIII) is alternatively reacted with a purine or pyrimidine base,
such as adenine, by the procedure outlined above in Step 3 of
SCHEME 5 to give the compound of formula (XXXVII).
[0173] Step 8: ((XXXVII) to (XXXVIII)) The ester function of
formula (XXXVII) is hydrolyzed under basic conditions to yield the
desired end-product of formula (XXXVIII).
[0174] Step 9: ((XXXIII) to (XXXIX)) The intermediate of formula
(XXXIII) is alternatively reacted with 2-amino-6-chloropurine under
the conditions outlined in Step 3 of SCHEME 5 to give a compound of
formula (XXXIX).
[0175] Step 10: ((XXXIX) to (XL)) The intermediate (XXXIX) is
hydrolyzed under basic conditions to yield the desired end-product
of formula (XL).
[0176] Step 11: ((XL) to (XLI)) The chlorine atom of formula (XL)
is removed by catalytic hydrogenation over Pd/C to give the
2'-amino-purin-9'-yl dioxolane of formula (XLI).
[0177] Step 12: The above intermediate (XXXIX) is alternatively
reacted with excess ammonia under pressure whereupon the
2',6'-diamino-purin-9'-yl dioxolane of formula (XLII) is
produced.
[0178] Step 13: The compound of formula (XL) is alternatively
subjected to boiling sodium hydroxide to give the desired
end-product guanin-9'-yl dioxolane of formula (XLIII).
[0179] A third process for preparing dioxolane compounds of the
present invention is illustrated in SCHEME 7. Although this process
is illustrated using specific reagents and compounds, it will be
obvious to one of skill in the art that suitable alternative
reactants may be used to prepare analogous products, as depicted,
for example, in SCHEME 7A.
[0180] The various steps involved in the synthesis illustrated in
SCHEME 7 may be briefly described as follows: ##STR41##
##STR42##
[0181] Step 1: Benzoyloxyacetaldehyde (or any aldehyde of the
formula R.sub.yCOOCH.sub.2CHO) is converted to the
bis(2-methoxyethyl)acetal of formula (XLIV) in, e.g., boiling
toluene in the presence of a Lewis acid.
[0182] Step 2: The benzoyl group of formula (XLIV) is hydrolyzed
with, e.g., potassium carbonate in an aqueous organic solvent to
give the hydroxyacetal shown in formula (XLV).
[0183] Step 3: The aldehyde of formula (VII) or any aldehyde of the
formula R.sub.yCOOCH.sub.2CHO is condensed with the hydroxyacetal
of formula (XLV) or any hydroxyacetal of the formula
HSCH.sub.2CH(OR.sub.X).sub.2 in a compatible organic solvent, such
as toluene, containing a catalytic amount of a strong acid to give
the novel intermediate of formula (XLVI).
[0184] Step 4: The 1,3-dioxolane of formula (XLVI) is then reacted
with a previously silylated purine or pyrimidine base, such as
cytosine, with, e.g., hexamethyldisilazane in a compatible solvent
using a Lewis acid such as titanium tetrachloride to give the
intermediate of formula (XXXIV).
[0185] Step 5: The amine function of the compound of formula (XXIV)
is acetylated with acetic anhydride to yield the intermediate
(XXXV) for easier separation of cis- and trans-isomers.
[0186] Step 6: The cis- and/or trans-isomers of formula (XXXV) are
treated with, e.g., methanolic ammonia to give the desired product
shown in formula (XXXVI) as cis- and trans-isomers.
[0187] A preferred process for preparing dioxolane compounds of the
present invention is illustrated in SCHEME 8. Although this process
is illustrated using specific reagents and compounds, it will be
obvious to one of skill in the art that suitable alternative
reactants may be used to prepare analogous products, as depicted,
for example, in SCHEME 8A.
[0188] The various steps involved in the synthesis illustrated in
SCHEME 8 may be briefly described as follows: ##STR43## ##STR44##
Step 1: The aldehyde of formula (VII) or any aldehyde of the
formula R.sub.yCOOCH.sub.2CHO is condensed with the known epoxide
described in R. L. Wasson and H. O. House, "Preparation of
Isophorone Oxide", Organic Synthesis Collective, Vol. IV, p. 552
(1963) in an appropriate solvent such as benzene and a suitable
Lewis acid such as tetraethylammonium bromide to give dioxolane of
formula (XLVIII).
[0189] Step 2: The ketone of formula (XLVIII) is subjected to a
Bayer-Willinger oxidation with an organic peracid such as
m-chloroperbenzoic acid to yield the corresponding acetoxydioxolane
(XLIX).
[0190] Step 3: The dioxolane of formula (XLIX) is then reacted with
a previously silylated purine or pyrimidine base, such as cytosine,
with, e.g., hexamethyldisilazane in a suitable solvent using a
Lewis acid or preferrably trimethylsilyl triflate to give the
intermediate of formula (XXXIV).
[0191] Step 4: The amine function of the compound of formula (XXIV)
is acetylated with, e.g., acetic anhydride to yield the
intermediate (XXXV) for easier separation of cis- and
trans-isomers.
[0192] Step 5: The cis- and/or trans-isomers of formula (XXXV) are
treated with methanolic ammonia to give the desired product shown
in formula (XXXVI) as cis- and trans-isomers.
[0193] In the above-identified processes for making the oxathiolane
and dioxolane compounds of this invention, the following
intermediates are of particular importance: [0194]
2-thiobenzoylacetaldehyde diethylacetal (V); [0195] cis- and
trans-2-benzoyloxymethyl-5-ethoxy-1,3-oxathiolane (VIII); [0196]
cis- and trans-2-benzoyloxymethyl-5-hydroxy-1,3-oxathiolane (XIII);
[0197] cis- and trans-2-benzoyloxymethyl-5-acetoxy-1,3-oxathiolane
(XIV); [0198] cis- and
trans-2-ethoxycarbonyl-5-hydroxy-1,3-oxathiolane (XV); [0199] cis-
and trans-2-ethoxycarbonyl-5-acetoxy-1,3-oxathiolane (XVI); [0200]
cis- and trans-2-ethoxycarbonyl-5-(uracil-1'-yl)-1,3-oxathiolane
(XVII); [0201] cis- and
trans-2-t-butyldimethylsilyloxymethyl-5-(uracil-1'-yl)-1,3-oxathiolane
(XIX); [0202] cis- and
trans-2-t-butyldimethylsilyloxymethyl-5-(cytosin-1'-yl)-1,3-oxathiolane
(XX); [0203] cis- and
trans-2-ethoxycarbonyl-5-(methoxycarbonyloxy)-1,3-oxathiolane
(XXI); [0204] cis- and
trans-2-t-butyldiphenylsilyloxymethyl-5-(methoxycarbonyloxy)-1,3-oxathiol-
ane (XXII); [0205] cis- and
trans-2-t-butyldiphenylsilyloxymethyl-5-(cytosin-1'-yl)-1,3-oxathiolane
(XXIII); [0206] cis- and
trans-2-t-butyldiphenylsilyloxymethyl-5-(N.sub.4-acetylcytosin-1'-yl)-1,3-
-oxathiolane (XXIV); [0207] cis- and
trans-2-chloromethyl-4-(m-chlorobenzoyloxy)-1,3-dioxolane (XXVII);
[0208] cis- and trans-2-benzoyloxymethyl-1,3-dioxolane-4-carboxylic
acid (XXXII); [0209] cis- and
trans-2-benzoyloxymethyl-4-(m-chlorobenzoyloxy)-1,3-dioxolane
(XXXIII); [0210] 2-benzoyloxyacetaldehyde bis(2-methoxyethyl)acetal
(XLIV); [0211] 2-hydroxyacetaldehyde bis(2-methoxyethyl)acetal
(XLV); [0212] cis- and
trans-2-benzoyloxymethyl-4-(2-methoxyethoxy)-1,3-dioxolane (XLVI);
[0213] cis- and trans-2-benzoyloxymethyl-4-acetyl-1,3-dioxolane
(XLVIII); and [0214] cis- and
trans-2-benzoyloxymethyl-4-acetoxy-1,3-dioxolane (XLIX).
[0215] In addition, the following intermediates, although not
specifically depicted in the above identified processes, are
important intermediates for making the oxathiolane and dioxolane
compounds of this invention: [0216] 2-thiobenzoylacetaldehyde
bis(2-methoxyethyl)acetal; [0217] 2-thioacetaldehyde
bis(2-methoxyethyl acetal; [0218] cis- and
trans-2-benzoyloxymethyl-5-(2-methoxyethoxy)-1,3-oxathiolane.
[0219] cis- and trans-2-hydroxymethyl-5-hydroxy-1,3-oxathiolane;
and [0220] cis- and trans-2-acetoxymethyl-5-1,3-oxathiolane.
[0221] Many of the reactions described hereinabove have been
extensively reported in the context of purine nucleoside synthesis,
for example, in "Nucleoside Analogues--Chemistry, Biology and
Medical Applications", R. T. Walker et al., Eds, Plenum Press, New
York (1979) at pages 193-223, the text of which is incorporated by
reference herein.
[0222] As used in the processes of this invention, a "leaving
group" is an atom or group which is displaceable upon reaction with
an appropriate base, with or without a Lewis acid. Suitable leaving
groups include alkoxy carbonyl groups such as ethoxy carbonyl;
halogens such as iodine, bromine, chlorine, or fluorine; amido;
azido; isocyanato; substituted or unsubstituted, saturated or
unsaturated thiolates, such as thiomethyl or thiophenyl;
substituted or unsubstituted, saturated or unsaturated selenino
compounds, such as phenyl selenide or alkyl selenide; substituted
or unsubstituted, saturated or unsaturated aliphatic or aromatic
ketones such as methyl ketone; or --OR where R is a substituted or
unsubstituted, saturated or unsaturated alkyl group, e.g.,
C.sub.1-6 alkyl or alkenyl group; a substituted or unsubstituted
aliphatic or aromatic acyl group, e.g., a C.sub.1-6 aliphatic acyl
group such as acetyl and an aromatic acyl group such as benzoyl; a
substituted or unsubstituted, saturated or unsaturated alkoxy or
aryloxy carbonyl group, such as methyl carbonate and phenyl
carbonate; substituted or unsubstituted sulphonyl imidazolide;
substituted or unsubstituted aliphatic or aromatic amino carbonyl
group, such as phenyl carbamate; substituted or unsubstituted alkyl
imidate group such as trichloroacetamidate; substituted or
unsubstituted, saturated or unsaturated phosphonates, such as
diethylphosphonate; substituted or unsubstituted aliphatic or
aromatic sulphonyl group, such as tosylate; or hydrogen.
[0223] It will be appreciated that the reactions of the
above-described processes may require the use of, or conveniently
may be applied to, starting materials having protected functional
groups, and deprotection might thus be required as an intermediate
or final step to yield the desired compound. Protection and
deprotection of functional groups may be effected using
conventional means. Thus, for example, amino groups may be
protected by a group selected from aralkyl (e.g., benzyl), acyl or
aryl (e.g., 2,4-dinitrophenyl); subsequent removal of the
protecting group being effected when desired by hydrolysis or
hydrogenolysis as appropriate using standard conditions. Hydroxyl
groups may be protected using any conventional hydroxyl protecting
group, for example, as described in "Protective Groups in Organic
Chemistry", Ed. J. F. W. McOmie (Plenum Press, 1973) or "Protective
Groups in Organic Synthesis" by Theodora W. Greene (John Wiley and
Sons, 1981). Examples of suitable hydroxyl protecting groups
include groups selected from alkyl (e.g., methyl, t-butyl or
methoxymethyl), aralkyl (e.g., benzyl, diphenylmethyl or
triphenylmethyl), heterocyclic groups such as tetrahydropyranyl,
acyl, (e.g., acetyl or benzoyl) and silyl groups such as
trialkylsilyl (e.g., t-butyldimethylsilyl). The hydroxyl protecting
groups may be removed by conventional techniques. Thus, for
example, alkyl, silyl, acyl and heterocyclic groups may be removed
by solvolysis, e.g., by hydrolysis under acidic or basic
conditions. Aralkyl groups such as triphenylmethyl may similarly be
removed by solvolysis, e.g., by hydrolysis under acidic conditions.
