U.S. patent application number 15/896970 was filed with the patent office on 2018-08-16 for therapeutic compounds and methods of use thereof.
This patent application is currently assigned to GENENTECH, INC.. The applicant listed for this patent is GENENTECH, INC., XENON PHARMACEUTICALS INC.. Invention is credited to Ivan William HEMEON, Brian SAFINA, Daniel SUTHERLIN.
Application Number | 20180230079 15/896970 |
Document ID | / |
Family ID | 56851731 |
Filed Date | 2018-08-16 |
United States Patent
Application |
20180230079 |
Kind Code |
A1 |
HEMEON; Ivan William ; et
al. |
August 16, 2018 |
THERAPEUTIC COMPOUNDS AND METHODS OF USE THEREOF
Abstract
The invention provides compounds having the general formula I:
##STR00001## and pharmaceutically acceptable salts thereof, wherein
the variables R.sup.AA, n, ring A, X.sup.1, L, m, X.sup.2, R.sup.2,
R.sup.3, R.sup.4, R.sup.5, X, and R.sup.6 have the meaning as
described herein, and compositions containing such compounds and
methods for using such compounds and compositions.
Inventors: |
HEMEON; Ivan William;
(Burnaby, CA) ; SAFINA; Brian; (South San
Francisco, CA) ; SUTHERLIN; Daniel; (South San
Francisco, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GENENTECH, INC.
XENON PHARMACEUTICALS INC. |
South San Francisco
Burnaby |
CA |
US
CA |
|
|
Assignee: |
GENENTECH, INC.
South San Francisco
CA
XENON PHARMACEUTICALS INC.
Burnaby
|
Family ID: |
56851731 |
Appl. No.: |
15/896970 |
Filed: |
February 14, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/US2016/048477 |
Aug 24, 2016 |
|
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15896970 |
|
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62210891 |
Aug 27, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C07C 317/44 20130101;
C07C 62/38 20130101; C07C 313/04 20130101; C07D 211/22 20130101;
C07C 2601/14 20170501; C07C 62/34 20130101; C07C 2601/08 20170501;
C07C 69/757 20130101; A61P 29/00 20180101; A61P 25/00 20180101;
C07C 2603/74 20170501; C07C 229/48 20130101; A61P 17/04 20180101;
C07C 323/61 20130101; C07C 2601/02 20170501; C07C 2601/04
20170501 |
International
Class: |
C07C 62/38 20060101
C07C062/38; C07C 62/34 20060101 C07C062/34; C07D 211/22 20060101
C07D211/22; C07C 323/61 20060101 C07C323/61; C07C 317/44 20060101
C07C317/44; C07C 313/04 20060101 C07C313/04; C07C 229/48 20060101
C07C229/48; A61P 17/04 20060101 A61P017/04; A61P 25/00 20060101
A61P025/00; A61P 29/00 20060101 A61P029/00 |
Claims
1. A compound of Formula I: ##STR00113## or a salt thereof; wherein
each RA is independently selected from the group consisting of F,
Cl, Br, I, --CN, --OR.sup.A1, (X.sup.RA)-(6-12 membered aryl),
--(X.sup.RA)-(5-12 membered heteroaryl), and --R.sup.2, wherein
said 6-12 membered aryl and 5-12 membered heteroaryl of R.sup.AA is
optionally substituted with from 1 to 5 substitutents independently
selected from the group consisting of F, Cl, Br, I, C.sub.1-4
alkyl, C.sub.1-4 haloalkyl, and C.sub.1-4(halo)alkoxy; R.sup.A1 is
selected from the group consisting of hydrogen, C.sub.1-8 alkyl,
C.sub.2-8 alkenyl, C.sub.1-8 haloalkyl, C.sub.3-8 cycloalkyl,
phenyl and benzyl; R.sup.A2 is selected from the group consisting
of C.sub.1-8 alkyl that is optionally substituted with one or more
substituents selected from oxo (.dbd.O), fluoro, amino, C.sub.1-4
alkylamino and di(C.sub.1-4alkyl)amino; X.sup.RA is selected from
the group consisting of absent, --C(.dbd.O)--, and C.sub.1-4
alkylene; wherein any C.sub.1-4 alkylene of X.sup.RA is optionally
substituted with 1 to 3 substituents selected from the group
consisting of C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, and phenyl that
is optionally substituted with 1 to 5 substitutents selected from,
F, Cl, Br, I, --NH.sub.2, --OH, --CN, --NO.sub.2, C.sub.1-4 alkyl,
C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy, C.sub.1-4(halo)alkoxy,
C.sub.1-4 alkylamino and C.sub.1-4 dialkylamino; n is 0, 1, 2, 3,
4, 5, 6, 7, or 8; ring "A" is a 3-15 membered carbocyclyl, a 6-12
membered aryl, a 5-12 membered heteroaryl, or a 3-15 membered
heterocyclyl; X.sup.1 and X.sup.2 are each independently selected
from the group consisting of absent, --S--, --O-- and
--N(R.sup.X)-- wherein R.sup.x is H, C.sub.1-8 alkyl, or C.sub.1-8
haloalkyl, and wherein if the subscript m is 0 then one of X.sup.1
or X.sup.2 is absent; L is C.sub.1-6 alkylene, wherein L is
optionally substituted with from 1 to 3 substituents independently
selected from the group consisting of C.sub.1-4 alkyl, C.sub.1-4
alkoxy, halo, oxo (.dbd.O), and C.sub.1-4 haloalkyl; wherein any
two substituents attached to the same atom on L are optionally
combined to form a 3- to 5-membered carbocyclic ring; m is 0 or 1;
R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are each independently
selected from the group consisting of H, F, Cl, Br, I, --CN,
C.sub.1-8 alkyl, C.sub.3-8 cycloalkyl, C.sub.1-8 haloalkyl and
C.sub.1-8 alkoxy; X is selected from the group consisting of O, S,
S.dbd.O, SO.sub.2, N(R.sup.N), C.dbd.O, CH.sub.2, and C.dbd.S,
wherein R.sup.N is selected from the group consisting of H,
C.sub.1-6 alkyl and acyl; ring "B" is selected from the group
consisting of cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and
cyclooctyl, wherein ring B is optionally substituted with one or
more groups independently selected from C.sub.1-4 alkyl; and
R.sup.6 is hydrogen or C.sub.1-6 alkyl.
2. The compound of claim 1 wherein the compound of formula (I) is a
compound of formula (Ia): ##STR00114##
3. The compound of claim 1 wherein the compound of formula (I) is a
compound of formula (Ib): ##STR00115##
4. The compound of claim 1 wherein the compound of formula (I) is a
compound of formula (Ic): ##STR00116##
5. The compound of claim 1 wherein the compound of formula (I) is a
compound of formula (Id): ##STR00117##
6. The compound of claim 1 wherein the compound of formula (I) is a
compound of formula (Ie): ##STR00118##
7. The compound of claim 1 wherein the compound of formula (I) is a
compound of formula (If): ##STR00119##
8. The compound of claim 1 wherein the compound of formula (I) is a
compound of formula (Ig): ##STR00120##
9. The compound of claim 1 wherein the compound of formula (I) is a
compound of formula (Ih): ##STR00121##
10. The compound of claim 1 wherein the compound of formula (I) is
a compound of formula (Ij): ##STR00122##
11. The compound of claim 1, wherein ring "B" is selected from the
group consisting of cyclobutyl, cyclopentyl, and cyclohexyl.
12. The compound of claim 1 wherein the compound of formula (I) is
a compound of formula (Ik): ##STR00123##
13. The compound of claim 1 wherein the compound of formula (I) is
a compound of formula (Im): ##STR00124##
14. The compound of claim 1 wherein the compound of formula (I) is
a compound of formula (In): ##STR00125##
15. The compound of claim 1 wherein the compound of formula (I) is
a compound of formula (Io): ##STR00126##
16. The compound of claim 1 wherein the compound of formula (I) is
a compound of formula (Ip): ##STR00127##
17. The compound of claim 1 wherein the compound of formula (I) is
a compound of formula (Iq): ##STR00128##
18. The compound of claim 1 wherein the compound of formula (I) is
a compound of formula (Ir): ##STR00129##
19. The compound of claim 1 wherein the compound of formula (I) is
a compound of formula (Is): ##STR00130##
20-24. (canceled)
25. The compound of claim 1, wherein ring "A" is a 6-15 membered
carbocycle.
26-43. (canceled)
44. A compound selected from the group consisting of: ##STR00131##
##STR00132## ##STR00133## and salts thereof.
45. A pharmaceutical composition comprising a compound of formula I
as described in claim 1, or a pharmaceutically acceptable salt
thereof, and a pharmaceutically acceptable excipient.
46. A method of treating a disease or condition in a mammal
selected from the group consisting of pain, depression,
cardiovascular diseases, respiratory diseases, and psychiatric
diseases, and combinations thereof, wherein the method comprises
administering to the mammal in need thereof a therapeutically
effective amount of a compound of formula I as described in claim 1
or a pharmaceutically acceptable salt thereof.
47-53. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International
Application No. PCT/US2016/048477, filed 24 Aug. 2016, which claims
the benefit of U.S. Provisional Application No. 62/210,891, filed
27 Aug. 2015. The entire content of the applications referenced
above are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to organic compounds useful
for therapy in a mammal, and in particular to inhibitors of sodium
channel (e.g., NaV1.7) that are useful for treating sodium
channel-mediated diseases or conditions, such as pain, as well as
other diseases and conditions associated with the modulation of
sodium channels.
[0003] Voltage-gated sodium channels are transmembrane proteins
that initiate action potentials in nerve, muscle and other
electrically excitable cells, and are a necessary component of
normal sensation, emotions, thoughts and movements (Catterall, W.
A., Nature (2001), Vol. 409, pp. 988-990). These channels consist
of a highly processed alpha subunit that is associated with
auxiliary beta subunits. The pore-forming alpha subunit is
sufficient for channel function, but the kinetics and voltage
dependence of channel gating are in part modified by the beta
subunits (Goldin et al., Neuron (2000), Vol. 28, pp. 365-368).
Electrophysiological recording, biochemical purification, and
molecular cloning have identified ten different sodium channel
alpha subunits and four beta subunits (Yu, F. H., et al., Sci. STKE
(2004), 253; and Yu, F. H., et al., Neurosci. (2003),
20:7577-85).
[0004] The sodium channel family of proteins has been extensively
studied and shown to be involved in a number of vital body
functions. Research in this area has identified variants of the
alpha subunits that result in major changes in channel function and
activities, which can ultimately lead to major pathophysiological
conditions. The members of this family of proteins are denoted
NaV1.1 to NaV1.9.