Aralkyl groups such as benzyl may be cleaved, for example, by
treatment with BF.sub.3/etherate and acetic anhydride followed by
removal of acetate groups so formed at an appropriate stage in the
synthesis. Silyl groups may also conveniently be removed using a
source of fluoride ions such as tetra-n-butylammonium fluoride.
[0224] In the above processes the compounds of formula (I) are
generally obtained as a mixture of the cis and trans isomers.
[0225] These isomers may be separated, for example, by acetylation,
e.g., with acetic anhydride followed by separation by physical
means, e.g., chromatography on silica gel and deacetylation, e.g.,
wish methanolic ammonia or by fractional crystallization.
[0226] Pharmaceutically acceptable salts of the compounds of the
invention may be prepared as described in U.S. Pat. No. 4,383,114,
the disclosure of which is incorporated by reference herein. Thus,
for example, when it is desired to prepare an acid addition salt of
a compound of formula (I), the product of any of the above
procedures may be converted into a salt by treatment of the
resulting free base with a suitable acid using conventional
methods. Pharmaceutically acceptable acid addition salts may be
prepared by reacting the free base with an appropriate acid
optionally in the presence of a suitable solvent such as an ester
(e.g., ethyl acetate) or an alcohol (e.g., methanol, ethanol or
isopropanol). Inorganic basic salts may be prepared by reacting the
free base with a suitable base such as an alkoxide (e.g., sodium
methoxide) optionally in the presence of a solvent such as an
alcohol (e.g., methanol). Pharmaceutically acceptable salts may
also be prepared from other salts, including other pharmaceutically
acceptable salts, of the compounds of formula (I) using
conventional methods.
[0227] A compound of formula (I) may be converted into a
pharmaceutically acceptable phosphate or other ester by reaction
with a phosphorylating agent, such as POCl.sub.3, or a suitable
esterifying agent, such as an acid halide or anhydride, as
appropriate. An ester or salt of a compound of formula (I) may be
converted to the parent compound, for example, by hydrolysis.
[0228] Where the compound of formula (I) is desired as a single
isomer it may be obtained either by resolution of the final product
or by stereospecific synthesis from isomerically pure starting
material or any convenient intermediate.
[0229] Resolution of the final product, or an intermediate or
starting material therefore may be effected by any suitable method
known in the art: see for example, Stereochemistry of Carbon
Compounds, by E. L. Eliel (McGraw Hill, 1962) and Tables of
Resolving Agents, by S. H. Wilen.
[0230] The invention will be further described by the following
examples which are not intended to limit the invention in any way.
All temperatures are in degrees celsius.
EXAMPLES
Example 1
2-thiobenzoyl acetaldehyde diethylacetal
[0231] C.sub.6H.sub.5COS--CH.sub.2CH(OC.sub.2H.sub.5).sub.2 (V)
[0232] To a solution of potassium t-butoxide (11.5 g. 0.11 mol) in
DMF (100 ml) was added thiobenzoic acid (17 g. 0.11 mol) and the
solution partially evaporated in vacuo, benzene added in two
consecutive portions (2.times.30 ml) and evaporated in vacuo each
time. To the residual DMF solution was added bromoacetaldehyde
diethylacetal (20.3 g. 0.1 mol) and the mixture stirred at 120' for
15 h. After cooling, it was poured onto water (500 ml), the product
extracted with ether (3.times.200 ml), the extract washed with
aqueous NaHCO.sub.3 followed by water, then dried and the solvent
removed in vacuo. The residue was distilled in vacuo to give 17.2
g. of pure (V), b.p. 131-133.degree./0.07 mm. It was characterized
by .sup.1H-NMR .delta.(ppm in CDCl.sub.3): 7.97 (d, 2H; aromatic)
7.47 (m, 3H; aromatic) 4.59 (t, 1H; --CH(OC.sub.2H.sub.5).sub.2))
3.66 (m, 4H; 2.times.OCH.sub.2CH.sub.3) 3.30 (d, 2H; SCH.sub.2--)
1.23 (t, 6H; 2.times.OCH.sub.2CH.sub.3)
Example 2
Mercaptoacetaldehyde Diethylacetal
[0233] HSCH.sub.2CH(OC.sub.2H.sub.5).sub.2 (VI)
[0234] The preceding thiobenzoyl derivative (V) (17.2 g) was
dissolved in 100 ml THF followed by the addition of 6 g NaOH in 20
ml H.sub.2O. The mixture was refluxed under N.sub.2 for 15 h, then
cooled and diluted with water (200 ml) and the product extracted
with ether (3.times.200 ml). The extract was dried, the solvent
removed in vacuo and the residue distilled in vacuo to yield 7.1 g
of pure (VI), b.p. 60-62.degree./18 mm. It was characterized by
.sup.1H NMR .delta.(ppm in CDCl.sub.3): 4.51 (t, 1H;
CH(OC.sub.2H.sub.5).sub.2) 3.51 (m, 4H; 2.times.OCH.sub.2CH.sub.3)
2.65 (dd, 2H; HS--CH.sub.2) 1.54 (t, 1H; HS--) 1.23 (t, 6H;
2.times.OCH.sub.2CH.sub.3)
Example 3
Benzoyloxyacetaldehyde
[0235] C.sub.6H.sub.5COOCH.sub.2CHO (VII)
[0236] This known intermediate was prepared by a previously
unreported method from the known 1-benzoyl glycerol. Thus, 50 g of
the latter in a mixture of 500 ml of CH.sub.2Cl.sub.2 and 25 ml of
H.sub.2O was treated portion-wise with 80 g of NaIO.sub.4 under
vigorous stirring at room temperature. After addition, stirring was
continued for 2 h after which time 100 g of MgSO.sub.4 was added
and stirring continued for 30 min. The mixture was filtered, the
filtrate evaporated in vacuo and the residue distilled in vacuo to
yield 26 g of pure (VII) b.p. 92-94.degree./0.25 mM. .sup.1H NMR
(200 MH.sub.z; TMS as internal reference)
[0237] .delta.(ppm in CDCl.sub.3,): 9.71 (s, 1H; --CHO) 8.11 (d,
2H; aromatic) 7.60 (m, 1H; aromatic) 7.46 (m, 2H; aromatic) 4.88
(s, 2H; --CH.sub.2CHO)
Example 4
2-Benzoyloxymethyl-5-ethoxy-1,3-oxathiolane
[0238] ##STR45##
[0239] The preceding mercaptoacetaldehyde acetal (VI) (7 g) was
mixed in 100 ml of toluene with 7 g of the above
benzoyloxyacetaldehyde (VII), a few crystals of para-toluene
sulfonic acid added and the mixture placed in an oil-bath at
120.degree. under N.sub.2. The formed ethanol was allowed to
distill over, the mixture kept at 120.degree. for an additional 30
minutes, then cooled and washed with aqueous NaHCO.sub.3, dried and
evaporated in vacuo. The residue was distilled in vacuo to yield
9.8 g of pure (VIII) as a mixture of cis- and trans-isomers,
[0240] b.p. 140-143.degree./0.1 mm; R.sub.f 0.51
(hexane-EtOAc);
[0241] .sup.1H NMR .delta.(ppm in CDCl.sub.3): 8.05 (m, 2H;
aromatic) 7.57 (m, 1H; aromatic) 7.43 (m, 2H; aromatic) 5.55 (m,
2H; C.sub.5--H, C.sub.2--H) 4.55 (m, 2H;
C.sub.2--C.sub.6H.sub.5CO.sub.2CH.sub.2) 3.80 (m, 1H;
C.sub.5--OCHCH.sub.3) 3.76 (m, 1H; C.sub.5--OCHCH.sub.3) 3.17 (m,
2H; C.sub.4--H.sub.2) 1.21 (t, 3H; C.sub.5--OCH.sub.2CH.sub.3)
Example 5
Cis- and
trans-2-benzoyloxymethyl-5-(cytosin-1'-yl)-1,3-oxathiolane
[0242] ##STR46##
[0243] A mixture of 2.7 g of cytosine, 30 ml of
hexamethyldisilazane (HMDS) and 0.3 ml of trimethylsilyl chloride
(TMSCl) was heated under reflux under dry N.sub.2 until a clear
solution resulted (3 hours) and the excess reagents evaporated in
vacuo. The remaining volatiles were removed under high vacuum (15
min.), the solid residue taken up in 250 ml of 1,2-dichloroethane
and 5 g of the above intermediate (VIII) in 50 ml of dichloroethane
added under dry argon followed by 4.7 ml of trimethylsilyl triflate
(TMST.sub.f). After 3 days of heating under reflux under argon, it
was cooled and poured onto 300 ml of saturated aqueous NaHCO.sub.3.
The organic layer was collected, the aqueous phase extracted with
CH.sub.2Cl.sub.2 (2.times.100 ml) and the combined extracts washed
with water, dried and evaporated in vacuo. The residue was purified
by chromatography on silica gel using CH.sub.2Cl.sub.2:CH.sub.3OH
9:1 as the eluant to give 2.5 g of a pure mixture of cis- and
trans-(IX) in a 1:1 ratio as ascertained by .sup.1H NMR. These were
separated as the N-acetyl derivatives as described in the following
example.
Example 6
Cis- and trans-isomers of
2-benzoyloxymethyl-5-(N.sub.4'-acetyl-cytosin-1'-yl)-1,3-oxathiolane
[0244] ##STR47##
[0245] The preceding mixture (IX) (2.5 g) in 100 ml of dry pyridine
containing 0.1 g of 4-dimethylaminopyridine (DMAP) was treated with
acetic anhydride (7 ml) at room temperature and after 16 hours, the
mixture was poured onto cold water followed by extraction with
CH.sub.2Cl.sub.2 (3.times.150 ml). The extract was washed with
water, dried, and evaporated in vacuo. Toluene was added to the
residue, then evaporated in vacuo and the residual oil purified by
chromatography on silica gel using EtOAc:CH.sub.3OH 99:1 as the
eluant to yield 1.35 g of pure trans-(X) as the fast moving product
and 1.20 g of pure cis-(X) as the slow moving component. These were
characterized by H NMR spectroscopy.
[0246] trans-(X): m.p. 158-160.degree.; R.sub.f: 0.48
EtOAc:CH.sub.3OH 95:5
[0247] U.V.: (CH.sub.3OH) Lambda max: 297 nm
[0248] .sup.1H NMR .delta.(ppm in CDCl.sub.3): 9.00 (b, 1H;
C.sub.4'--NH--Ac) 8.06 (m, 2H; aromatic) 7.74 (d, 1H; C.sub.6'--H)
7.56 (m, 1H; aromatic) 7.47 (d, 1H; C.sub.5'--H) 7.45 (m, 2H;
aromatic) 6.53 (dd, 1H; C.sub.5--H) 5.89 (dd, 1H; C.sub.2--H) 4.46
(dd, 2H; C.sub.2--CH.sub.2OCOC.sub.6H.sub.5) 3.66 (dd, 1H;
C.sub.4--H) 3.32 (dd, 1H; C.sub.4--H) 2.25 (s, 3H;
NH--COCH.sub.3)
[0249] Cis-(X): m.p. 150-152.degree.; R.sub.f: 0.40 EtOAc:MeOH
95:5)
[0250] U.V.: (CH.sub.3OH) Lambda max: 297 nm
[0251] .sup.1H NMR .delta.(ppm in CDCl.sub.3): 9.03 (b, 1H; NH--Ac)
8.21 (d, 1H; C.sub.6'--H) 8.05 (m, 2H; aromatic) 7.60 (m, 1H;
aromatic) 7.50 (m, 2H; aromatic) 7.29 (d, 1H; C.sub.5'--H) 6.34
(dd, 1H; C.sub.5--H) 5.52 (dd, 1H; C.sub.2--H) 4.80 (dd, 2H;
C.sub.2--CH.sub.2OCOC.sub.6H.sub.5) 3.66 (dd, 1H; C.sub.4--H) 3.24
(dd, 1H; C.sub.4--H) 2.23 (s, 3H; NH--COCH.sub.3)
Example 7
Cis- and
trans-2-hydroxymethyl-5-(cytosin-1'-yl)-1,3-oxathiolane
[0252] ##STR48##
[0253] a) Trans-(XI): 375 mg of the preceding trans-(X) was
dissolved in 100 ml of methanolic ammonia at 24.degree. and after
stirring for 16 hours, the solvent was removed in vacuo and the
residue crystallized with ether. It was recrystallized from
ethanol-ether to yield 174 mg of pure product, m.p.>220.degree.
(dec). It was characterized by .sup.1H and .sup.13C NMR.
[0254] .sup.1H NMR .delta.(ppm in DMSO-d.sub.6): 7.57 (d, 1H;
C.sub.6'--H) 7.18 (d, 2H; C.sub.4'--NH.sub.2) 6.30 (dd, 1H;
C.sub.5--H) 5.68 (d, 1H; C.sub.5'--H) 5.48 (t, 1H; C.sub.2--H) 5.18
(t, 1H; C.sub.2--CH.sub.2OH) 3.45 (m, 3H;
C.sub.2--CH.sub.2OH+C.sub.4H) 3.06 (dd, 1H; C.sub.4--H)
[0255] U.V.: (CH.sub.3OH) Lambda max: 270 nm
[0256] .sup.13C NMR (DMSO-d.sub.6, Varian XL-300); .delta. in ppm:
C.sub.2'C.sub.4'C.sub.5'C.sub.6'C.sub.5C.sub.4C.sub.2CH.sub.2OH
154.71 165.70 93.47 140.95 87.77 36.14 86.80 64.71
[0257] b) Cis-(XI): treating 375 mg of cis-(X) by the same
preceding procedure led to 165 mg of pure product after
recrystallization from ethanol-ether, m.p. 171-173.degree.. It was
characterized by .sup.1H and .sup.13C NMR.
[0258] .sup.1H NMR: .delta.(ppm in DMSO-d.sub.6): 7.80 (d, 1H;
C.sub.6'--H) 7.20 (d, 2H; C.sub.4'--NH.sub.2) 6.18 (t, 1H;
C.sub.5--H) 5.70 (d, 1H; C.sub.5'--H) 5.14 (t, 1H;
C.sub.2--CH.sub.2OH) 3.71 (m, 2H; C.sub.2--CH.sub.2OH) 3.40 (dd,
1H; C.sub.4--H) 2.99 (dd, 1H; C.sub.4--H).
[0259] U.V.: (CH.sub.3OH) Lambda max: 270 nm
[0260] .sup.13C NMR .delta.(ppm in DMSO-d.sub.6)
C.sub.2'C.sub.4'C.sub.5'C.sub.6'C.sub.5C.sub.4C.sub.2CH.sub.2OH
154.63 165.59 93.86 140.91 86.47 36.22 85.75 62.79
Example 8
Cis-2-hydroxymethyl-5-(cytosin-1'-yl)-3-oxo-1,3-oxathiolane
[0261] ##STR49##
[0262] The preceding cis-(XI) (100 mg) in 30 ml of ice-cold
methanol was treated with 93 mg of metachloroperbenzoic acid and
after stirring for 15 min a white solid separated which was
collected and washed with 10 ml of methanol to give 45 mg of pure
sulfoxide isomer a. The methanol filtrates were evaporated in vacuo
and the solid residue washed with 15 ml of ethanolether (1:1) and
then with 30 ml of ether to give 50 mg of pure sulfoxide isomer b.
The isomers were characterized by .sup.1H NMR.
[0263] Isomer (XII)a: m.p.>270.degree. (dec); R.sub.f:0.30
(CH.sub.2Cl.sub.2-MeOH 3:1)
[0264] U.V.: (CH.sub.3OH) Lambda max: 270 nm
[0265] .sup.1H NMR .delta. (ppm in DMSO-d.sub.6): 7.68 (d, 1H;
C.sub.6'--H) 7.36 (s, 2H; C.sub.4'--NH.sub.2) 6.69 (dd, 1H;
C.sub.5--H) 5.76 (d, 1H; C.sub.5'--H) 5.47 (t, 1H;
C.sub.2--CH.sub.2OH) 4.63 (dd 1H; C.sub.2--H) 3.88 (m, 1H;
C.sub.2--CH--OH) 3.72 (m, 1H; C.sub.2--CH--OH) 3.36 (dd, 1H;
C.sub.4--H) 3.05 (dd, 1H; C.sub.4--H)
[0266] Isomer (XII).sub.b: m.p.>220.degree. (dec); R.sub.f:0.32
CH.sub.2Cl.sub.2:MeOH 3:1
[0267] .sup.1H NMR .delta. (ppm in DMSO-d.sub.6): 7.76 (d, 1H;
C.sub.6'--H) 7.28 (d, 2H; C.sub.4'--NH.sub.2) 6.66 (dd, 1H;
C.sub.5--H) 5.77 (d, 1H; C.sub.5'--H) 5.45 (t, 1H;
C.sub.2--CH.sub.2OH) 4.64 (t, 1H; C.sub.2--H) 3.77 (t, 2H;
C.sub.2--CH.sub.2OH) 3.65 (dd, 1H; C.sub.4--H) 3.17 (dd, 1H;
C.sub.4--H)
Example 9
Cis-2-hydroxymethyl-5-(N-dimethylamino methylene
cytosin-1'-yl)-1,3-oxathiolane
[0268] ##STR50##
[0269] 300 mg of
cis-2-hydroxymethyl-5-(cytosin-1'-yl)1,3-oxathiolane was suspended
in 10 ml of N-dimethylformamide dimethyl acetal (DMF-dimethyl
acetal). The mixture was stirred at room temperature overnight (18
hours). Volatile material was removed by evaporation under reduced
pressure. The residue was crystallized in ethanol-ether. It yielded
345 mg (93%) of pure product. m.p. 162-164.degree. C.; R.sub.f:
0.56 in CH.sub.2Cl.sub.2:MeOH 4:1
[0270] U.V.: Lambda max: 325 nm
[0271] .sup.1H NMR .delta.(ppm in DMSO-d.sub.6): 8.64 (s, 1H,
N.dbd.CH--N) 8.04 (d, 1H, C.sub.6'--H, J=7.2 Hz) 6.22 (t, 1H,
C.sub.5--H, J=4.9 Hz) 5.97 (d, 1H, C.sub.5'--H, J=7.2 Hz) 5.37 (t,
1H, --OH, J=5.8 Hz, D.sub.2O exchange) 5.22 (t, 1H, C.sub.2--H,
J=4.4 Hz) 3.77 (t, 2H, C.sub.2--CH.sub.2OH, J=4.9 Hz) 3.50 (dd, 1H,
C.sub.4--H, J=4.9 and 9.9 Hz) 3.17 (s, 3H, --CH.sub.3) 3.12 (dd,
1H, C.sub.4--H, J=4.2 and 11.9 Hz) 3.04 (s, 3H, --CH.sub.3)
Example 10
Bis-Cis-2-succinyloxymethyl-5-(cytosin-1'-yl)-1,3-oxathiolane
[0272] ##STR51##
[0273] 284 mg of cis-2-hydroxymethyl-5-(N,N-dimethylamino methylene
cytosin-1'-yl)-1,3-oxathiolane was dissolved in 10 ml of dry
pyridine and cooled at 0.degree. C. in an ice-bath. 60 .mu.l of
succinyl chloride was added via a syringe. The mixture was stirred
overnight (18 hours) and poured into 50 ml of saturated aqueous
NaHCO.sub.3 solution. The mixture was extracted with methylene
chloride (3.times.50 ml). The combined CH.sub.2Cl.sub.2 solution
was washed with water (2.times.50 ml) and dried over MgSO.sub.4.
After filtration, solvent was removed by evaporation under reduced
pressure. The foam residue was dissolved in 10 ml of
CH.sub.2Cl.sub.2 containing 5 ml of methanol. 2 ml of 80% aqueous
acetic acid was added and the mixture was stirred at room
temperature overnight. The mixture was evaporated to dryness. The
solid residue was purified on silica gel using
CH.sub.2Cl.sub.2:MeOH 4:1 as eluant. It yielded 145 mg (54%) of
pure product.
m.p. Dec >230.degree. C.; R.sub.f: 0.23 (in
CH.sub.2Cl.sub.2:MeOH 4:1)
[0274] U.V.: (MeOH) Lambda max: 271 nm
[0275] .sup.1H-NMR .delta.(ppm in DMSO-d.sub.6) 7.69 (d, 2H,
2.times.C.sub.6'--H, J=7.6 Hz) 7.28 (d, 4H, 2.times.NH.sub.2,
J=24.9 Hz, D.sub.2O exchange) 6.24 (t, 2H, 2.times.C.sub.5--H,
J=5.6 Hz) 5.76 (d, 2H, 2.times.C.sub.51'--H; J=7.4 Hz) 5.35 (t, 2H,
2.times.C.sub.2--H, J=4.5 Hz) 4.37 (d, 4H,
2.times.C.sub.2--CH.sub.2O--) 3.42 (dd, 2H, 2.times.C.sub.4--H,
J=5.5 and 10.9 Hz) 3.10 (dd, 2H, 2.times.C.sub.4--H, J=5.6 and 11.7
Hz) 2.60 (s, 4H, 2.times.-CH.sub.2--C--O)
Example 11
Cis- and
trans-2-benzoyloxymethyl-5-(6'-chloropurin-N-9'-yl)-1,3-oxathiola-
ne
[0276] ##STR52##
[0277] 1.7 g of 6-chloropurine was heated at reflux in 50 ml of
HMDS (hexamethyldisilazane) containing 50 mg of
(NH.sub.4).sub.2SO.sub.4 (ammonium sulfate) until the solution
became clear (1 hour). Excess HMDS was removed under reduced
pressure. The oily residue was dried under high vacuum for 1 hour
and then dissolved in 100 ml of dry 1,2-dichloroethane.
[0278] 2.7 g of 2-benzoyloxymethyl-5-ethoxy-1,3-oxathiolane (VIII)
was dried in a 500 ml round bottom flask by evaporation twice with
50 ml of benzene and dissolved in 200 ml of dry
1,2-dichloroethane.
[0279] The solution of silylated 6-chloropurine was then
transferred into the 1,3-oxathiolane solution through a canula
under argon atmosphere. 11 ml of 1M TMS-triflate (trimethylsilyl
trifluoromethane sulfonate) was added to the reaction flask. The
mixture was heated at reflux for 5 hours, then cooled to room
temperature. The mixture was poured into 300 ml of saturated sodium
bicarbonate solution (NaHCO.sub.3 solution) while stirring. The
organic layer was collected and the aqueous phase was extracted
with CH.sub.2Cl.sub.2 (2.times.100 ml). The combined organic phase
was washed with water, dried over MgSO.sub.41 filtered and
evaporated under reduced pressure. The residue was purified and
separated on silica gel using Hexane-ethyl acetate 7:3 as eluant.