[0005] NaV1.7 is a tetrodotoxin-sensitive voltage-gated sodium
channel encoded by the gene SCN9A. Human NaV1.7 was first cloned
from neuroendocrine cells (Klugbauer, N., et al., 1995 EMBO J., 14
(6): 1084-90.) and rat NaV1.7 was cloned from a pheochromocytoma
PC12 cell line (Toledo-Aral, J. J., et al., Proc. Natl. Acad. Sci.
USA (1997), 94:1527-1532) and from rat dorsal root ganglia
(Sangameswaran, L., et al., (1997), J. Biol. Chem., 272 (23):
14805-9). NaV1.7 is expressed primarily in the peripheral nervous
system, especially nocieptors and olfactory neurons and sympathetic
neurons. The inhibition, or blocking, of NaV1.7 has been shown to
result in analgesic activity. Knockout of NaV1.7 expression in a
subset of sensory neurons that are predominantly nociceptive
results in resistance to inflammatory pain (Nassar, et al., op.
cit.). Likewise, loss of function mutations in humans results in
congenital indifference to pain (CIP), in which the individuals are
resistant to both inflammatory and neuropathic pain (Cox, J. J., et
al., Nature (2006); 444:894-898; Goldberg, Y. P., et al., Clin.
Genet. (2007); 71:311-319). Conversely, gain of function mutations
in NaV1.7 have been established in two human heritable pain
conditions, primary erythromelalgia and familial rectal pain,
(Yang, Y., et al., J. Med. Genet. (2004), 41(3):171-4). In
addition, a single nucleotide polymorphism (R1150W) that has very
subtle effects on the time- and voltage-dependence of channel
gating has large effects on pain perception (Estacion, M., et al.,
2009. Ann Neurol 66: 862-6; Reimann, F., et al., Proc Natl Acad Sci
USA (2010), 107: 5148-53). About 10% of the patients with a variety
of pain conditions have the allele conferring greater sensitivity
to pain and thus might be more likely to respond to block of
NaV1.7. Because NaV1.7 is expressed in both sensory and sympathetic
neurons, one might expect that enhanced pain perception would be
accompanied by cardiovascular abnormalities such as hypertension,
but no correlation has been reported. Thus, both the CIP mutations
and SNP analysis suggest that human pain responses are more
sensitive to changes in NaV1.7 currents than are perturbations of
autonomic function.
[0006] Sodium channel blockers have been shown to be useful in the
treatment of pain, (see, e.g., Wood, J. N., et al., J. Neurobiol.
(2004), 61(1), 55-71. Genetic and functional studies have provided
evidence to support that activity of NaV1.7 as a major contributor
to pain signalling in mammals. (See Hajj, et al. Nature Reviews
Neuroscience; 2013, vol 14, 49-62; and Lee, et al. Cell; 2014, vol
157; 1-12). Presently, there are a limited number of effective
sodium channel blockers for the treatment of pain with a minimum of
adverse side effects which are currently in the clinic. Thus there
remains a need for selective voltage-gated sodium channel
modulators (e.g., modulators of NaV1.7) that can provide a greater
therapeutic index for treatment.
SUMMARY OF THE INVENTION
[0007] In one aspect the present invention provides novel compounds
having sodium channel blocking activity that are useful for the
treatment of pain. In a first embodiment (Embodiment 1; abbreviated
as "E1") the invention provides for a compound of Formula I:
##STR00002##
or a salt thereof; wherein each R.sup.AA is independently selected
from the group consisting of F, Cl, Br, I, --CN, --OR.sup.A1,
--(X.sup.RA)-(6-12 membered aryl), --(X.sup.RA)-(5-12 membered
heteroaryl), and --R.sup.A2, wherein said 6-12 membered aryl and
5-12 membered heteroaryl of R.sup.AA is optionally substituted with
from 1 to 5 substitutents independently selected from the group
consisting of F, Cl, Br, I, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl,
and C.sub.1-4(halo)alkoxy; R.sup.A1 is selected from the group
consisting of hydrogen, C.sub.1-8 alkyl, C.sub.2-8 alkenyl,
C.sub.1-8 haloalkyl, C.sub.3-8 cycloalkyl, phenyl and benzyl;
R.sup.A2 is selected from the group consisting of C.sub.1-8 alkyl
that is optionally substituted with one or more substituents
selected from oxo (.dbd.O), fluoro, amino, C.sub.1-4 alkylamino and
di(C.sub.1-4alkyl)amino; X.sup.RA is selected from the group
consisting of absent, --C(.dbd.O)--, and C.sub.1-4 alkylene;
wherein any C.sub.1-4 alkylene, of X.sup.RA is optionally
substituted with 1 to 3 substituents selected from the group
consisting of C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, and phenyl that
is optionally substituted with 1 to 5 substitutents selected from,
F, Cl, Br, I, --NH.sub.2, --OH, --CN, --NO.sub.2, C.sub.1-4 alkyl,
C.sub.1-4 haloalkyl, C.sub.1-4 alkoxy, C.sub.1-4(halo)alkoxy,
C.sub.1-4 alkylamino and C.sub.1-4 dialkylamino; n is 0, 1, 2, 3,
4, 5, 6, 7, or 8; ring "A" is a 3-15 membered carbocyclyl, a 6-12
membered aryl, a 5-12 membered heteroaryl, or a 3-15 membered
heterocyclyl; X.sup.1 and X.sup.2 are each independently selected
from the group consisting of absent, --S--, --O-- and
--N(R.sup.X)-- wherein R.sup.x is H, C.sub.1-8 alkyl, or C.sub.1-8
haloalkyl, and wherein if the subscript m is 0 then one of X.sup.1
or X.sup.2 is absent; L is C.sub.1-6 alkylene, wherein L is
optionally substituted with from 1 to 3 substituents independently
selected from the group consisting of C.sub.1-4 alkyl, C.sub.1-4
alkoxy, halo, oxo (.dbd.O), and C.sub.1-4 haloalkyl; wherein any
two substituents attached to the same atom on L are optionally
combined to form a 3- to 5-membered carbocyclic ring; m is 0 or 1;
R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are each independently
selected from the group consisting of H, F, Cl, Br, I, --CN,
C.sub.1-8 alkyl, C.sub.3-8 cycloalkyl, C.sub.1-8 haloalkyl and
C.sub.1-8 alkoxy; X is selected from the group consisting of O, S,
S.dbd.O, SO.sub.2, N(R.sup.N), C.dbd.O, CH.sub.2, and C.dbd.S,
wherein R.sup.N is selected from the group consisting of H,
C.sub.1-6 alkyl and acyl; ring "B" is selected from the group
consisting of cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and
cyclooctyl, wherein ring B is optionally substituted with one or
more groups independently selected from C.sub.1-4 alkyl; and
R.sup.6 is hydrogen or C.sub.1-6 alkyl
[0008] Further embodiments of the first embodiment of compounds of
the invention are described below.
[0009] E2. The compound of claim E1 wherein the compound of formula
(I) is a compound of formula (Ia):
##STR00003##
[0010] E3. The compound of claim E1 wherein the compound of formula
(I) is a compound of formula (Ib):
##STR00004##
[0011] E4. The compound of claim E1 wherein the compound of formula
(I) is a compound of formula (Ic):
##STR00005##
[0012] E5. The compound of claim E1 wherein the compound of formula
(I) is a compound of formula (Id):
##STR00006##
[0013] E6. The compound of claim E1 wherein the compound of formula
(I) is a compound of formula (Ie):
##STR00007##
[0014] E7. The compound of claim E1 wherein the compound of formula
(I) is a compound of formula (If):
##STR00008##
[0015] E8. The compound of claim E1 wherein the compound of formula
(I) is a compound of formula (Ig):
##STR00009##
[0016] E9. The compound of claim E1 wherein the compound of formula
(I) is a compound of formula (Ih):
##STR00010##
[0017] E10. The compound of claim E1 wherein the compound of
formula (I) is a compound of formula (Ij):
##STR00011##
[0018] E11. The compound of any one of E1-E10 wherein ring "B" is
selected from the group consisting of cyclobutyl, cyclopentyl, and
cyclohexyl.
[0019] E12. The compound of claim E1 wherein the compound of
formula (I) is a compound of formula (Ik):
##STR00012##
[0020] E13. The compound of claim E1 wherein the compound of
formula (I) is a compound of formula (Im):
##STR00013##
[0021] E14. The compound of claim E1 wherein the compound of
formula (I) is a compound of formula (In):
##STR00014##
[0022] E15. The compound of claim E1 wherein the compound of
formula (I) is a compound of formula (Io):
##STR00015##
[0023] E16. The compound of claim E1 wherein the compound of
formula (I) is a compound of formula (Ip):
##STR00016##
[0024] E17. The compound of claim E1 wherein the compound of
formula (I) is a compound of formula (Iq):
##STR00017##
[0025] E18. The compound of claim E1 wherein the compound of
formula (I) is a compound of formula (Ir):
##STR00018##
[0026] E19. The compound of claim E1 wherein the compound of
formula (I) is a compound of formula (Is):
##STR00019##
[0027] E20. The compound of any one of E1-E19 wherein n is 1, 2, 3,
4, 5, 6, 7, or 8.
[0028] E21. The compound of any one of E1-E19 wherein n is 2, 3, 4,
5, 6, 7, or 8.
[0029] E22. The compound of any one of E1-E19 wherein n is 2, 3, 4,
or 5.
[0030] E23. The compound of any one of E1-E22 wherein ring "A" is a
3-15 membered carbocyclyl.
[0031] E24. The compound of any one of E1-E22 wherein ring "A" is a
a 6-12 membered aryl.
[0032] E25. The compound of any one of E1-E22 wherein ring "A" is a
6-15 membered carbocycle.
[0033] E26. The compound of any one of E1-E22 wherein ring "A" is a
6-10 membered aryl.
[0034] E27. The compound of any one of E1-E22 wherein ring "A" is a
3-15 membered heterocycle.
[0035] E28. The compound of any one of E1-E22 wherein ring "A" is a
4-6 membered heterocycle.
[0036] E29. The compound of any one of E1-E22 wherein ring "A" is
selected from:
##STR00020##
[0037] E30. The compound of any one of E1-E22 wherein the group
##STR00021##
is selected from the group consisting of:
##STR00022##
[0038] E31. The compound of any one of E1-E29 wherein each R.sup.AA
is independently selected from the group consisting of methyl,
trifluoromethyl, ethyl, F, Cl, Br, and I.
[0039] E32. The compound of any one of E1-E31 wherein X.sup.1 is
absent; X.sup.2 is --O--; m is 1; and -(L)- is an optionally
substituted C.sub.1-4 alkylene.