It yielded 1.05 g (28%) of the less polar product, which was
identified as alpha- or trans-isomer as a foam, and 710 mg of lower
product as beta- or cis-isomer. Total yield 46.1%; cis:trans ratio
1:1.4
[0280] trans-isomer (.alpha.-isomer): R.sub.f: 0.43 in Hexane:EtOAc
1:1
[0281] U.V.: (MeOH) Lambda max: 264.7 nm
[0282] .sup.1H-NMR .delta.(ppm in CDCl.sub.3): 8.76 (s, 1H,
C.sub.8'--H) 8.48 (s, 1H, C.sub.2'--H) 8.06 (m, 2H, aromatic) 7.56
(m, 1H, aromatic) 7.45 (m, 2H, aromatic) 6.90 (dd, 1H, C.sub.5--H,
J=5.0 Hz) 5.78 (dd, 1H, C.sub.2--H, J=6.0 Hz) 4.56 (m, 2H,
C.sub.2--CH.sub.2OCOC.sub.6H.sub.5) 3.74 (m, 2H, C.sub.4--H)
[0283] cis-isomer (beta-isomer): R.sub.f: 0:35 in Hexane:EtOAc:
1:1
[0284] U.V.: (MeOH) Lambda max 264.7 nm
[0285] .sup.1H-NMR .delta.(ppm in CDCl.sub.3): 8.72 (s, 1H,
C.sub.8--H) 8.51 (s, 1H, C.sub.2'--H) 8.00 (m, 2H, aromatic) 7.56
(m, 1H, aromatic) 7.44 (m, 2H, aromatic) 6.61 (t, 1H, C.sub.5--H,
J=4.7 Hz) 5.62 (t, 1H, C.sub.2--H, J=4.9 Hz) 4.69 (m, 2H,
C.sub.2--CH.sub.2OCOC.sub.6H.sub.5) 3.66 (m, 2H, C.sub.4--H)
Example 12
Cis-2-hydroxymethyl-5-(6'-hydroxypurin-N-9'-yl)-1,3-oxathiolane
(inosine derivative)
[0286] ##STR53##
[0287] 533 mg of
cis-2-benzoyloxymethyl-5-(6-chloropurin-N-9'-yl)-1,3-oxathiolane
was dissolved in 25 ml of methanol. 5 g of sodium hydroxide (NaOH)
and 3 ml of water were added into the solution. The mixture was
heated at reflux for 5 hours and cooled to room temperature. The
solution was then diluted with 100 ml of water, neutralized with
pyridinium resin and filtered. The resin residue was washed with
100 ml of methanol. The combined filtrate was evaporated under
reduced pressure. The residue was purified on silica gel using
CH.sub.2Cl.sub.2:MeOH 4:1 as eluant. It yielded 183 mg (51%) of
pure product, which was identified as inosine derivative.
[0288] m.p.: 208-210.degree. C.; R.sub.f: 0.27 in EtOAc:MeOH
4:1
[0289] U.V.: (MeOH) Lambda max: 246 nm
[0290] .sup.1H-NMR: .delta.(ppm in DMSO-d.sub.6) 12.42 (s, 1H,
--NH, D.sub.2O exchange) 8.36 (s, 1H, C.sub.8'--H) 8.07 (s, 1H,
C.sub.2'--H) 6.37 (t, 1H, C.sub.5--H, J=5.1 Hz) 5.29 (t, 1H, --OH,
J=6.0 Hz, D.sub.2O exchange) 5.24 (t, 1H, C.sub.2--H, J=4.9 Hz)
3.63 (m, 4H, 2H from C.sub.4--H and 2H from CH.sub.2--OH)
Example 13
Cis- and
trans-2-benzoyloxymethyl-5-(uracil-N-1'-yl)-1,3-oxathiolane
[0291] ##STR54##
[0292] 760 mg of uracil was heated at reflux in 30 ml of HMDS in
the presence of 50 mg (NH.sub.4).sub.2SO.sub.4 until the solution
became clear. The mixture was evaporated under reduced pressure.
The residue was dried under high vacuum for 1 hour and dissolved in
100 ml of dry 1,2-dichloroethane.
[0293] 1.5 g of 2-benzoyloxymethyl-5-ethoxy-1,3-oxathiolane was
dried by evaporation twice with 50 ml of benzene in a 500 ml round
bottom flask and dissolved in 150 ml of dry 1,2-dichloroethane.
[0294] The silyated uracil solution was transferred into the
oxathiolane solution through a canula under argon atmosphere and
1.5 ml of TMS-Triflate in 20 ml of 1,2-dichloroethane was added.
The reaction mixture was heated at reflux under argon atmosphere
for 48 hours, cooled to room temperature and poured into 300 ml of
saturated aqueous NaHCO.sub.3 solution. The organic layer was
collected. The aqueous phase was extracted twice with
CH.sub.2Cl.sub.2 (2.times.100 ml). The combined organic layer was
washed with water (2.times.200 ml), once with NaCl solution
(1.times.150 ml) and dried over MgSO.sub.4. After filtration,
solvent was removed by evaporation in vacuum and the residue was
purified on silica gel using Hexane:EtOAc 1:1 as eluant. It yielded
594 mg (32%) of pure product.
[0295] The product was shown as only one spot in the TLC. However
the .sup.1H-NMR spectrum indicated the presence of two isomers
cis:trans in a ratio of 1:1.2 and which were not separated at this
stage.
[0296] R.sub.f: 0.35 in Hexane:EtoAc 3:7
[0297] U.V.: (MeOH) Lambda max: 261 nm
[0298] .sup.1H-NMR .delta.(ppm in CDCl.sub.3) 8.88 (broad s, 1H,
N.sub.3--H) 8.05 (m, 2H, aromatic) 7.71 (d, 1H, C.sub.6'--H cis,
J=8.2 Hz) 7.57 (m, 1H, aromatic) 7.45 (m, 3H, aromatic and
N.sub.3'--H) 6.55 (dd, 1H, C.sub.5--H trans, J=2.4 and 5.4 Hz) 6.35
(dd, 1H, C.sub.5--H cis, J=4.1 and 5.6 Hz) 5.79 (t, 1H, C.sub.2--H
trans, J=5.4 Hz) 5.73 (d, 1H, C.sub.5'-H trans, J=8.2 Hz) 5.57 (d,
1H, C.sub.5'--H cis, J=8.2 Hz) 5.46 (t, 1H, C.sub.2--H cis, J=3.9
Hz) 4.73 (d, 2H, --CH.sub.2O--COC.sub.6H.sub.5) 4.45 (t, 2H,
--CH.sub.2OCOC.sub.6H.sub.5) 3.57 (m, 1H, C.sub.4--H) 3.17 (m, 1H,
C.sub.4--H)
Example 14
Cis-2-hydroxymethyl-5-(uracil-N-1'-yl)-1,3-oxathiolane
[0299] ##STR55##
[0300] 300 mg of a mixture cis- and
trans-2-benzoyloxymethyl-5-(uracil-N-1'-yl)-1,3-oxathiolanes was
dissolved in 75 ml of methanolic ammonia. The mixture was stirred
at room temperature overnight. The solution was evaporated by
dryness. The residue was purified and the two isomers were
separated on silica gel using EtOAc:MeOH 98:2 as eluant.
[0301] The top product was isolated as a solid product and was
identified as cis-isomer.
[0302] Cis-isomer: m.p. 162-164.degree. C.; R.sub.f: 0.57 in
EtoAc:MeOH 95:5
[0303] U.V.: (MeOH) Lambda max: 261.4 nm
[0304] .sup.1H-NMR .delta.(ppm in DMSO-d.sub.6): 11.36 (s,1H,
N.sub.3'--H); 7.88 (d, 1H, C.sub.6'--H, J=8.1 Hz); 6.18 (t, 1H,
C.sub.5--H, J=4.8 Hz); 5.62 (d, 1H, C.sub.5'--H, J=8.1 Hz); 5.33
(t, 1H, C.sub.2--H, J=5.7 Hz); 5.17 (t, 1H, --OH, D.sub.2O
exchange) 3.72 (t, 2H, C.sub.2--CH.sub.2 OH, J=4.6 Hz) 3.41 (dd,
1H, C.sub.4--H, J=5.7 and 12 Hz) 3.20 (dd, 1H, C.sub.4--H, J=4.6
and 9.9 Hz)
Example 15
Cis- and
trans-2-benzoyloxymethyl-5-(thymin-N-1'-yl)-1,3-oxathiolane
[0305] ##STR56##
[0306] 1.7 g of thymine was heated at reflux in 50 ml of HMDS
containing 50 mg of (NH.sub.4).sub.2SO.sub.4 until the solution
became clear. The mixture was evaporated under reduced pressure.
The residue was dried under high vacuum for 1 hour and dissolved in
150 ml of 1,2-dichloroethane.
[0307] 3 g of 2-benzoyloxymethyl-5-ethoxy-1,3-oxathiolane was dried
by evaporation twice with 75 ml of benzene and dissolved in 150 ml
of dry 1,2-dichloroethane.
[0308] The silylated thymine solution was transferred into the
oxathiolane through a canula under argon atmosphere. 3.3 ml of
TMS-Triflate (trimethylsilyl-triflate) in 30 ml of dry
1,2-dichloroethane was introduced into the reaction mixture through
a canula under argon atmosphere. The solution was heated at reflux
under argon atmosphere for 36 hours, cooled to room temperature and
poured into 300 ml of saturated aqueous NaHCO.sub.3 solution. The
organic layer was collected and the aqueous phase was extracted
twice with methylene chloride (2.times.100 ml). The combined
organic phase was washed twice with water (2.times.200 ml), once
with NaCl solution (1.times.150 ml) and dried over MgSO.sub.4. The
solution was filtered. The filtrate was evaporated in vacuum. The
residue was purified on silica gel using Hexane:EtOAc 1:1 as
eluant. It yielded 1.3 g (35%) of pure product.
[0309] The product was shown as only one spot on TLC but the
.sup.1H-NMR spectrum indicated the presence of the two isomers cis
and trans in a ratio of 1:1.2.
[0310] R.sub.f: 0.30 in Hexane:EtOAc 2:3
[0311] U.V.: (MeOH) Lambda max: 266 nm
[0312] .sup.1H-NMR .delta.(ppm in CDCl.sub.3): 8.60 (broad
singlett, N.sub.3'--H) 8.06 (m, 2H, aromatic) 7.59 (m, 1H,
aromatic) 7.49 (m, 2H, aromatic) 7.38 (d, 1H, C.sub.6'--H-cis,
J=1.3 Hz) 7.28 (d, 1H, C.sub.6'--H-trans, J=1.3 Hz) 6.55 (dd, 1H,
C.sub.5--H-trans isomer, J=3.1 and 5.6 Hz) 6.38 (t, 1H,
C.sub.5--H-cis isomer, J=5.5 Hz) 5.78 (dd, 1H, C.sub.2--H-trans,
J=4.4 and 6.4 Hz) 5.46 (t, 1H, C.sub.2--H-cis-isomer, J=4.3 Hz)
4.69 (d, 2H, C.sub.2--CH.sub.2OCOC.sub.6H.sub.5, J=4.2 Hz) 4.45 (m,
2H, C.sub.2--CH.sub.2OCOC.sub.6H.sub.5) 3.58 (m, 1H, C.sub.4--H)
3.13 (m, 1H, C.sub.4--H) 1.93 (d, 1H, C.sub.5'--CH.sub.3-trans
isomer, J=1.2 Hz) 1.78 (d, 1H, C.sub.5'--CH.sub.2-cis isomers,
J=1.2 Hz)
Example 16
Cis-2-hydroxymethyl-5-(thymin-N-1'-yl)-1,3-oxathiolane
[0313] ##STR57##
[0314] 500 mg of a mixture cis- and
trans-2-benzoyloxymethyl-5-(thymin-N-1'-yl)-1,3-oxathiolanes (XLIX)
was dissolved in 100 ml of saturated methanolic ammonia. The
mixture was stirred at room temperature overnight (18 hours). The
mixture was then evaporated to dryness under reduced pressure. The
residue was separated on silica gel using EtOAc:MeOH 98:2 as
eluant.
[0315] The less polar product was identified as cis-isomer mp:
167-168.degree. C.; R.sub.f: 0.66 in EtOAc:MeOH 95:5
[0316] U.V.: (MeOH) Lambda max: 266 nm
[0317] .sup.1H-NMR .delta.(ppm in DMSO-d.sub.6) 11.38 (s, 1H,
N.sub.3'--H) 7.73 (d, 1H, C.sub.6'--H, J=1.1 Hz) 6.16 (t, 1H,
C.sub.5--H, J=5.5 Hz) 5.31 (t, 1H, C.sub.2--H, J=5.9 Hz) 5.14 (t,
1H, OH, D.sub.2O exchange) 3.70 (t, 2H, C.sub.2--CH.sub.2OH, J=5.1
Hz) 3.36 (dd, 1H, C.sub.4--H, J=5.7 and 1.7 Hz) 3.16 (dd, 1H,
C.sub.4--H, J=5.5 and 11.7 Hz) 1.75 (d, 3H, C.sub.5'--CH.sub.3,
J=1.7 Hz)
Example 17
Cis- and
trans-2-benzoyloxymethyl-5-(N.sub.4'-acetyl-5'-fluoro-cytosin-1'--
yl)-1,3-oxathiolane
[0318] ##STR58##
[0319] 5-Fluorocytosine (4.30 g, 33.3 mmol), hexamethyldisilazane
(25 ml) and ammonium sulfate (120 mg) were boiled under reflux
until the cytosine dissolved (3 hours) and then further refluxed
for 2 hours. The hexamethyldisilazane is evaporated in vacuo and
toluene (100 ml) was added to the residue to co-evaporate the
solvents. The resulting solution,
bis(trimethylsilyl)-fluoro-cytosine in dichloromethane (40 ml) was
added under argon to a solution of
2-benzoyloxymethyl-5-acetoxy-1,3-oxathiolane (8.537 g, 30.3 mmol)
in dry dichloromethane (100 ml) and molecular sieves (4A, 2 g)
previously prepared under argon and cooled at 0.degree. C. for 20
minutes. [(Trifluoromethane-sulfonyl)oxy]trimethyl silane (6 ml, 31
mmol) was added to this mixture at 0.degree. C. and the resulting
solution was stirred at 25.degree. C. for approximately 18 hours.
The reaction mixture was then treated with 300 ml of saturated
solution of sodium bicarbonate and stirred at room temperature for
2 hours. The filtrate was shaken two times with 300 ml of brine and
one time with distilled water. The organic layer was dried over
magnesium sulfate, filtered and evaporated to dryness. This
afforded a crude 5-fluoro-cytosine derivative (10.1 g). R.sub.f:
0.57 (EtOAc:MeOH 9:1)
[0320] This residue was acetylated in the next step without further
purification. The crude material was dissolved in dry
dichloromethane (120 ml) in a 500 ml round bottom flask under
argon. Triethylamine (12.7 ml, 91.1 mmol) and dimethyl
aminopyridine (111 mg, 0.9 mmol) were added to the solution. The
flask was then immersed in an ice bath for 1 hour under argon.
Acetic anhydride (4.3 ml, 45 mmol), distilled over sodium acetate,
was syringed into the cooled flask. The mixture was stirred
overnight and then carefully decanted into an erlenmeyer flask
containing saturated sodium bicarbonate solution. The product was
then washed with distilled water followed by brine solution. The
methylene chloride portions were dried and evaporated under high
vacuum to dryness, yielding an acetylated .alpha./.beta. mixture as
a colorless foam, weighing 9.6 g after drying. Flash chromatography
of this material using ethylacetate:methanol (9:1) afforded 3.1 g,
7.8 mmol (46%) pure trans-(LI) and 3.5 g, 8.9 mmol (30%) pure
cis-(LI).
[0321] trans-isomer: R.sub.f: 0.65 in ethyl acetate:methanol
9:1
[0322] U.V.: (MeOH) Lambda max: 309 nm
[0323] .sup.1H-NMR .delta.(ppm in CDCl.sub.3) 8.77 (b, 1H;
C.sub.4'--NH--Ac) 8.06 (m, 2H; aromatic) 7.70 (d, 1H; C.sub.6'--H,
J.sub.6,F=6.3 Hz) 7.62 (m, 1H; aromatic) 7.49 (m, 2H; aromatic)
6.51 (dd, 1H; C.sub.5--H) 5.91 (dd, 1H; C.sub.2--H) 4.48 (dd, 2H;
C.sub.2--CH.sub.2OCOC.sub.6H.sub.5) 3.66 (dd, 1H; C.sub.4--H) 3.34
(dd, 1H; C.sub.4--H) 2.56 (s, 3H; NH--COCH.sub.3)
[0324] cis-isomer: R.sub.f: 0.58 in ethyl acetate:methanol 9:1
[0325] U.V.: (MeOH) Lambda max: 309 nm
[0326] .sup.1H-NMR .delta.(ppm in CDCl.sub.3) 8.72 (b, 1H;
C.sub.4'--NH--Ac) 8.06 (m, 2H; aromatic) 7.87 (d, 1H; C.sub.6'--H,
J.sub.6,F=6.2 Hz) 7.60 (m, 1H; aromatic) 7.49 (m, 2H; aromatic)
6.32 (dd, 1H; C.sub.5--H) 5.47 (dd, 1H; C.sub.2--H) 4.73 (dd, 2H;
C.sub.2--CH.sub.2OCOC.sub.6H.sub.5) 3.62 (dd, 1H; C.sub.4--H) 3.19
(dd, 1H; C.sub.4--H) 2.55 (s, 3H; NH COCH.sub.3)
Example 18
Cis- and
trans-hydroxymethyl-5-(5'-fluorocytosin-1'-yl)-1,3-oxathiolane
[0327] ##STR59##
[0328] 1.0 g (2.54 mmol) of
trans-2-benzoyloxymethyl-5-(N.sub.4'-acetyl-5'-fluoro-cytosin-1'-yl)-1,3--
oxathiolane was stirred in 25 ml of methanolic ammonia at 0.degree.
C. for 1 hour and then overnight at room temperature. The mixture
was evaporated under reduced pressure. The residue was triturated
twice (2.times.30 ml) with anhydrous ether. The solid residue was
recrystallized in absolute ethanol to give 484 mg (1.95 mmol, 77%)
of desired product trans-(LII): m.p. 219-221.degree. C.;
R.sub.f=0.21 in ethyl acetate: methanol (9:1), which was identified
by .sup.1H, .sup.13C-NMR and U.V. Lambda max (H.sub.2O) 280.9
nm.
[0329] 1.2 (3.05 mmol) of
cis-2-benzoyloxymethyl-5-(N.sub.4'-acetyl-5'-fluoro-cytosin-1'-yl)-1,3-ox-
athiolane was stirred in 30 ml of methanolic ammonia at 0.degree.
C. for 1 hour and then overnight at room temperature. The mixture
was evaporated under reduced pressure. The residue was triturated
twice (2.times.30 ml) with anhydrous ether. The solid residue was
recrystallized in absolute ethanol to give 655 mg (2.64 mmol, 87%)
of pure product cis-(LII): m.p. 204-206.degree. C.; R.sub.f=0.21 in
ethylacetate: methanol (9:1). The desired compound was identified
by .sup.1H, .sup.13C-NMR and U.V. Lambda max (H.sub.2O) 280.9
nm.
[0330] trans-isomer:
[0331] .sup.1H-NMR .delta.(ppm in DMSO-d.sub.6): 7.85 (d, 1H;
C.sub.6'--H, J.sub.CF=7.01 H.sub.Z) 7.83 (d, 2H;
C.sub.4'--NH.sub.2) 6.30 (dd, 1H; C.sub.5--H) 5.60 (t, 1H;
C.sub.2--H) 5.18 (t, 1H; C.sub.2--CH.sub.2--OH) 3.49 (m, 3H;
C.sub.2--CH.sub.2OH+C.sub.4H) 3.17 (dd, 1H; C.sub.4--H)
[0332] .sup.13C NMR (DMSO-d.sub.6), Varian XL 300); .delta. in ppm
TABLE-US-00001 C.sub.2' C.sub.4' C.sub.5' C.sub.6' 153.47 158.20
134.65 126.24 (.sup.2J.sub.CF = 13.2 Hz) (JCF = 26.2 Hz) (.sup.2JCF
= 32.0 H.sub.z) C.sub.5 C.sub.4 C.sub.2 CH.sub.2OH 88.20 6.18 87.16
64.71
[0333] cis-isomer:
[0334] .sup.1H-NMR .delta.(ppm in DMSO-d.sub.6) 8.22 (d, 1H;
C.sub.6'--H, J.sub.CF=7.26H.sub.Z) 7.84 (d, 2H; C.sub.4'--NH.sub.2)
6.16 (t, 1H; C.sub.5--H) 5.43 (t, 1H; C.sub.2--CH.sub.2--OH) 5.19
(t, 1H; C.sub.2--H) 3.77 (m, 2H; C.sub.2--CH.sub.2OH) 3.35 (dd, 1H;
C.sub.4--H) 3.12 (dd, 1H; C.sub.4--H)
[0335] .sup.13C NMR (DMSO-d.sub.6) TABLE-US-00002 C.sub.2' C.sub.4'
C.sub.5' C.sub.6' 153.46 158.14 134.63 126.32 (.sup.2J.sub.CF =
14.0 Hz) (J.sub.CF = 24.1 Hz) (J.sub.CF = 32.5 Hz) C.sub.5 C.sub.4
C.sub.2 CH.sub.2OH 86.82 36.80 86.77 62.32
Example 19
2-chloromethyl-1,3-dioxolane-4-carboxylic acid
[0336] ##STR60##
[0337] Starting material (XXV) (40 g; prepared according to E. G.
Hallonquist and H. Hibbert, Can. Res. J. 1933, 7, 129) was treated
with pyridinium dichromate (PDC; 345 g) in dimethyl formamide (DMF;
690 ml) at 0.degree. according to the procedure of E. J. Corey and
G. Schmidt, Tetrahedron Lett., 1979, 399 and product (XXVI)
obtained as a crude mixture of cis- and trans-isomers (20 g) was
identified by its .sup.1H NMR spectrum [200 MHz, CDCl.sub.3;
tetramethyl silane (TMS) as internal reference]. .delta.(ppm):
3.6-3.8 (m,2H;CH.sub.2Cl); 4.1-4.5 (m,2H;C.sub.5H.sub.2);
4.72-4.797 (qq,1H;C.sub.4--H); 5.29-5.46 (tt,1H;C.sub.2--H).
The product was used as such in the next step.
Example 20
Cis- and
trans-2-chloromethyl-4-m-chlorobenzoyloxy-1,3-dioxolane
[0338] ##STR61##
[0339] The preceding product (XXVI) (5.26 g) was treated in
CH.sub.2Cl.sub.2 at -20.degree. with 3.6 ml of ethyl chloro-formate
in the presence of 4.5 of triethylamine. To the solution was added
8.85 g of m-chloroperbenzoic acid at room temperature according to
the procedure of D. H. R. Barton, I. H. Coates and P. G. Sammes, J.