[0040] E33. The compound of any one of E1-E31 wherein X.sup.1 is
absent; X.sup.2 is --O--; m is 1 and -(L)- is --CH.sub.2--,
--C(H)(CH.sub.3)--, or --CH.sub.2--CH.sub.2--.
[0041] E34. The compound of any one of E1-E31 wherein X.sup.1 is
absent; X.sup.2 is --O--; m is 1 and -(L)- is --CH.sub.2--.
[0042] E35. The compound of any one of E1, E3, E4, E11, E12, E13,
and E20-E34 wherein R.sup.3 is H or F.
[0043] E36. The compound of any one of E1, E3, E4, E11, E12, E13,
and E20-E35 wherein R.sup.5 is H or Cl.
[0044] E37. The compound of any one of E1-E36 wherein R.sup.2 is
selected from the group consisting of F, Cl, Br, I, and C.sub.3-8
cycloalkyl.
[0045] E38. The compound of any one of E1-E36 wherein R.sup.2 is
selected from the group consisting of Cl and cyclopropyl.
[0046] E39. The compound of any one of E1-E38 wherein R.sup.4 is
selected from the group consisting of F, Cl, Br, I, and C.sub.1-8
haloalkyl.
[0047] E40. The compound of any one of E1-E38 wherein R.sup.4 is
selected from the group consisting of F and trifluoromentyl.
[0048] E41. The compound of any one of E1-E40 wherein R.sup.6 is
C.sub.1-6 alkyl.
[0049] E42. The compound of any one of E1-E40 wherein R.sup.6 is
methyl.
[0050] E43. The compound of any one of E1-E40 wherein R.sup.6 is
hydrogen.
[0051] E44. The compound of any one of E1-E43 wherein X is selected
from the group consisting of C.dbd.O, S, S.dbd.O and SO.sub.2.
[0052] E45. The compound of any one of E1-E43 wherein X is
C.dbd.O.
[0053] E46. A compound selected from the group consisting of:
##STR00023## ##STR00024## ##STR00025## ##STR00026##
and salts thereof.
[0054] In another aspect the present invention provides for a
pharmaceutical composition comprising a compound of formula I or a
pharmaceutically acceptable salt thereof, and a pharmaceutically
acceptable excipient.
[0055] In another aspect the present invention provides for a
method of treating a disease or condition in a mammal selected from
the group consisting of pain, depression, cardiovascular diseases,
respiratory diseases, and psychiatric diseases, and combinations
thereof, wherein the method comprises administering to the mammal
in need thereof a therapeutically effective amount of a compound of
formula I, or a pharmaceutically acceptable salt thereof. In
another aspect of the present invention said disease or condition
is selected from the group consisting of neuropathic pain,
inflammatory pain, visceral pain, cancer pain, chemotherapy pain,
trauma pain, surgical pain, post-surgical pain, childbirth pain,
labor pain, neurogenic bladder, ulcerative colitis, chronic pain,
persistent pain, peripherally mediated pain, centrally mediated
pain, chronic headache, migraine headache, sinus headache, tension
headache, phantom limb pain, dental pain, peripheral nerve injury
or a combination thereof. In another aspect of the present
invention said disease or condition is selected from the group
consisting of pain associated with HIV, HIV treatment induced
neuropathy, trigeminal neuralgia, post-herpetic neuralgia, eudynia,
heat sensitivity, tosarcoidosis, irritable bowel syndrome, Crohns
disease, pain associated with multiple sclerosis (MS), amyotrophic
lateral sclerosis (ALS), diabetic neuropathy, peripheral
neuropathy, arthritis, rheumatoid arthritis, osteoarthritis,
atherosclerosis, paroxysmal dystonia, myasthenia syndromes,
myotonia, malignant hyperthermia, cystic fibrosis,
pseudoaldosteronism, rhabdomyolysis, hypothyroidism, bipolar
depression, anxiety, schizophrenia, sodium channel toxi related
illnesses, familial erythromelalgia, primary erythromelalgia,
familial rectal pain, cancer, epilepsy, partial and general tonic
seizures, restless leg syndrome, arrhythmias, fibromyalgia,
neuroprotection under ischaemic conditions cause by stroke or
neural trauma, tach-arrhythmias, atrial fibrillation and
ventricular fibrillation.
[0056] In another aspect the present invention provides for a
method of treating pain in a mammal by the inhibition of ion flux
through a voltage-dependent sodium channel in the mammal, wherein
the method comprises administering to the mammal in need thereof a
therapeutically effective amount of a compound of formula I, or a
pharmaceutically acceptable salt thereof.
[0057] In another aspect the present invention provides for a
method of decreasing ion flux through a voltage-dependent sodium
channel in a cell in a mammal, wherein the method comprises
contacting the cell with a compound of formula I, or a
pharmaceutically acceptable salt thereof.
[0058] In another aspect the present invention provides for a
method of treating pruritus in a mammal, wherein the method
comprises administering to the mammal in need thereof a
therapeutically effective amount of a compound of formula I, or a
pharmaceutically acceptable salt thereof.
[0059] In another aspect the present invention provides for a
method of treating cancer in a mammal, wherein the method comprises
administering to the mammal in need thereof a therapeutically
effective amount a compound of formula I, or a pharmaceutically
acceptable salt thereof.
[0060] In another aspect the present invention provides for a
method of treating, but not preventing, pain in a mammal, wherein
the method comprises administering to the mammal in need thereof a
therapeutically effective amount of a compound of formula I, or a
pharmaceutically acceptable salt thereof. In another aspect of the
present invention the pain is selected from the group consisting of
neuropathic pain, inflammatory pain, visceral pain, cancer pain,
chemotherapy pain, trauma pain, surgical pain, post-surgical pain,
childbirth pain, labor pain, neurogenic bladder, ulcerative
colitis, chronic pain, persistent pain, peripherally mediated pain,
centrally mediated pain, chronic headache, migraine headache, sinus
headache, tension headache, phantom limb pain, dental pain,
peripheral nerve injury or a combination thereof. In another aspect
the present invention the pain is associated with a disease or
condition selected from the group consisting of HIV, HIV treatment
induced neuropathy, trigeminal neuralgia, post-herpetic neuralgia,
eudynia, heat sensitivity, tosarcoidosis, irritable bowel syndrome,
Crohns disease, pain associated with multiple sclerosis (MS),
amyotrophic lateral sclerosis (ALS), diabetic neuropathy,
peripheral neuropathy, arthritis, rheumatoid arthritis,
osteoarthritis, atherosclerosis, paroxysmal dystonia, myasthenia
syndromes, myotonia, malignant hyperthermia, cystic fibrosis,
pseudoaldosteronism, rhabdomyolysis, hypothyroidism, bipolar
depression, anxiety, schizophrenia, sodium channel toxi related
illnesses, familial erythromelalgia, primary erythromelalgia,
familial rectal pain, cancer, epilepsy, partial and general tonic
seizures, restless leg syndrome, arrhythmias, fibromyalgia,
neuroprotection under ischaemic conditions cause by stroke or
neural trauma, tach-arrhythmias, atrial fibrillation and
ventricular fibrillation.
[0061] In another aspect the present invention provides for a
method for the treatment or prophylaxis of pain, depression,
cardiovascular disease, respiratory disease, or psychiatric
disease, or a combinations thereof, in an animal which method
comprises administering an effective amount of a compound of
formula I, or a pharmaceutically acceptable salt thereof.
[0062] In another aspect the present invention provides for a
compound of formula I, or a pharmaceutically acceptable salt
thereof for the use as a medicament for the treatment of diseases
and disorders selected from the group consisting of pain,
depression, cardiovascular diseases, respiratory diseases, and
psychiatric diseases, or a combination thereof.
[0063] In another aspect the present invention provides for the use
of a compound of formula I, or a pharmaceutically acceptable salt
thereof for the manufacture of a medicament for the treatment of
diseases and disorders selected from the group consisting of pain,
depression, cardiovascular diseases, respiratory diseases, and
psychiatric diseases, or a combination thereof.
[0064] In another aspect the present invention provides for the
invention as described herein.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0065] As used herein, the term "alkyl", by itself or as part of
another substituent, means, unless otherwise stated, a straight or
branched chain hydrocarbon radical, having the number of carbon
atoms designated (i.e., C.sub.1-8 means one to eight carbons).
Examples of alkyl groups include methyl, ethyl, n-propyl,
iso-propyl, n-butyl, t-butyl, iso-butyl, sec-butyl, n-pentyl,
n-hexyl, n-heptyl, n-octyl, and the like. The term "alkenyl" refers
to an unsaturated alkyl radical having one or more double bonds.
Similarly, the term "alkynyl" refers to an unsaturated alkyl
radical having one or more triple bonds. Examples of such
unsaturated alkyl groups include vinyl, 2-propenyl, crotyl,
2-isopentenyl, 2-(butadienyl), 2,4-pentadienyl,
3-(1,4-pentadienyl), ethynyl, 1- and 3-propynyl, 3-butynyl, and the
higher homologs and isomers.
[0066] The term "heteroalkyl," by itself or in combination with
another term, means, unless otherwise stated, a stable straight or
branched chain hydrocarbon radical, consisting of the stated number
of carbon atoms and from one to three heteroatoms selected from the
group consisting of O, N, Si and S, and wherein the nitrogen and
sulfur atoms can optionally be oxidized and the nitrogen heteroatom
can optionally be quaternized. The heteroatom(s) O, N and S can be
placed at any interior position of the heteroalkyl group. The
heteroatom Si can be placed at any position of the heteroalkyl
group, including the position at which the alkyl group is attached
to the remainder of the molecule. A "heteroalkyl" can contain up to
three units of unsaturation, and also include mono- and
poly-halogenated variants, or combinations thereof. Examples
include --CH.sub.2--CH.sub.2--O--CH.sub.3,
--CH.sub.2--CH.sub.2--O--CF.sub.3,
--CH.sub.2--CH.sub.2--NH--CH.sub.3,
--CH.sub.2--CH.sub.2--N(CH.sub.3)--CH.sub.3,
--CH.sub.2--S--CH.sub.2--CH.sub.3, --S(O)--CH.sub.3,
--CH.sub.2--CH.sub.2--S(O).sub.2--CH.sub.3,
--CH.dbd.CH--O--CH.sub.3, --Si(CH.sub.3).sub.3,
--CH.sub.2--CH.dbd.N--OCH.sub.3, and
--CH.dbd.CH.dbd.N(CH.sub.3)--CH.sub.3. Up to two heteroatoms can be
consecutive, such as, for example, --CH.sub.2--NH--OCH.sub.3 and
--CH.sub.2--O--Si(CH.sub.3).sub.3.
[0067] The term "alkylene" by itself or as part of another
substituent means a divalent radical derived from an alkane
(including branched alkane), as exemplified by
--CH.sub.2CH.sub.2CH.sub.2CH.sub.2-- and
--CH(CH.sub.2)CH.sub.2CH.sub.2--. Typically, an alkyl (or alkylene)
group will have from 1 to 24 carbon atoms, with those groups having
10 or fewer carbon atoms being preferred in the present invention.
"Alkenylene" and "alkynylene" refer to the unsaturated forms of
"alkylene" having double or triple bonds, respectively.
[0068] The term "heteroalkylene" by itself or as part of another
substituent means a divalent radical, saturated or unsaturated or
polyunsaturated, derived from heteroalkyl, as exemplified by
--CH.sub.2--CH.sub.2--S--CH.sub.2CH.sub.2-- and
--CH.sub.2--S--CH.sub.2--CH.sub.2--NH--CH.sub.2--,
--O--CH.sub.2--CH.dbd.CH--,
--CH.sub.2--CH.dbd.C(H)CH.sub.2--O--CH.sub.2-- and
--S--CH.sub.2--C.ident.C--. For heteroalkylene groups, heteroatoms
can also occupy either or both of the chain termini (e.g.,
alkyleneoxy, alkylenedioxy, alkyleneamino, alkylenediamino, and the
like).
[0069] The terms "alkoxy," "alkylamino" and "alkylthio", are used
in their conventional sense, and refer to those alkyl groups
attached to the remainder of the molecule via an oxygen atom
("oxy"), an amino group ("amino") or thio group. Additionally, for
dialkylamino groups, the alkyl portions can be the same or
different.
[0070] The term "acyl" means a group (C.sub.1-6
alkyl)-C(.dbd.O)--.
[0071] The terms "halo" or "halogen," by themselves or as part of
another substituent, mean, unless otherwise stated, a fluorine,
chlorine, bromine, or iodine atom. The term "(halo)alkyl" is meant
to include both a "alkyl" and "haloalkyl" substituent.
Additionally, the term "haloalkyl," is meant to include
monohaloalkyl and polyhaloalkyl. For example, the term "C.sub.1-4
haloalkyl" is mean to include trifluoromethyl,
2,2,2-trifluoroethyl, 4-chlorobutyl, 3-bromopropyl, difluoromethyl,
and the like.
[0072] The term "aryl" as used herein refers to a single all carbon
aromatic ring or a multiple condensed all carbon ring system
wherein at least one of the rings is aromatic. For example, in
certain embodiments, an aryl group has 6 to 20 carbon atoms, 6 to
14 carbon atoms, 6 to 12 carbon atoms, or 6 to 10 carbon atoms.
Aryl includes a phenyl radical. Aryl also includes multiple
condensed ring systems (e.g., ring systems comprising 2, 3 or 4
rings) having about 9 to 20 carbon atoms in which at least one ring
is aromatic and wherein the other rings may be aromatic or not
aromatic (i.e., carbocycle). Such multiple condensed ring systems
are optionally substituted with one or more (e.g., 1, 2 or 3) oxo
groups on any carbocycle portion of the multiple condensed ring
system. The rings of the multiple condensed ring system can be
connected to each other via fused, spiro and bridged bonds when
allowed by valency requirements. It is to be understood that the
point of attachment of a multiple condensed ring system, as defined
above, can be at any position of the ring system including an
aromatic or a carbocycle portion of the ring. Non-limiting examples
of aryl groups include, but are not limited to, phenyl, indenyl,
naphthyl, 1, 2, 3, 4-tetrahydronaphthyl, anthracenyl, and the
like.
[0073] The term "carbocycle" or "carbocyclyl" refers to a single
saturated (i.e., cycloalkyl) or a single partially unsaturated
(e.g., cycloalkenyl, cycloalkadienyl, etc.) all carbon ring having
3 to 7 carbon atoms (i.e., (C.sub.3-C.sub.7)carbocycle). The term
"carbocycle" or "carbocyclyl" also includes multiple condensed,
saturated and partially unsaturated all carbon ring systems (e.g.,
ring systems comprising 2, 3 or 4 carbocyclic rings). Accordingly,
carbocycle includes multicyclic carbocyles such as a bicyclic
carbocycles (e.g., bicyclic carbocycles having about 3 to 15 carbon
atoms, about 6 to 15 carbon atoms, or 6 to 12 carbon atoms such as
bicyclo[3.1.0]hexane and bicyclo[2.1.1]hexane), and polycyclic
carbocycles (e.g tricyclic and tetracyclic carbocycles with up to
about 20 carbon atoms). The rings of the multiple condensed ring
system can be connected to each other via fused, spiro and bridged
bonds when allowed by valency requirements. For example,
multicyclic carbocyles can be connected to each other via a single
carbon atom to form a spiro connection (e.g., spiropentane,
spiro[4,5]decane, etc), via two adjacent carbon atoms to form a
fused connection (e.g., carbocycles such as decahydronaphthalene,
norsabinane, norcarane) or via two non-adjacent carbon atoms to
form a bridged connection (e.g., norbornane, bicyclo[2.2.2]octane,
etc). The "carbocycle" or "carbocyclyl" can also be optionally
substituted with one or more (e.g., 1, 2 or 3) oxo groups. In one
embodiment the term carbocycle includes a C.sub.3-15 carbocycle. In
one embodiment the term carbocycle includes a C.sub.6-15
carbocycle. In one embodiment the term carbocycle includes a
C.sub.3-8 carbocycle. In one embodiment the term carbocycle
includes a C.sub.3-6 carbocycle. In one embodiment the term
carbocycle includes a C.sub.3-5 carbocycle. Non-limiting examples
of carbocycles include cyclopropyl, cyclobutyl, cyclopentyl,
1-cyclopent-1-enyl, 1-cyclopent-2-enyl, 1-cyclopent-3-enyl,
cyclohexyl, 1-cyclohex-1-enyl, 1-cyclohex-2-enyl,
bicyclo[2.2.1]heptane, pinane, adamantane, norborene, spirocyclic
C.sub.5-12 alkane, and 1-cyclohex-3-enyl.
[0074] The term "heteroaryl" as used herein refers to a single
aromatic ring that has at least one atom other than carbon in the
ring, wherein the atom is selected from the group consisting of
oxygen, nitrogen and sulfur; "heteroaryl" also includes multiple
condensed ring systems that have at least one such aromatic ring,
which multiple condensed ring systems are further described below.
Thus, "heteroaryl" includes single aromatic rings of from about 1
to 6 carbon atoms and about 1-4 heteroatoms selected from the group
consisting of oxygen, nitrogen and sulfur. The sulfur and nitrogen
atoms may also be present in an oxidized form provided the ring is
aromatic. Exemplary heteroaryl ring systems include but are not
limited to pyridyl, pyrimidinyl, oxazolyl or furyl. "Heteroaryl"
also includes multiple condensed ring systems (e.g., ring systems
comprising 2, 3 or 4 rings) wherein a heteroaryl group, as defined
above, is condensed with one or more rings selected from
heteroaryls (to form for example a naphthyridinyl such as
1,8-naphthyridinyl), heterocycles, (to form for example a 1, 2, 3,
4-tetrahydronaphthyridinyl such as
1,2,3,4-tetrahydro-1,8-naphthyridinyl), carbocycles (to form for
example 5,6,7,8-tetrahydroquinolyl) and aryls (to form for example
indazolyl) to form the multiple condensed ring system. Thus, a
heteroaryl (a single aromatic ring or multiple condensed ring
system) has about 1-20 carbon atoms and about 1-6 heteroatoms
within the heteroaryl ring. Such multiple condensed ring systems
may be optionally substituted with one or more (e.g., 1, 2, 3 or 4)
oxo groups on the carbocycle or heterocycle portions of the
condensed ring. The rings of the multiple condensed ring system can
be connected to each other via fused, spiro and bridged bonds when
allowed by valency requirements. It is to be understood that the
individual rings of the multiple condensed ring system may be
connected in any order relative to one another. It is also to be
understood that the point of attachment of a multiple condensed
ring system (as defined above for a heteroaryl) can be at any
position of the multiple condensed ring system including a
heteroaryl, heterocycle, aryl or carbocycle portion of the multiple
condensed ring system. It is also to be understood that the point
of attachment for a heteroaryl or heteroaryl multiple condensed
ring system can be at any suitable atom of the heteroaryl or
heteroaryl multiple condensed ring system including a carbon atom
and a heteroatom (e.g., a nitrogen). Exemplary heteroaryls include
but are not limited to pyridyl, pyrrolyl, pyrazinyl, pyrimidinyl,
pyridazinyl, pyrazolyl, thienyl, indolyl, imidazolyl, oxazolyl,
isoxazolyl, thiazolyl, furyl, oxadiazolyl, thiadiazolyl, quinolyl,
isoquinolyl, benzothiazolyl, benzoxazolyl, indazolyl, quinoxalyl,
quinazolyl, 5,6,7,8-tetrahydroisoquinolinyl benzofuranyl,
benzimidazolyl, thianaphthenyl, pyrrolo[2,3-b]pyridinyl,
quinazolinyl-4(3H)-one, triazolyl, 4,5,6,7-tetrahydro-1H-indazole
and
3b,4,4a,5-tetrahydro-1H-cyclopropa[3,4]cyclo-penta[1,2-c]pyrazole.
[0075] The term "heterocyclyl" or "heterocycle" as used herein
refers to a single saturated or partially unsaturated ring that has
at least one atom other than carbon in the ring, wherein the atom
is selected from the group consisting of oxygen, nitrogen and
sulfur; the term also includes multiple condensed ring systems that
have at least one such saturated or partially unsaturated ring,
which multiple condensed ring systems are further described below.