Chem. Soc., Perkin 1, 1973, 599 to give (XXVII) as a mixture of
cis- and trans-isomers. These were separated and purified by flash
chromatography on silica gel using a mixture of hexanes and ethyl
acetate as the eluent. The isomers were identified by their .sup.1H
NMR spectra (recorded as in example 19):
[0340] trans-isomer of (XXVII): .delta.(ppm): 3.66
(q,2H;CH.sub.2--Cl); 4.36 (qq,2H;C.sub.5--H.sub.2); 5.57
(t,1H;C.sub.2--H); 6.7 (q,1H;C.sub.4--H); 7.39-8.0 (m,4H;aromatic
H);
[0341] cis-isomer of (XXVII): .delta.(ppm): 3.66 (q,2H;CH.sub.2Cl);
4.24 (qq,2H;C.sub.5--H.sub.2); 5.43 (t,1H;C.sub.2--H); 6.63
(q,1H;C.sub.4--H); 7.42-8.04 (m,4H;aromatic H).
Example 21
2-chloromethyl-4-(thymin-1'-yl)-1,3-dioxolane
[0342] ##STR62##
[0343] Reaction of the preceding compound with thymine was carried
out according to the procedure of D. S. Wise and L. B. Townsend, in
Nucleic Acid Chemistry, Eds. L. B. Townsend and R. S. Tipson, John
Wiley & Sons, Inc., New York, 1978, Part 1, pp. 413-419. The
product was a mixture of cis- and trans-isomers of (XXVIII) (37.3
mg from 131 mg of (XXVII)) which had the following .sup.1H NMR
characteristics (obtained as in example 19): .delta.(ppm): 1.93
(d,3H;5'--CH.sub.3); 3.64 and 3.85 (dd,2H;CH.sub.2Cl); 4.17-4.46
(m,2H;C.sub.5--H.sub.2); 5.26 and 5.72 (tt,1H;C.sub.2--H); 6.6 and
6.66 (qq,1H;C.sub.4--H); 7.40 and 7.49 (dd,1H;C.sub.6--H);
[0344] U.V.: (CH.sub.3OH) max. 264 nm.
Example 22
Cis- and trans-2-acetoxymethyl-4-(thymin-1'-yl)-1,3-dioxolane
[0345] ##STR63##
[0346] The preceding compound (XXVIII) (35 mg) was reacted with
anhydrous potassium acetate (70 mg) in boiling DMF (3 ml) for 4 h
to give after conventional workup a cis- and trans-mixture of
(XXIX) (25 mg). These isomers were purified and separated by flash
chromatography on silica using a mixture of hexanes and ethyl
acetate as the eluent. Their .sup.1H NMR spectra were as
follows:
[0347] trans-isomer of (XXIX): .delta.(ppm): 1.94
(d,3H;C.sub.5'--CH.sub.3); 2.12 (s,3H;CH.sub.3CO.sub.2--);
4.05-4.43 (m,4H;C.sub.2--CH.sub.2--O.sub.2CCH.sub.3 and
C.sub.5--H.sub.2); 5.65 (t,1H;C.sub.2--H); 6.31 (q,1H;C.sub.4--H);
7.14 (d,1H;C.sub.6,--H); 8.18 (m,1H;N.sub.3,--H).
[0348] cis-isomer of (XXIX): .delta.(ppm): 1.97
(d,3H;C.sub.5,CH.sub.3) 2.14 (s,3H;CH.sub.3CO--O) 4.13-4.49
(m,4H;2-CH.sub.2OCOCH.sub.3 and C.sub.5H.sub.2); 5.19
(t,1H;C.sub.2--H); 6.40 (q,1H;C.sub.4H); 7.43 (d,1H;C.sub.6,--H)
8.12 (m,1H;N.sub.3,--H).
[0349] U.V.: (CH.sub.3OH) max. 264 nm.
Example 23
Cis- and trans-2-hydroxymethyl-4-(thymin-1'-yl)-1,3-dioxolane
[0350] ##STR64##
[0351] The preceding trans- and cis-isomers of XXIX (10 mg) were
respectively treated with a catalytic amount of potassium carbonate
in methanol (5 ml) at room temperature for 5-6 h and the mixture
worked up in the usual manner and the respective products purified
by flash chromatography on silica gel using a mixture of ethyl
acetate and methanol as the eluent. The .sup.1H NMR spectrum of the
pure trans-isomer of (XXX) was as follows (in CD.sub.3COCD.sub.3 as
solvent);
[0352] trans-(XXX): .delta.(ppm): 1.87 (d,3H;C.sub.5,--CH.sub.3);
3.61 (q;2H;C.sub.2--CH.sub.2OH); 4.30 (qq,2H;C.sub.5--H.sub.2);
5.56 (t,1H;C.sub.2--H); 6.31 (q,1H;C.sub.4--H); 7.41
(d,1H;C.sub.6,H).
[0353] U.V.: (CH.sub.3OH) max. 265 nm.
[0354] cis-isomer of (XXX) (in CD.sub.3COCD.sub.3): .delta.(ppm):
1.82 (d,3H;C.sub.5,--CH.sub.3); 3.82 (q,2H;C.sub.2CH.sub.2OH); 4.24
(qq,2H;C.sub.5--H.sub.2); 5.02 (t,1H;C.sub.2--H); 6.34
(q,1H;C.sub.4--H); 7.81 (d,1H;C.sub.6,--H).
[0355] U.V.: (CH.sub.3OH) max. 264 nm.
Example 24
2-benzoyloxy methyl-4-hydroxymethyl-1,3-dioxolane
[0356] ##STR65##
[0357] Starting material XXV (41.6) was treated with potassium
benzoate (65.56 g) in boiling dimethyl formamide containing 100 mg
of 18-crown-6 for 24 h after which time the mixture was worked up
in the usual manner and the product (51.02 g) characterized by its
.sup.1H NMR spectrum (CDCl.sub.3;TMS): .delta.(ppm): 3.5-4.8
(m7H;C.sub.5--H.sub.2;C.sub.2--CH.sub.2OCOC.sub.6H.sub.5,C.sub.4--CH.sub.-
2OH and C.sub.2--H); 5.05 and 5.16 (tt,1H;C.sub.4--H); 7.27-8.10
(m,5H; aromatic H).
Similar results were obtained using potassium acetate instead of
potassium benzoate.
Example 25
2-benzoyloxymethyl-1,3-dioxolane-4-carboxylic acid
[0358] ##STR66##
[0359] The preceding compound (XXXI) (51.02 g) was treated at 0
with pyridinium dichromate (282.5 g) in dimethyl formamide (565 ml)
and the mixture worked up in the usual manner to give 35 g of crude
(XXXII) which was used as such in the next example.
Example 26
Cis- and
trans-2-benzoyloxymethyl-4-(m-chlorobenzoyloxy)-1,3-dioxolane
[0360] ##STR67##
[0361] A 10 g portion of crude (XXXII) was treated with 6.03 ml of
ethyl chloroformate in the presence of 8.6 ml of triethylamine
followed by the addition of 16.81 g of m.chloroperbenzoic acid
exactly as described in example 20 for the case of the preparation
of intermediate (XXVII). The isomers of product (XXXIII) thus
obtained were purified by flash chromatogaphy on silica gel using a
mixture of hexanes and ethyl acetate as the eluent. They were
characterized by their .sup.1H NMR spectra (CDCl.sub.3);
[0362] trans-isomer of (XXXIII): .delta.(ppm): 4.29
(qq,2H;C.sub.5--H.sub.2); 4.49
(d,2H;C.sub.2--CH.sub.2OCOC.sub.6H.sub.5); 5.66 (t,1H;C.sub.2--H);
6.70 (q,1H;C.sub.4--H); 7.27-8.10 (m,9H; aromatic)
[0363] cis-isomer of (XXXIII): .delta.(ppm): 4.27
(qq,2H;C.sub.5--H.sub.2); 4.51 (d,2H;C.sub.2--CHOCOC.sub.6H.sub.5);
5.51 (t,1H;C.sub.2--H); 6.59 (d,1H;C.sub.4--H); 7.26-8.09 (m,9H;
aromatic).
Example 27
2-benzoyloxymethyl-4-(cytosin-1'-yl)-1,3-dioxolane
[0364] ##STR68##
[0365] Following the procedure described by T. Ueda and S. I.
Watanabe, Chem. Pharm. Bull. (Japan), 1985, 33, 3689-3695 and by G.
Gosselin, M. C. Bergogne, J. DeRudder, E. DeClercq and J. L.
Imbach, J. Med., Chem, 1987, 30, 982-991, cytosine (139 mg) and
either isomer of the preceding compound (XXXIII) (363 mg) yielded a
mixture of cis- and trans-isomers (390 mg) (XXXIV) which were used
as such in the following step.
Example 28
Cis- and
trans-2-benzoyloxymethyl-4-(N-acetylcytosin-1'-yl)-1,3-dioxolane
[0366] ##STR69##
[0367] Treatment of cis- and trans-(XXXIV) with excess acetic
anhydride in pyridine at room temperature yielded after work up in
the conventional manner, a mixture of the cis- and trans-isomers of
(XXXV) which were separated and purified by flash chromatography on
silica gel using a mixture of hexanes and ethyl acetate as the
eluent. They were characterized by their .sup.1H NMR spectra
(CDCl.sub.3):
[0368] trans-isomer of (XXXV): .delta.(ppm): 2.15
(s,3H;C.sub.4,--NH--COCH.sub.3); 4.16 and 4.46
(m,4H;C.sub.5--H.sub.2 and C.sub.2--CH.sub.2OCOC.sub.6--H.sub.5);
5.96 (t,1H;C.sub.2--H); 6.24 (q,1H;C.sub.4--H); 7.55-8.09
(m,5H;aromatic); 8.15 (d,1H;C.sub.6,--H)
[0369] cis-isomer of (XXXV): .delta.(ppm): 2.15
(s,3H;C.sub.4--NH--COCH.sub.3); 4.26 and 4.56
(m,4H;C.sub.5--H.sub.2 and C.sub.2--CH.sub.2OCOC.sub.6--H.sub.5);
5.35 (t,1H;C.sub.4--H); 6.25 (q,1H;C.sub.4--H); 7.18
(d,1H;C.sub.5,--H); 7.58-8.04 (m,5H; aromatic) 8.17
(d,1H;C.sub.6--H).
Example 29
Cis- and trans-2-hydroxymethyl-4-(cytosin-1'-yl)-1,3-dioxolane
[0370] ##STR70##
[0371] Each of the preceding isomers of (XXXV) (25 mg) was treated
with potassium carbonate (20 mg) in methanol at room temperature
for several hours and the mixtures worked in the usual manner to
yield each isomer of (XXIV) which were purified by chromatography
on silica gel using a mixture of ethyl acetate and methanol an
eluent. They were crystallized from methanol and characterized by
their respective .sup.1H NMR spectra (CD.sub.3COCD.sub.3):
[0372] trans-isomer of (XXXVI): m.p. 179.180.degree. .delta.(ppm):
3.62 (q,2H;C.sub.2--CH.sub.2OH); 4.21 (qq,2H;C.sub.5--H.sub.2);
5.50 (t,1H;C.sub.2--H); 5.93 (d,1H;C.sub.5,--H,J=7.5 Hz); 6.18
(q,1H;C.sub.4--H); 7.66 (d,1H;C.sub.6,--H,J=7.5 Hz).
[0373] U.V.: (CH.sub.3OH) max. 271 nm.