Thus, the term includes single saturated or partially unsaturated
rings (e.g., 3, 4, 5, 6 or 7-membered rings) from about 1 to 6
carbon atoms and from about 1 to 3 heteroatoms selected from the
group consisting of oxygen, nitrogen and sulfur in the ring. The
ring may be substituted with one or more (e.g., 1, 2 or 3) oxo
groups and the sulfur and nitrogen atoms may also be present in
their oxidized forms. Exemplary heterocycles include but are not
limited to azetidinyl, tetrahydrofuranyl and piperidinyl. The term
"heterocycle" also includes multiple condensed ring systems (e.g.,
ring systems comprising 2, 3 or 4 rings) wherein a single
heterocycle ring (as defined above) can be condensed with one or
more groups selected from heterocycles (to form for example a
1,8-decahydronapthyridinyl), carbocycles (to form for example a
decahydroquinolyl) and aryls to form the multiple condensed ring
system. Thus, a heterocycle (a single saturated or single partially
unsaturated ring or multiple condensed ring system) has about 2-20
carbon atoms and 1-6 heteroatoms within the heterocycle ring. Such
multiple condensed ring systems may be optionally substituted with
one or more (e.g., 1, 2, 3 or 4) oxo groups on the carbocycle or
heterocycle portions of the multiple condensed ring. The rings of
the multiple condensed ring system can be connected to each other
via fused, spiro and bridged bonds when allowed by valency
requirements. It is to be understood that the individual rings of
the multiple condensed ring system may be connected in any order
relative to one another. It is also to be understood that the point
of attachment of a multiple condensed ring system (as defined above
for a heterocycle) can be at any position of the multiple condensed
ring system including a heterocycle, aryl and carbocycle portion of
the ring. It is also to be understood that the point of attachment
for a heterocycle or heterocycle multiple condensed ring system can
be at any suitable atom of the heterocycle or heterocycle multiple
condensed ring system including a carbon atom and a heteroatom
(e.g., a nitrogen). In one embodiment the term heterocycle includes
a C.sub.2-20 heterocycle. In one embodiment the term heterocycle
includes a C.sub.2-7 heterocycle. In one embodiment the term
heterocycle includes a C.sub.2-5 heterocycle. In one embodiment the
term heterocycle includes a C.sub.2-4 heterocycle. In one
embodiment the term heterocycle includes a 3-15 membered
heterocycle. In one embodiment the term heterocycle includes a 3-8
membered heterocycle. In one embodiment the term heterocycle
includes a 3-6 membered heterocycle. In one embodiment the term
heterocycle includes a 4-6 membered heterocycle. Exemplary
heterocycles include, but are not limited to aziridinyl,
azetidinyl, pyrrolidinyl, piperidinyl, homopiperidinyl,
morpholinyl, thiomorpholinyl, piperazinyl, tetrahydrofuranyl,
dihydrooxazolyl, tetrahydropyranyl, tetrahydrothiopyranyl,
1,2,3,4-tetrahydroquinolyl, benzoxazinyl, dihydrooxazolyl,
chromanyl, 1,2-dihydropyridinyl, 2,3-dihydrobenzofuranyl,
1,3-benzodioxolyl, 1,4-benzodioxanyl,
spiro[cyclopropane-1,1'-isoindolinyl]-3'-one, isoindolinyl-1-one,
2-oxa-6-azaspiro[3.3]heptanyl, imidazolidin-2-one
N-methylpiperidine, imidazolidine, pyrazolidine, butyrolactam,
valerolactam, imidazolidinone, hydantoin, dioxolane, phthalimide,
1,4-dioxane, thiomorpholine, thiomorpholine-S-oxide,
thiomorpholine-S,S-oxide, pyran, 3-pyrroline, thiopyran, pyrone,
tetrhydrothiophene, quinuclidine, tropane, 2-azaspiro[3.3]heptane,
(1R,5S)-3-azabicyclo[3.2.1]octane,
(1s,4s)-2-azabicyclo[2.2.2]octane,
(1R,4R)-2-oxa-5-azabicyclo[2.2.2]octane and pyrrolidin-2-one.
[0076] The term "heterocyclyloxy" as used herein refers to a group
(heterocyclyl)-O--, wherein the term heterocyclyl has the meaning
defined herein.
[0077] The term "alkoxycarbonyl" as used herein refers to a group
(alkyl)-O--C(.dbd.O)--, wherein the term alkyl has the meaning
defined herein.
[0078] As used herein, the term "heteroatom" is meant to include
oxygen (O), nitrogen (N), sulfur (S) and silicon (Si).
[0079] As used herein, the term "chiral" refers to molecules which
have the property of non-superimposability of the mirror image
partner, while the term "achiral" refers to molecules which are
superimposable on their mirror image partner.
[0080] As used herein, the term "stereoisomers" refers to compounds
which have identical chemical constitution, but differ with regard
to the arrangement of the atoms or groups in space.
[0081] As used herein a wavy line "" that intersects a bond in a
chemical structure indicates the point of attachment of the bond
that the wavy bond intersects in the chemical structure to the
remainder of a molecule.
[0082] As used herein, the term "C-linked" means that the group
that the term describes is attached the remainder of the molecule
through a ring carbon atom.
[0083] As used herein, the term "N-linked" means that the group
that the term describes is attached to the remainder of the
molecule through a ring nitrogen atom.
[0084] "Diastereomer" refers to a stereoisomer with two or more
centers of chirality and whose molecules are not mirror images of
one another. Diastereomers have different physical properties, e.g.
melting points, boiling points, spectral properties, and
reactivities. Mixtures of diastereomers can separate under high
resolution analytical procedures such as electrophoresis and
chromatography.
[0085] "Enantiomers" refer to two stereoisomers of a compound which
are non-superimposable mirror images of one another.
[0086] Stereochemical definitions and conventions used herein
generally follow S. P. Parker, Ed., McGraw-Hill Dictionary of
Chemical Terms (1984) McGraw-Hill Book Company, New York; and
Eliel, E. and Wilen, S., "Stereochemistry of Organic Compounds",
John Wiley & Sons, Inc., New York, 1994. The compounds of the
invention can contain asymmetric or chiral centers, and therefore
exist in different stereoisomeric forms. It is intended that all
stereoisomeric forms of the compounds of the invention, including
but not limited to, diastereomers, enantiomers and atropisomers, as
well as mixtures thereof such as racemic mixtures, form part of the
present invention. Many organic compounds exist in optically active
forms, i.e., they have the ability to rotate the plane of
plane-polarized light. In describing an optically active compound,
the prefixes D and L, or R and S, are used to denote the absolute
configuration of the molecule about its chiral center(s). The
prefixes d and 1 or (+) and (-) are employed to designate the sign
of rotation of plane-polarized light by the compound, with (-) or 1
meaning that the compound is levorotatory. A compound prefixed with
(+) or d is dextrorotatory. For a given chemical structure, these
stereoisomers are identical except that they are mirror images of
one another. A specific stereoisomer can also be referred to as an
enantiomer, and a mixture of such isomers is often called an
enantiomeric mixture. A 50:50 mixture of enantiomers is referred to
as a racemic mixture or a racemate, which can occur where there has
been no stereoselection or stereospecificity in a chemical reaction
or process. The terms "racemic mixture" and "racemate" refer to an
equimolar mixture of two enantiomeric species, devoid of optical
activity.
[0087] When a bond in a compound formula herein is drawn in a
non-stereochemical manner (e.g. flat), the atom to which the bond
is attached includes all stereochemical possibilities. When a bond
in a compound formula herein is drawn in a defined stereochemical
manner (e.g. bold, bold-wedge, dashed or dashed-wedge), it is to be
understood that the atom to which the stereochemical bond is
attached is enriched in the absolute stereoisomer depicted unless
otherwise noted. In one embodiment, the compound may be at least
51% the absolute stereoisomer depicted. In another embodiment, the
compound may be at least 80% the absolute stereoisomer depicted. In
another embodiment, the compound may be at least 90% the absolute
stereoisomer depicted. In another embodiment, the compound may be
at least 95% the absolute stereoisomer depicted. In another
embodiment, the compound may be at least 97% the absolute
stereoisomer depicted. In another embodiment, the compound may be
at least 98% the absolute stereoisomer depicted. In another
embodiment, the compound may be at least 99% the absolute
stereoisomer depicted.
[0088] As used herein, the term "tautomer" or "tautomeric form"
refers to structural isomers of different energies which are
interconvertible via a low energy barrier. For example, proton
tautomers (also known as prototropic tautomers) include
interconversions via migration of a proton, such as keto-enol and
imine-enamine isomerizations. Valence tautomers include
interconversions by reorganization of some of the bonding
electrons.
[0089] As used herein, the term "solvate" refers to an association
or complex of one or more solvent molecules and a compound of the
invention. Examples of solvents that form solvates include, but are
not limited to, water, isopropanol, ethanol, methanol, DMSO, ethyl
acetate, acetic acid, and ethanolamine. The term "hydrate" refers
to the complex where the solvent molecule is water.
[0090] As used herein, the term "protecting group" refers to a
substituent that is commonly employed to block or protect a
particular functional group on a compound. For example, an
"amino-protecting group" is a substituent attached to an amino
group that blocks or protects the amino functionality in the
compound. Suitable amino-protecting groups include acetyl,
trifluoroacetyl, t-butoxycarbonyl (BOC), benzyloxycarbonyl (CBZ)
and 9-fluorenylmethylenoxycarbonyl (Fmoc). Similarly, a
"hydroxy-protecting group" refers to a substituent of a hydroxy
group that blocks or protects the hydroxy functionality. Suitable
protecting groups include acetyl and silyl. A "carboxy-protecting
group" refers to a substituent of the carboxy group that blocks or
protects the carboxy functionality. Common carboxy-protecting
groups include phenylsulfonylethyl, cyanoethyl,
2-(trimethylsilyl)ethyl, 2-(trimethylsilyl)ethoxymethyl,
2-(p-toluenesulfonyl)ethyl, 2-(p-nitrophenylsulfenyl)ethyl,
2-(diphenylphosphino)-ethyl, nitroethyl and the like. For a general
description of protecting groups and their use, see P. G. M. Wuts
and T. W. Greene, Greene's Protective Groups in Organic Synthesis
4.sup.th edition, Wiley-Interscience, New York, 2006.
[0091] As used herein, the term "mammal" includes, but is not
limited to, humans, mice, rats, guinea pigs, monkeys, dogs, cats,
horses, cows, pigs, and sheep.
[0092] As used herein, the term "pharmaceutically acceptable salts"
is meant to include salts of the active compounds which are
prepared with relatively nontoxic acids or bases, depending on the
particular substituents found on the compounds described herein.
When compounds of the present invention contain relatively acidic
functionalities, base addition salts can be obtained by contacting
the neutral form of such compounds with a sufficient amount of the
desired base, either neat or in a suitable inert solvent. Examples
of salts derived from pharmaceutically-acceptable inorganic bases
include aluminum, ammonium, calcium, copper, ferric, ferrous,
lithium, magnesium, manganic, manganous, potassium, sodium, zinc
and the like. Salts derived from pharmaceutically-acceptable
organic bases include salts of primary, secondary and tertiary
amines, including substituted amines, cyclic amines,
naturally-occurring amines and the like, such as arginine, betaine,
caffeine, choline, N,N'-dibenzylethylenediamine, diethylamine,
2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine,
ethylenediamine, N-ethylmorpholine, N-ethylpiperidine, glucamine,
glucosamine, histidine, hydrabamine, isopropylamine, lysine,
methylglucamine, morpholine, piperazine, piperidine, polyamine
resins, procaine, purines, theobromine, triethylamine,
trimethylamine, tripropylamine, tromethamine and the like. When
compounds of the present invention contain relatively basic
functionalities, acid addition salts can be obtained by contacting
the neutral form of such compounds with a sufficient amount of the
desired acid, either neat or in a suitable inert solvent. Examples
of pharmaceutically acceptable acid addition salts include those
derived from inorganic acids like hydrochloric, hydrobromic,
nitric, carbonic, monohydrogencarbonic, phosphoric,
monohydrogenphosphoric, dihydrogenphosphoric, sulfuric,
monohydrogensulfuric, hydriodic, or phosphorous acids and the like,
as well as the salts derived from relatively nontoxic organic acids
like acetic, propionic, isobutyric, malonic, benzoic, succinic,
suberic, fumaric, mandelic, phthalic, benzenesulfonic,
p-tolylsulfonic, citric, tartaric, methanesulfonic, and the like.
Also included are salts of amino acids such as arginate and the
like, and salts of organic acids like glucuronic or galactunoric
acids and the like (see, for example, Berge, S. M., et al.,
"Pharmaceutical Salts", Journal of Pharmaceutical Science, 1977,
66, 1-19). Certain specific compounds of the present invention
contain both basic and acidic functionalities that allow the
compounds to be converted into either base or acid addition
salts.
[0093] The neutral forms of the compounds can be regenerated by
contacting the salt with a base or acid and isolating the parent
compound in the conventional manner. The parent form of the
compound differs from the various salt forms in certain physical
properties, such as solubility in polar solvents, but otherwise the
salts are equivalent to the parent form of the compound for the
purposes of the present invention.
[0094] In addition to salt forms, the present invention provides
compounds which are in a prodrug form. As used herein the term
"prodrug" refers to those compounds that readily undergo chemical
changes under physiological conditions to provide the compounds of
the present invention. Additionally, prodrugs can be converted to
the compounds of the present invention by chemical or biochemical
methods in an ex vivo environment. For example, prodrugs can be
slowly converted to the compounds of the present invention when
placed in a transdermal patch reservoir with a suitable enzyme or
chemical reagent.
[0095] Prodrugs of the invention include compounds wherein an amino
acid residue, or a polypeptide chain of two or more (e.g., two,
three or four) amino acid residues, is covalently joined through an
amide or ester bond to a free amino, hydroxy or carboxylic acid
group of a compound of the present invention. The amino acid
residues include but are not limited to the 20 naturally occurring
amino acids commonly designated by three letter symbols and also
includes phosphoserine, phosphothreonine, phosphotyrosine,
4-hydroxyproline, hydroxylysine, demosine, isodemosine,
gamma-carboxyglutamate, hippuric acid, octahydroindole-2-carboxylic
acid, statine, 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid,
penicillamine, ornithine, 3-methylhistidine, norvaline,
beta-alanine, gamma-aminobutyric acid, citrulline, homocysteine,
homoserine, methyl-alanine, para-benzoylphenylalanine,
phenylglycine, propargylglycine, sarcosine, methionine sulfone and
tert-butylglycine.
[0096] Additional types of prodrugs are also encompassed. For
instance, a free carboxyl group of a compound of the invention can
be derivatized as an amide or alkyl ester. As another example,
compounds of this invention comprising free hydroxy groups can be
derivatized as prodrugs by converting the hydroxy group into a
group such as, but not limited to, a phosphate ester,
hemisuccinate, dimethylaminoacetate, or
phosphoryloxymethyloxycarbonyl group, as outlined in Fleisher, D.
et al., (1996) Improved oral drug delivery: solubility limitations
overcome by the use of prodrugs Advanced Drug Delivery Reviews,
19:115. Carbamate prodrugs of hydroxy and amino groups are also
included, as are carbonate prodrugs, sulfonate esters and sulfate
esters of hydroxy groups. Derivatization of hydroxy groups as
(acyloxy)methyl and (acyloxy)ethyl ethers, wherein the acyl group
can be an alkyl ester optionally substituted with groups including,
but not limited to, ether, amine and carboxylic acid
functionalities, or where the acyl group is an amino acid ester as
described above, are also encompassed. Prodrugs of this type are
described in J. Med. Chem., (1996), 39:10. More specific examples
include replacement of the hydrogen atom of the alcohol group with
a group such as (C.sub.1-6)alkanoyloxymethyl,
1-((C.sub.1-6)alkanoyloxy)ethyl,
1-methyl-1-((C.sub.1-6)alkanoyloxy)ethyl,
(C.sub.1-6)alkoxycarbonyloxymethyl,
N--(C.sub.1-6)alkoxycarbonylaminomethyl, succinoyl,
(C.sub.1-6)alkanoyl, alpha-amino(C.sub.1-4)alkanoyl, arylacyl and
alpha-aminoacyl, or alpha-aminoacyl-alpha-aminoacyl, where each
alpha-aminoacyl group is independently selected from the naturally
occurring L-amino acids, P(O)(OH).sub.2,
--P(O)(O(C.sub.1-6)alkyl).sub.2 or glycosyl (the radical resulting
from the removal of a hydroxyl group of the hemiacetal form of a
carbohydrate).
[0097] For additional examples of prodrug derivatives, see, for
example, a) Design of Prodrugs, edited by H. Bundgaard, (Elsevier,
1985) and Methods in Enzymology, Vol. 42, p. 309-396, edited by K.
Widder, et al. (Academic Press, 1985); b) A Textbook of Drug Design
and Development, edited by Krogsgaard-Larsen and H. Bundgaard,
Chapter 5 "Design and Application of Prodrugs," by H. Bundgaard p.
113-191 (1991); c) H. Bundgaard, Advanced Drug Delivery Reviews,
8:1-38 (1992); d) H. Bundgaard, et al., Journal of Pharmaceutical
Sciences, 77:285 (1988); and e) N. Kakeya, et al., Chem. Pharm.
Bull., 32:692 (1984), each of which is specifically incorporated
herein by reference.
[0098] Additionally, the present invention provides for metabolites
of compounds of the invention. As used herein, a "metabolite"
refers to a product produced through metabolism in the body of a
specified compound or salt thereof. Such products can result for
example from the oxidation, reduction, hydrolysis, amidation,
deamidation, esterification, deesterification, enzymatic cleavage,
and the like, of the administered compound.
[0099] Metabolite products typically are identified by preparing a
radiolabelled (e.g., .sup.14C or .sup.3H) isotope of a compound of
the invention, administering it parenterally in a detectable dose
(e.g., greater than about 0.5 mg/kg) to an animal such as rat,
mouse, guinea pig, monkey, or to man, allowing sufficient time for
metabolism to occur (typically about 30 seconds to 30 hours) and
isolating its conversion products from the urine, blood or other
biological samples. These products are easily isolated since they
are labeled (others are isolated by the use of antibodies capable
of binding epitopes surviving in the metabolite). The metabolite
structures are determined in conventional fashion, e.g., by MS,
LC/MS or NMR analysis. In general, analysis of metabolites is done
in the same way as conventional drug metabolism studies well known
to those skilled in the art. The metabolite products, so long as
they are not otherwise found in vivo, are useful in diagnostic
assays for therapeutic dosing of the compounds of the
invention.
[0100] Certain compounds of the present invention can exist in
unsolvated forms as well as solvated forms, including hydrated
forms. In general, the solvated forms are equivalent to unsolvated
forms and are intended to be encompassed within the scope of the
present invention. Certain compounds of the present invention can
exist in multiple crystalline or amorphous forms. In general, all
physical forms are equivalent for the uses contemplated by the
present invention and are intended to be within the scope of the
present invention.
[0101] Certain compounds of the present invention possess
asymmetric carbon atoms (optical centers) or double bonds; the
racemates, diastereomers, geometric isomers, regioisomers and
individual isomers (e.g., separate enantiomers) are all intended to
be encompassed within the scope of the present invention.
[0102] The terms "treat" and "treatment" refer to both therapeutic
treatment and/or prophylactic treatment or preventative measures,
wherein the object is to prevent or slow down (lessen) an undesired
physiological change or disorder, such as, for example, the
development or spread of cancer. For purposes of this invention,
beneficial or desired clinical results include, but are not limited
to, alleviation of symptoms, diminishment of extent of disease or
disorder, stabilized (i.e., not worsening) state of disease or
disorder, delay or slowing of disease progression, amelioration or
palliation of the disease state or disorder, and remission (whether
partial or total), whether detectable or undetectable. "Treatment"
can also mean prolonging survival as compared to expected survival
if not receiving treatment. Those in need of treatment include
those already with the disease or disorder as well as those prone
to have the disease or disorder or those in which the disease or
disorder is to be prevented.
[0103] The phrase "therapeutically effective amount" or "effective
amount" means an amount of a compound of the present invention that
(i) treats or prevents the particular disease, condition, or
disorder, (ii) attenuates, ameliorates, or eliminates one or more
symptoms of the particular disease, condition, or disorder, or
(iii) prevents or delays the onset of one or more symptoms of the
particular disease, condition, or disorder described herein. For
cancer therapy, efficacy can, for example, be measured by assessing
the time to disease progression (TTP) and/or determining the
response rate (RR).
[0104] The term "bioavailability" refers to the systemic
availability (i.e., blood/plasma levels) of a given amount of drug
administered to a patient. Bioavailability is an absolute term that
indicates measurement of both the time (rate) and total amount
(extent) of drug that reaches the general circulation from an
administered dosage form.
Compounds
[0105] In one aspect the present invention provides for compounds
of Formula I and its embodiments as described hereinbove.
[0106] In another embodiment, the compound is selected from
compounds of formula I as described in the Examples herein and
salts thereof.
Synthesis of Compounds
[0107] Compounds of formula (I) may be prepared by the process
illustrated in the schemes below.
##STR00027##
##STR00028##
##STR00029##
##STR00030## ##STR00031##
Pharmaceutical Compositions and Administration
[0108] In addition to one or more of the compounds provided above
(or stereoisomers, geometric isomers, tautomers, solvates,
metabolites, isotopes, pharmaceutically acceptable salts, or
prodrugs thereof), the invention also provides for compositions and
medicaments comprising a compound of formula I or and embodiment
thereof and at least one pharmaceutically acceptable carrier,
diluent or excipient. The compositions of the invention can be used
to selectively inhibit NaV1.7 in patients (e.g, humans).