[0374] cis-isomer of (XXXVI): m.p. 173-174.degree. .delta.(ppm):
3.82 and 4.15 (m,4H;C.sub.5--H.sub.2 and C.sub.2--CH.sub.2OH); 5.04
(t,1H;C.sub.2--H); 5.83 (d,1H;C.sub.5,--H); 6.23 (q,1H;C.sub.4--H);
8.05 (d,1H;C.sub.6H);
[0375] U.V.: (CH.sub.3OH) max. 270 nm.
Example 30
Cis- and
trans-2-benzoyloxymethyl-4-(adenin-9'-yl)-1,3-dioxolane
[0376] ##STR71##
[0377] Following the same procedure as in example 27, adenine (135
mg) was coupled with either isomer of intermediate XXXIII (545 mg)
in dimethylformamide at 120' in the presence of trimethylsilyl
triflate (0.45 ml) and the mixture worked up in the usual manner to
yield a mixture of cis- and trans-isomers of (XXXVII) (540 mg)
which were purified and separated by chromatography on silica gel
using a mixture of hexanes and ethyl and acetate as the eluent.
They were characterized by their respective .sup.1H NMR spectra
(CDCl.sub.3):
[0378] trans-isomer of (XXXVII): .delta.(ppm): 4.5 and 4.59
(m,4H;C.sub.5--H.sub.2 and C.sub.2--CH.sub.2OCOC.sub.6H.sub.5);
6.00 (t,1H;C.sub.2--H); 6.65 (q,1H;C.sub.4--H) 6.75
(m,2H;C.sub.6,H.sub.2); 7.68-8.21 (m,5H;aromatic); 8.36
(s,1H;C.sub.2--H) 8.37 (s,1H;C.sub.8,--H)
[0379] cis-isomer of (XXXVII): .delta.(ppm): 4.62
(d,2H;C.sub.2--CH.sub.2OCOC.sub.6H.sub.5); 4.65
(qq,2H;C.sub.5--H.sub.2); 5.52 (t,1H;C.sub.2--H); 6.59
(q,1H;C.sub.4--H); 6.85 (m,2H;C.sub.6,--NH.sub.2); 6.96-7.71
(m,5H;aromatic); 7.66 (d,2H;C.sub.2'--H and C.sub.8, --H).
Example 31
Cis- and trans-2-hydroxymethyl-4-(adenin-9'-yl)-1,3dioxolane
[0380] ##STR72##
[0381] Each isomer of the preceding compound (XXXVII) was treated
with potassium carbonate in methanol at room temperature by the
same procedure described in example 23 and each product purified by
column chromatography on silica gel using a mixture of ethyl
acetate and methanol as the eluent. The isomers were further
purified by crystallization from methanol and characterized by
their .sup.1N NMR spectra (CD.sub.3SOCD.sub.3):
[0382] trans-isomer of (XXXVIII): .delta.(ppm): 3.50
(d,2H;C.sub.2--CH.sub.2OH); 4.70 (m,2HC.sub.5--H.sub.2); 5.52
(t,1H;C.sub.2--H); 6.44 (q,1H,C.sub.4--H); 8.18 (s,1H;C.sub.2,--H);
8.31 (s,1H;C.sub.8,--H).
[0383] U.V.: (CH.sub.3OH) max. 269 nm.
[0384] cis-isomer of (XXXVIII): .delta.(ppm): 4.63
(d,2H;C.sub.2--CH.sub.2OH); 4.29 (qq,2H;C.sub.5--H.sub.2); 5.08
(t,1H;C.sub.2--H); 6.43 (q,1H;C.sub.4--H); 8.18 (s,1H;C.sub.2--H);
8.36(s,1H;C.sub.8,--H).
[0385] U.V.: (CH.sub.3OH) max. 269 nm.
Example 32
Cis- and
trans-2-benzoyloxymethyl-4-(2'-amino-6'-chloro-purin-9'-yl)-1,3-d-
ioxolane
[0386] ##STR73##
[0387] A solution of 2-amino-6-chloropurine (600 mg; 3.54 mmol) in
20 ml of hexamethyldisilazane (HMDS) containing 0.5 ml of
trimethylsilyl chloride (TMS-Cl) was heated under reflux for 3 h
after which time the mixture was evaporated to dryness in vacuo.
The residue was dissolved in 75 ml of dichloroethane containing 910
mg of compound (XXXIII) and 0.6 ml of trimethylsilyl triflate
(TMS-T.sub.f) added. After refluxing under argon for 4 h, the
mixture was collected, 2 g of solid NaHCO.sub.3 added followed by
50 ml of saturated aqueous NaHCO.sub.3. The organic layer was
collected and after work-up in the usual manner, crude (XXVII) was
obtained as an oil which was purified and separated into its isomer
by chromatography on silica gel using hexane-ethyl acetate (3:7) as
the eluent to give 230 mg of pure trans- and 250 mg or pure
cis-isomer as colorless foams. They were characterized by their
.sub.1H NMR spectra (CDCl.sub.3):
[0388] trans-isomer of (XXXIX)
[0389] R.sub.f:0.40; hexane-EtOAc 3:7 .delta.(ppm): 4.45-4.52
(m,4H;C.sub.5--H.sub.2,C.sub.2--CH.sub.2OCOC.sub.6H.sub.5); 5.16
(b,2H;C.sub.2,--NH.sub.2); 5.83 (t,1H;C.sub.2--H,J=3.8 Hz); 6.39
(dd,1H;C.sub.4--H); 7.41-7.58 (m,3H;aromatic); 7.92
(s,1H;C.sub.8,--H); 8.06 (d,2H;aromatic,J=7 Hz).
[0390] U.V.: (CH.sub.3OH) max. 312 nm.
cis-isomer of (XXXIX):
[0391] R.sub.f:0.26, hexane-EtOAc 3:7 .delta.(ppm): 4.25-4.33
(dd,1H;C.sub.5--H,J=5.43 Hz); 4.59-4.64 (m,3H;C.sub.5--H and
C.sub.2--CH.sub.2--OCOC.sub.6H.sub.5); 5.17
(b,2H;C.sub.2,--NH.sub.2); 5.42 (t,1H;C.sub.2--H,J=3.50 Hz);
6.33-6.53 (dd,1H;C.sub.4--H); 7.38-7.57 (m,3H;aromatic); 7.93-7.98
(d,2H;aromatic); 8.00 (s,1H;C.sub.8,--H).
[0392] U.V.: (CH.sub.3OH) max. 312 nm.
Example 33
Cis- and
trans-2-hydroxymethyl-4-(2'-amino-6'-chloropurin-9'-yl)-1,3-dioxo-
lane
[0393] ##STR74##
[0394] The preceding trans-isomer of (XXXIX) (180 mg) was dissolved
in 30 ml of methanol, the solution cooled to 0.degree. and dry
ammonia bubbled through for 15 min. After stirring at room
temperature for 15 h, the solvent was removed in vacuo and the
residue crystallized from ether. After recrystallization from
ethanol-ether, 98 mg of pure trans-(XL), m.p. 155-156.degree., was
obtained (R.sub.f: 0.23, EtOAc). It was characterized by .sup.1H
NMR (DMSO-d.sub.6):
[0395] trans-(XL): .delta.(ppm): 3.44-3.49
(m,2H;C.sub.2--CH.sub.2OH); 4.37-4.45 (m,2H;C.sub.5--H.sub.2); 5.01
(t,1H;C.sub.5--CH.sub.2OH,J=6.2 Hz); 5.46 (t,1H;C.sub.2--H,J=3.6
Hz); 6.27-6.32 (dd,1H;C.sub.4--H,J=4,1 Hz); 7.00
(b,2H;C.sub.2,--NH.sub.2); 8.26 (s,1H;C.sub.8,--H).
[0396] U.V.: (CH.sub.3OH) max. 247 and 308 nm.
[0397] The cis-isomer of (XL) was obtained in similar yield from
the cis-isomer of (XXXIX) by the same preceding procedure. After
recrystallization from ethanol-ether, the pure product had m.p.
145-147.degree. (R.sub.f:0.24, EtoAc). It was characterized by
.sup.1H NMR (DMSO-d.sub.6): cis-(XL): .delta.(ppm): 3.54-3.59
(m,2H;C.sub.2--CH.sub.2OH); 4.12-4.19 (dd,1H;C.sub.5--H,J=5.3 Hz
and 9.8 Hz); 4.48-4.53 (d,1H;C.sub.5--H,J=9.8 Hz); 5.01
(t,1H;C.sub.2--H,J=2.8 Hz); 5.09 (t,1H;C.sub.2--CH.sub.2--OH,J=6.0
Hz); 6.24 (d,1H;C.sub.4--H,J=5.1 Hz); 6.96
(b,2H;C.sub.2--NH.sub.2); 8.23 (s,1H;C.sub.8,--H).
[0398] U.V.: (CH.sub.3OH) max. 247 and 308 nm.
Example 34
Cis- and
trans-2-hydroxymethyl-4-2'-amino-purin-9'-yl)-1,3-dioxolane
[0399] ##STR75##
[0400] The preceding trans-isomer of (XL) (50 mg) was submitted to
hydrogenation conditions under 50 psi of hydrogen over 10% Pd/C (30
mg) in 30 ml of ethanol containing 0.5 ml of triethylamine. After 3
h of shaking, the mixture was worked up in the usual manner to
yield a solid which was recrystallized from ethanol-ether to give
36 mg of pure trans-(XLI), m.p. 153-155.degree., R.sub.f:0.25
(EtOAc: MeOH 85:15). It was characterized by .sup.1H NMR
(DMSO-d.sub.6): trans-(XLI): .delta.(ppm): 3.44-3.49
(m,2H;C.sub.2--CH.sub.2OH); 4.38-4.44 (m,2H;C.sub.5--H.sub.2); 4.99
(t,1H;C.sub.2--CH.sub.2--OH,J=6.1 Hz); 5.45 (t,1H;C.sub.2--H,J=3.6
Hz); 6.29-6.34 (dd,1H;C.sub.4--H); 6.59 (b,2H;C.sub.2,--NH.sub.2);
8.19 (s,1H;C.sub.8,--H); 8.59 (s,1H;C.sub.6,--H).
[0401] The cis-isomer of (XLI) was obtained in similar yield from
the cis-isomer of (XL) by the same preceding procedure. After
recrystallization from ethanol-ether, the pure product had m.p.
145-148.degree., R.sub.f: 0.25 (EtOAc:MeOH 85:15). It was
characterized by .sup.1H NMR (DMSO-d.sub.6):
[0402] cis-(XLI): .delta.(ppm): 3.55-3.60
(dd,2H;C.sub.2--CH.sub.2H,J=2.10 and 6.1 Hz); 4.14-4.22
(dd,1H;C.sub.5--H,J=5.4 and 9.7 Hz); 4.47-4.53
(dd,1H;C.sub.5--H,J=1.38 and 9.7 Hz); 5.02 (t,1H;C.sub.2--H,J=3
Hz); 5.11 (t,1H;C.sub.2--CH.sub.2OH,J=7.2 Hz); 6.58
(b,2H;C.sub.2--NH.sub.2); 8.19 (s,1H;C.sub.8,--H); 8.57
(s,1H;C.sub.6,--H)
[0403] U.V.: (CH.sub.3OH) max. 255, 308 nm.