[0109] The term "composition," as used herein, is intended to
encompass a product comprising the specified ingredients in the
specified amounts, as well as any product which results, directly
or indirectly, from combination of the specified ingredients in the
specified amounts. By "pharmaceutically acceptable" it is meant the
carrier, diluent or excipient must be compatible with the other
ingredients of the formulation and not deleterious to the recipient
thereof.
[0110] In one embodiment, the invention provides for pharmaceutical
compositions (or medicaments) comprising a compound of formula I or
an embodiment thereof, and its stereoisomers, geometric isomers,
tautomers, solvates, metabolites, isotopes, pharmaceutically
acceptable salts, or prodrugs thereof) and a pharmaceutically
acceptable carrier, diluent or excipient. In another embodiment,
the invention provides for preparing compositions (or medicaments)
comprising compounds of the invention. In another embodiment, the
invention provides for administering compounds of formula I or its
embodiments and compositions comprising compounds of formula I or
an embodiment thereof to a patient (e.g., a human patient) in need
thereof.
[0111] Compositions are formulated, dosed, and administered in a
fashion consistent with good medical practice. Factors for
consideration in this context include the particular disorder being
treated, the particular mammal being treated, the clinical
condition of the individual patient, the cause of the disorder, the
site of delivery of the agent, the method of administration, the
scheduling of administration, and other factors known to medical
practitioners. The effective amount of the compound to be
administered will be governed by such considerations, and is the
minimum amount necessary to inhibit NaV1.7 activity as required to
prevent or treat the undesired disease or disorder, such as for
example, pain. For example, such amount may be below the amount
that is toxic to normal cells, or the mammal as a whole.
[0112] In one example, the therapeutically effective amount of the
compound of the invention administered parenterally per dose will
be in the range of about 0.01-100 mg/kg, alternatively about e.g.,
0.1 to 20 mg/kg of patient body weight per day, with the typical
initial range of compound used being 0.3 to 15 mg/kg/day. The daily
does is, in certain embodiments, given as a single daily dose or in
divided doses two to six times a day, or in sustained release form.
In the case of a 70 kg adult human, the total daily dose will
generally be from about 7 mg to about 1,400 mg. This dosage regimen
may be adjusted to provide the optimal therapeutic response. The
compounds may be administered on a regimen of 1 to 4 times per day,
preferably once or twice per day.
[0113] The compounds of the present invention may be administered
in any convenient administrative form, e.g., tablets, powders,
capsules, solutions, dispersions, suspensions, syrups, sprays,
suppositories, gels, emulsions, patches, etc. Such compositions may
contain components conventional in pharmaceutical preparations,
e.g., diluents, carriers, pH modifiers, sweeteners, bulking agents,
and further active agents.
[0114] The compounds of the invention may be administered by any
suitable means, including oral, topical (including buccal and
sublingual), rectal, vaginal, transdermal, parenteral,
subcutaneous, intraperitoneal, intrapulmonary, intradermal,
intrathecal and epidural and intranasal, and, if desired for local
treatment, intralesional administration. Parenteral infusions
include intramuscular, intravenous, intraarterial, intraperitoneal,
intracerebral, intraocular, intralesional or subcutaneous
administration.
[0115] The compositions comprising compounds of formula I or an
embodiment thereof are normally formulated in accordance with
standard pharmaceutical practice as a pharmaceutical composition. A
typical formulation is prepared by mixing a compound of the present
invention and a diluent, carrier or excipient. Suitable diluents,
carriers and excipients are well known to those skilled in the art
and are described in detail in, e.g., Ansel, Howard C., et al.,
Ansel's Pharmaceutical Dosage Forms and Drug Delivery Systems.
Philadelphia: Lippincott, Williams & Wilkins, 2004; Gennaro,
Alfonso R., et al. Remington: The Science and Practice of Pharmacy.
Philadelphia: Lippincott, Williams & Wilkins, 2000; and Rowe,
Raymond C. Handbook of Pharmaceutical Excipients. Chicago,
Pharmaceutical Press, 2005. The formulations may also include one
or more buffers, stabilizing agents, surfactants, wetting agents,
lubricating agents, emulsifiers, suspending agents, preservatives,
antioxidants, opaquing agents, glidants, processing aids,
colorants, sweeteners, perfuming agents, flavoring agents, diluents
and other known additives to provide an elegant presentation of the
drug (i.e., a compound of the present invention or pharmaceutical
composition thereof) or aid in the manufacturing of the
pharmaceutical product (i.e., medicament).
[0116] Suitable carriers, diluents and excipients are well known to
those skilled in the art and include materials such as
carbohydrates, waxes, water soluble and/or swellable polymers,
hydrophilic or hydrophobic materials, gelatin, oils, solvents,
water and the like. The particular carrier, diluent or excipient
used will depend upon the means and purpose for which a compound of
the present invention is being applied. Solvents are generally
selected based on solvents recognized by persons skilled in the art
as safe (GRAS) to be administered to a mammal. In general, safe
solvents are non-toxic aqueous solvents such as water and other
non-toxic solvents that are soluble or miscible in water. Suitable
aqueous solvents include water, ethanol, propylene glycol,
polyethylene glycols (e.g., PEG 400, PEG 300), etc. and mixtures
thereof. The formulations can also include one or more buffers,
stabilizing agents, surfactants, wetting agents, lubricating
agents, emulsifiers, suspending agents, preservatives,
antioxidants, opaquing agents, glidants, processing aids,
colorants, sweeteners, perfuming agents, flavoring agents and other
known additives to provide an elegant presentation of the drug
(i.e., a compound of the present invention or pharmaceutical
composition thereof) or aid in the manufacturing of the
pharmaceutical product (i.e., medicament).
[0117] Acceptable diluents, carriers, excipients and stabilizers
are nontoxic to recipients at the dosages and concentrations
employed, and include buffers such as phosphate, citrate and other
organic acids; antioxidants including ascorbic acid and methionine;
preservatives (such as octadecyldimethylbenzyl ammonium chloride;
hexamethonium chloride; benzalkonium chloride, benzethonium
chloride; phenol, butyl or benzyl alcohol; alkyl parabens such as
methyl or propyl paraben; catechol; resorcinol; cyclohexanol;
3-pentanol; and m-cresol); low molecular weight (less than about 10
residues) polypeptides; proteins, such as serum albumin, gelatin,
or immunoglobulins; hydrophilic polymers such as
polyvinylpyrrolidone; amino acids such as glycine, glutamine,
asparagine, histidine, arginine, or lysine; monosaccharides,
disaccharides and other carbohydrates including glucose, mannose,
or dextrins; chelating agents such as EDTA; sugars such as sucrose,
mannitol, trehalose or sorbitol; salt-forming counter-ions such as
sodium; metal complexes (e.g., Zn-protein complexes); and/or
non-ionic surfactants such as TWEEN.TM., PLURONICS.TM. or
polyethylene glycol (PEG). A active pharmaceutical ingredient of
the invention (e.g., compound of formula I or an embodiment
thereof) can also be entrapped in microcapsules prepared, for
example, by coacervation techniques or by interfacial
polymerization, for example, hydroxymethylcellulose or
gelatin-microcapsules and poly-(methylmethacylate) microcapsules,
respectively, in colloidal drug delivery systems (for example,
liposomes, albumin microspheres, microemulsions, nano-particles and
nanocapsules) or in macroemulsions. Such techniques are disclosed
in Remington: The Science and Practice of Pharmacy: Remington the
Science and Practice of Pharmacy (2005) 21.sup.st Edition,
Lippincott Williams & Wilkins, Philadelphia, Pa.
[0118] Sustained-release preparations of a compound of the
invention (e.g., compound of formula I or an embodiment thereof)
can be prepared. Suitable examples of sustained-release
preparations include semipermeable matrices of solid hydrophobic
polymers containing a compound of formula I or an embodiment
thereof, which matrices are in the form of shaped articles, e.g.,
films, or microcapsules. Examples of sustained-release matrices
include polyesters, hydrogels (for example,
poly(2-hydroxyethyl-methacrylate), or poly(vinyl alcohol)),
polylactides (U.S. Pat. No. 3,773,919), copolymers of L-glutamic
acid and gamma-ethyl-L-glutamate (Sidman et al., Biopolymers
22:547, 1983), non-degradable ethylene-vinyl acetate (Langer et
al., J. Biomed. Mater. Res. 15:167, 1981), degradable lactic
acid-glycolic acid copolymers such as the LUPRON DEPOT.TM.
(injectable microspheres composed of lactic acid-glycolic acid
copolymer and leuprolide acetate) and poly-D-(-)-3-hydroxybutyric
acid (EP 133,988A). Sustained release compositions also include
liposomally entrapped compounds, which can be prepared by methods
known per se (Epstein et al., Proc. Natl. Acad. Sci. U.S.A.
82:3688, 1985; Hwang et al., Proc. Natl. Acad. Sci. U.S.A. 77:4030,
1980; U.S. Pat. Nos. 4,485,045 and 4,544,545; and EP 102,324A).
Ordinarily, the liposomes are of the small (about 200-800
Angstroms) unilamelar type in which the lipid content is greater
than about 30 mol % cholesterol, the selected proportion being
adjusted for the optimal therapy.
[0119] The formulations include those suitable for the
administration routes detailed herein. The formulations can
conveniently be presented in unit dosage form and can be prepared
by any of the methods well known in the art of pharmacy. Techniques
and formulations generally are found in Remington: The Science and
Practice of Pharmacy: Remington the Science and Practice of
Pharmacy (2005) 21.sup.st Edition, Lippincott Williams &
Wilkins, Philadelphia, Pa. Such methods include the step of
bringing into association the active ingredient with the carrier
which constitutes one or more accessory ingredients.
[0120] In general the formulations are prepared by uniformly and
intimately bringing into association the active ingredient with
liquid carriers, diluents or excipients or finely divided solid
carriers, diluents or excipients, or both, and then, if necessary,
shaping the product. A typical formulation is prepared by mixing a
compound of the present invention and a carrier, diluent or
excipient. The formulations can be prepared using conventional
dissolution and mixing procedures. For example, the bulk drug
substance (i.e., compound of the present invention or stabilized
form of the compound (e.g., complex with a cyclodextrin derivative
or other known complexation agent) is dissolved in a suitable
solvent in the presence of one or more of the excipients described
above. A compound of the present invention is typically formulated
into pharmaceutical dosage forms to provide an easily controllable
dosage of the drug and to enable patient compliance with the
prescribed regimen.