Example 35
Cis- and
trans-2-hydroxymethyl-4-(2',6'-diamino-purin-9'-yl)-1,3-dioxolane
[0404] ##STR76##
[0405] The above compound trans-(XXXIX) (200 mg) was dissolved in
30 ml of methanol saturated at 0 with dry ammonia and the solution
heated in a steel bomb to 105-110.degree. for 16 h. The solution
was evaporated to dryness and the residue purified by
chromatography on silica gel using chloroform-methanol 4:1 as the
eluent to give 101 mg of product which was recrystallized from
methanol-ether to yield pure trans-(XLII), m.p. 165-168.degree.,
R.sub.f:0.30(CHCl.sub.3;CH.sub.3OH 4:1). It was characterized by
.sup.1H NMR (DMSO-d.sub.6): trans-(XLII): .delta.(ppm): 3.43-3.48
(m,2H;C.sub.2--CH.sub.2OH); 4.34-4.49 (m,2H;C.sub.5--H.sub.2); 4.97
(t,1H;C.sub.2--CH.sub.2OH); 5.42 (t,1H;C.sub.2--H) 5.82
(b,2H;C.sub.2,- or C.sub.6,--NH.sub.2); 6.18-6.23
(dd,1H;C.sub.4--H); 6.72 (b,2H;C.sub.2,- or C.sub.6,--NH.sub.2);
7.84 (s,1H;C.sub.8,--H).
[0406] U.V.: (CH.sub.3OH) max. 255,280 nm.
[0407] The cis-isomer of (XLII) was obtained by the same preceding
procedure from compound cis-(XXXIX). After recrystallization from
methanol-ether, pure cis-(XLII), m.p. 180-182.degree.,
R.sub.f:0.32(CHCl.sub.3--CH.sub.3OH 4:1) was obtained in a similar
yield. It was characterized by
[0408] .sup.1H NMR (DMSO-d.sub.6): cis-(XLII): .delta.(ppm):
3.56-3.58 (d,2H;C.sub.2--CH.sub.2OH,J=4.2 Hz); 4.11-4.19
(dd,1H;C.sub.5--H,J=4.5 and 9.7 Hz); 4.38-4.44
(dd,1H;C.sub.5--H,J=1.6 and 11.2 Hz); 5.00 (t,1H;C.sub.2--H,J=3.1
Hz); 5.91 (b,2H;C.sub.2,- or C.sub.6,--NH.sub.2); 6.15-6.19
(dd,1H;C.sub.4--H); 6.84 (b,2H;C.sub.2,- or C.sub.6,--NH.sub.2);
7.86 (s,1H;C.sub.8,--H).
[0409] U.V.: (CH.sub.3OH) max. 254,279 nm.
Example 36
Cis- and trans-2-hydroxymethyl-4-(guanin-9'-yl)-1,3-dioxolane
[0410] ##STR77##
[0411] The above cis-(XL) (40 mg) was dissolved in a mixture of 15
ml of methanol, 2 ml of water and 2 g of sodium hydroxide and the
solution heated under reflux for 5 h after which time it was
diluted with 100 ml of water and excess pyridinium sulfonate resin
added. The slurry was filtered, the resin washed with water and the
combined aqueous filtrates evaporated to dryness in vacuo to leave
a residue which was taken up in 50% aqueous methanol. The solution
was treated with activated charcoal, filtered and the filtrate
evaporated to dryness in vacuo to give a solid residue that was
recrystallized from ethanol--water to yield pure cis-XLIII (27 mg)
m.p.>250.degree. decomp., R.sub.f:0.23 (CHCl.sub.3:CH.sub.3OH
7:3). It was characterized by .sup.1H NMR (DMSO-d.sub.6):
cis-(XLIII): .delta.(ppm): 3.55 (m,2H;C.sub.2CH.sub.2OH); 4.10-4.17
(dd,1H;C.sub.5--H,J=5.6 and 9.8 Hz); 4.37-4.42
(dd,1H;C.sub.5--H,J=1.4 and 9.6 Hz); 4.98 (t,1H;C.sub.2--H,J=3.2
Hz); 5.15 (b,1H;C.sub.2--CH.sub.2OH); 6.10-6.13
(dd,1H;C.sub.4--H,J=2.4 and 5.3 Hz); 6.66
(b,2H;C.sub.2,--NH.sub.2); 7.78 (s,1H;C.sub.8,--H); 11.02
(b,1H;N.sub.1,--H).
[0412] U.V.: (CH.sub.3OH) max. 252, 270(shoulder).
[0413] The isomer trans-(XLIII) was obtained in similar yield from
the above trans-(XL) by the same preceding procedure. After
recrystallization from ethanol-water, pure trans-(t),
m.p.>260.degree. (dec.), R.sub.f:0.23 (CHCl.sub.3:CH.sub.3OH
7:3) was obtained and characterized by H NMR (DMSO-d.sub.6):
trans-(XLIII): .delta.(ppm): 3.42-3.47 (m,2H;C.sub.2--CH.sub.2OH);
4.34 (d,2H;C.sub.5--H.sub.2,J=4.8 Hz); 4.99
(t,1H;C.sub.2--CH.sub.2OH); 5.40 (t,1H;C.sub.2--H,J=3.5 Hz);
6.15-6.20 (t,1H;C.sub.4--H,J=4.8 Hz); 6.49
(b,2H;C.sub.2,--NH.sub.2); 7.83 (s,1H;C.sub.8,--H); 10.64
(b,1H;N.sub.1,--H).
[0414] U.V.: (CH.sub.3OH) max. 252, 270 (shoulder)
Example 37
Tablet Formulations
[0415] A. The following formulation is prepared by wet granulation
of the ingredients with a solution of povidone in water, drying and
screening, followed by addition of magnesium stearate and
compression. TABLE-US-00003 mg/tablet (a) Active ingredient 250 (b)
Lactose B.P. 210 (c) Povidone B.P. 15 (d) Sodium Starch Glycolate
20 (e) Magnesium Stearate 5 500
[0416] B. The following formulation is prepared by direct
compression; the lactose is of the direct compression type.
TABLE-US-00004 mg/tablet Active ingredient 250 Lactose 145 Avicel
100 Magnesium Stearate 5 500
[0417] C. (Controlled Release Formulation) The formulation is
prepared by wet granulation of the ingredients (below) with a
solution of povidone in water, drying and screening followed by the
addition of magnesium stearate and compression. TABLE-US-00005
mg/tablet (a) Active ingredient 500 (b)
Hydroxypropylemethylcellulose 112 (Methocel K4M Premium) (c)
Lactose B.P. 53 (d) Povidone B.P. 28 (e) Magnesium Stearate 7
700
Example 38
Capsule Formulation
[0418] A capsule formulation is prepared by admixing the
ingredients below and filling into a two-part hard gelatin capsule.
TABLE-US-00006 mg/capsule Active ingredient 125 Lactose 72.5 Avicel
50 Magnesium Stearate 2.5 250
Example 39
Injectable Formulation
Active ingredient 0.200 g
Sodium hydroxide solution, 0.1M q.s. to a pH of about 11.
Sterile water q.s. to 10 ml.
[0419] The active ingredient is suspended in some of the water
(which may be warmed) and the pH adjusted to about 11 with a
solution of sodium hydroxide. The batch is then made up to volume
and filtered through a sterilizing grade membrane filter into a
sterile 10 ml glass vial and sealed with sterile closures and
overseas.
Example 40
suppository
[0420] TABLE-US-00007 mg/suppository Active ingredient 250 Hard
Fat, B.P. 1770 2020
[0421] One-fifth of the hard fat is melted in a steam-jacketed pan
at 45.degree. C. maximum. The active ingredient is sifted through a
200 .mu.m sieve and added to the molten base with mixing, using a
high shear stirrer, until a smooth dispersion is achieved.
Maintaining the mixture at 45.degree. C., the remaining hard fat is
added to the suspension and stirred to ensure a homogenous mix. The
entire suspension is passed through a 250 .mu.m stainless steel
screen and, with continuous stirring, is allowed to cool to
40.degree. C. At a temperature of 38.degree. C. to 40.degree. C.,
2.02 g of the mixture is filled into suitable, 2 ml plastic molds.
The suppositories are allowed to cool to room temperature.
Example 41
Antiviral Activity
[0422] All of the compounds of the preferred embodiments are novel
and some are valuable for their properties as non-toxic inhibitors
of the primary replication of HIV-1 in previously uninfected
T-lymphocytes over a prolonged period of time.
[0423] In vitro testing was conducted on several of the compounds
of this invention to determine their inhibitory properties. The
results are shown in Tables 1, 2 and 3. The concentrations reported
are .mu.g/ml in the incubation media which affect the
susceptibility of a continuous line of T-cells developed at the
Lady Davis Institute for Medical Research (Montreal) by Dr. Mark A.
Wainberg toward infection by HIV-1 following a protocol similar to
that of H. Mitsuya and S. Broder, "Inhibition of the in vitro
infectivity and cytopathic effect of human T-lymphotropic virus
type III/lymphadenopathy--associated virus (HTLV-III/LAV) by
2'3'-dideoxynucleosides", Proc. Natl. Acad. Sci. USA, 83, pp.
1911-15 (1986). Protection of the cell line from infection was
monitored by staining with monoclonal antibodies against viral
proteins in the standard manner (Table 1). In all experiments,
comparisons were made with the drug AZT as the control. In order to
confirm the results, the drug effects were monitored by measuring
reverse transcriptase (RT) activity in the U-937 line of human
monocytic cells as assayed in the usual manner with tritiated
thymidine triphosphate (TTP) (Table 2). The drug effects on cell
viability as measured by the well-know cytolytic effects of HIV-1
on the MT-4 cell line was evaluated in the accepted manner (Table
1).
Toxicity
[0424] No toxic effects were observed in the above tests.
TABLE-US-00008 TABLE 1 Inhibition of HIV-1 product by compounds of
formula (I) in MT-4 cells a) Viable cell counts (6 days in culture)
using 2 .mu.g/ml of compound Compound Cell Viability % no drug 6.47
AZT 83.6 cis-XI 87.4 trans-XI 24 cis-XII(b) 14 cis-LVI 11 cis-LIII
18 cis-XVIII 14 b) P-24 immunofluorescence Time in Culture %
Immunofluorescent Cells (Days) No Drug 2 .mu.g/ml AZT 2 .mu.g/ml
cis-XI 3 5.9 1.0 1.0 6 99 1.0 7.6 c) Reverse transcriptase assay
Time in Culture RT Activity (CPM .times. 1000)/ml (Days) No Drug 2
.mu.g/ml AZT 2 .mu.g/ml cis-XI 3 36.43 1.564 2.381 6 339.0 1.748
2.301
[0425] TABLE-US-00009 TABLE 2 Inhibition of HIV-1 production by
compounds of formula (I) in H-9 cells Reverse transcriptase assay
Time in Culture RT Activity (CPM X 1000) /ml (Days) No Drug 2
.mu.g/ml AZT 2 .mu.g/ml cis-XI 5 9.117 3.346 3.077 8 438.5 3.414
5.853 11 2550 2.918 3.560 14 2002 8.320 2.872 7 584.5 2.997 2.399
21 365.2 3.111 2.907 25 436.4 15.88 4.020 29 92.38 32.08 3.756 33
111.1 612.2 3.803 37 32.28 878.2 4.193 41 384.4 994.0 4.515 45
33.64 32.91 3.441
[0426] TABLE-US-00010 TABLE 3 Inhibition of HIV-1 production by
compounds of formula (I) in H-9 cells. RT activity (cpm) after:
Inhibitor Conc.- 8 days 12 days 26 days none -- 198,612 327,570
239,019 trans-(XXXVI) 10 .mu.M 4,608 83,462 312,478 trans-(XXXVI)
50 .mu.M 1,319 758 1,732 AZT 20 .mu.M 633 419 821 none -- 64,769
119,580 227,471 cis-(XXXVIII) 20 .mu.M 2,618 130,563 210,583
cis-(XXXVIII) 50 .mu.M 1,132 39,752 231,609 AZT 20 .mu.M 587 1,316
679
* * * * *