[0121] In one example, compounds of formula I or an embodiment
thereof may be formulated by mixing at ambient temperature at the
appropriate pH, and at the desired degree of purity, with
physiologically acceptable carriers, i.e., carriers that are
non-toxic to recipients at the dosages and concentrations employed
into a galenical administration form. The pH of the formulation
depends mainly on the particular use and the concentration of
compound, but preferably ranges anywhere from about 3 to about 8.
In one example, a compound of formula I (or an embodiment thereof)
is formulated in an acetate buffer, at pH 5. In another embodiment,
the compounds of formula I or an embodiment thereof are sterile.
The compound may be stored, for example, as a solid or amorphous
composition, as a lyophilized formulation or as an aqueous
solution.
[0122] Formulations of a compound of the invention (e.g., compound
of formula I or an embodiment thereof) suitable for oral
administration can be prepared as discrete units such as pills,
capsules, cachets or tablets each containing a predetermined amount
of a compound of the invention.
[0123] Compressed tablets can be prepared by compressing in a
suitable machine the active ingredient in a free-flowing form such
as a powder or granules, optionally mixed with a binder, lubricant,
inert diluent, preservative, surface active or dispersing agent.
Molded tablets can be made by molding in a suitable machine a
mixture of the powdered active ingredient moistened with an inert
liquid diluent. The tablets can optionally be coated or scored and
optionally are formulated so as to provide slow or controlled
release of the active ingredient therefrom.
[0124] Tablets, troches, lozenges, aqueous or oil suspensions,
dispersible powders or granules, emulsions, hard or soft capsules,
e.g., gelatin capsules, syrups or elixirs can be prepared for oral
use.
[0125] Formulations of a compound of the invention (e.g., compound
of formula I or an embodiment thereof) intended for oral use can be
prepared according to any method known to the art for the
manufacture of pharmaceutical compositions and such compositions
can contain one or more agents including sweetening agents,
flavoring agents, coloring agents and preserving agents, in order
to provide a palatable preparation. Tablets containing the active
ingredient in admixture with non-toxic pharmaceutically acceptable
excipient which are suitable for manufacture of tablets are
acceptable. These excipients can be, for example, inert diluents,
such as calcium or sodium carbonate, lactose, calcium or sodium
phosphate; granulating and disintegrating agents, such as maize
starch, or alginic acid; binding agents, such as starch, gelatin or
acacia; and lubricating agents, such as magnesium stearate, stearic
acid or talc. Tablets can be uncoated or can be coated by known
techniques including microencapsulation to delay disintegration and
adsorption in the gastrointestinal tract and thereby provide a
sustained action over a longer period. For example, a time delay
material such as glyceryl monostearate or glyceryl distearate alone
or with a wax can be employed.
[0126] An example of a suitable oral administration form is a
tablet containing about 1 mg, 5 mg, 10 mg, 25 mg, 30 mg, 50 mg, 80
mg, 100 mg, 150 mg, 250 mg, 300 mg and 500 mg of the compound of
the invention compounded with about 90-30 mg anhydrous lactose,
about 5-40 mg sodium croscarmellose, about 5-30 mg
polyvinylpyrrolidone (PVP) K30, and about 1-10 mg magnesium
stearate. The powdered ingredients are first mixed together and
then mixed with a solution of the PVP. The resulting composition
can be dried, granulated, mixed with the magnesium stearate and
compressed to tablet form using conventional equipment. An example
of an aerosol formulation can be prepared by dissolving the
compound, for example 5-400 mg, of the invention in a suitable
buffer solution, e.g. a phosphate buffer, adding a tonicifier, e.g.
a salt such sodium chloride, if desired. The solution may be
filtered, e.g., using a 0.2 micron filter, to remove impurities and
contaminants.
[0127] For treatment of the eye or other external tissues, e.g.,
mouth and skin, the formulations are preferably applied as a
topical ointment or cream containing the active ingredient(s) in an
amount of, for example, 0.075 to 20% w/w. When formulated in an
ointment, the active ingredient can be employed with either a
paraffinic or a water-miscible ointment base. Alternatively, the
active ingredients can be formulated in a cream with an
oil-in-water cream base. If desired, the aqueous phase of the cream
base can include a polyhydric alcohol, i.e., an alcohol having two
or more hydroxyl groups such as propylene glycol, butane 1,3-diol,
mannitol, sorbitol, glycerol and polyethylene glycol (including PEG
400) and mixtures thereof. The topical formulations can desirably
include a compound which enhances absorption or penetration of the
active ingredient through the skin or other affected areas.
Examples of such dermal penetration enhancers include dimethyl
sulfoxide and related analogs.
[0128] The oily phase of the emulsions of this invention can be
constituted from known ingredients in a known manner. While the
phase can comprise merely an emulsifier, it desirably comprises a
mixture of at least one emulsifier with a fat or an oil or with
both a fat and an oil. Preferably, a hydrophilic emulsifier is
included together with a lipophilic emulsifier which acts as a
stabilizer. It is also preferred to include both an oil and a fat.
Together, the emulsifier(s) with or without stabilizer(s) make up
the so-called emulsifying wax, and the wax together with the oil
and fat make up the so-called emulsifying ointment base which forms
the oily dispersed phase of the cream formulations. Emulsifiers and
emulsion stabilizers suitable for use in the formulation of the
invention include Tween.RTM. 60, Span.RTM. 80, cetostearyl alcohol,
benzyl alcohol, myristyl alcohol, glyceryl mono-stearate and sodium
lauryl sulfate.
[0129] In one aspect of topical applications, it is desired to
administer an effective amount of a pharmaceutical composition
according to the invention to target area, e.g., skin surfaces,
mucous membranes, and the like, which are adjacent to peripheral
neurons which are to be treated. This amount will generally range
from about 0.0001 mg to about 1 g of a compound of the invention
per application, depending upon the area to be treated, whether the
use is diagnostic, prophylactic or therapeutic, the severity of the
symptoms, and the nature of the topical vehicle employed. A
preferred topical preparation is an ointment, wherein about 0.001
to about 50 mg of active ingredient is used per cc of ointment
base. The pharmaceutical composition can be formulated as
transdermal compositions or transdermal delivery devices
("patches"). Such compositions include, for example, a backing,
active compound reservoir, a control membrane, liner and contact
adhesive.
[0130] Such transdermal patches may be used to provide continuous
pulsatile, or on demand delivery of the compounds of the present
invention as desired.
[0131] Aqueous suspensions of a compound of the invention (e.g.,
compound of formula I or an embodiment thereof) contain the active
materials in admixture with excipients suitable for the manufacture
of aqueous suspensions. Such excipients include a suspending agent,
such as sodium carboxymethylcellulose, croscarmellose, povidone,
methylcellulose, hydroxypropyl methylcellulose, sodium alginate,
polyvinylpyrrolidone, gum tragacanth and gum acacia, and dispersing
or wetting agents such as a naturally occurring phosphatide (e.g.,
lecithin), a condensation product of an alkylene oxide with a fatty
acid (e.g., polyoxyethylene stearate), a condensation product of
ethylene oxide with a long chain aliphatic alcohol (e.g.,
heptadecaethyleneoxycetanol), a condensation product of ethylene
oxide with a partial ester derived from a fatty acid and a hexitol
anhydride (e.g., polyoxyethylene sorbitan monooleate). The aqueous
suspension can also contain one or more preservatives such as ethyl
or n-propyl p-hydroxybenzoate, one or more coloring agents, one or
more flavoring agents and one or more sweetening agents, such as
sucrose or saccharin.
[0132] Formulations of a compound of the invention (e.g., compound
of formula I or an embodiment thereof) can be in the form of a
sterile injectable preparation, such as a sterile injectable
aqueous or oleaginous suspension. This suspension can be formulated
according to the known art using those suitable dispersing or
wetting agents and suspending agents which have been mentioned
above. The sterile injectable preparation can also be a sterile
injectable solution or suspension in a non-toxic parenterally
acceptable diluent or solvent, such as a solution in 1,3-butanediol
or prepared as a lyophilized powder. Among the acceptable vehicles
and solvents that can be employed are water, Ringer's solution and
isotonic sodium chloride solution. In addition, sterile fixed oils
can conventionally be employed as a solvent or suspending medium.
For this purpose any bland fixed oil can be employed including
synthetic mono- or diglycerides. In addition, fatty acids such as
oleic acid can likewise be used in the preparation of
injectables.
[0133] The amount of active ingredient that can be combined with
the carrier material to produce a single dosage form will vary
depending upon the host treated and the particular mode of
administration. For example, a time-release formulation intended
for oral administration to humans can contain approximately 1 to
1000 mg of active material compounded with an appropriate and
convenient amount of carrier material which can vary from about 5
to about 95% of the total compositions (weight:weight). The
pharmaceutical composition can be prepared to provide easily
measurable amounts for administration. For example, an aqueous
solution intended for intravenous infusion can contain from about 3
to 500 .mu.g of the active ingredient per milliliter of solution in
order that infusion of a suitable volume at a rate of about 30
mL/hr can occur.
[0134] Formulations suitable for parenteral administration include
aqueous and non-aqueous sterile injection solutions which can
contain anti-oxidants, buffers, bacteriostats and solutes which
render the formulation isotonic with the blood of the intended
recipient; and aqueous and non-aqueous sterile suspensions which
can include suspending agents and thickening agents.
[0135] Formulations suitable for topical administration to the eye
also include eye drops wherein the active ingredient is dissolved
or suspended in a suitable carrier, especially an aqueous solvent
for the active ingredient. The active ingredient is preferably
present in such formulations in a concentration of about 0.5 to 20%
w/w, for example about 0.5 to 10% w/w, for example about 1.5%
w/w.
[0136] Formulations suitable for topical administration in the
mouth include lozenges comprising the active ingredient in a
flavored basis, usually sucrose and acacia or tragacanth; pastilles
comprising the active ingredient in an inert basis such as gelatin
and glycerin, or sucrose and acacia; and mouthwashes comprising the
active ingredient in a suitable liquid carrier.
[0137] Formulations for rectal administration can be presented as a
suppository with a suitable base comprising for example cocoa
butter or a salicylate.
[0138] Formulations suitable for intrapulmonary or nasal
administration have a particle size for example in the range of 0.1
to 500 microns (including particle sizes in a range between 0.1 and
500 microns in increments microns such as 0.5, 1, 30 microns, 35
microns, etc.), which is administered by rapid inhalation through
the nasal passage or by inhalation through the mouth so as to reach
the alveolar sacs. Suitable formulations include aqueous or oily
solutions of the active ingredient.
[0139] Formulations suitable for aerosol or dry powder
administration can be prepared according to conventional methods
and can be delivered with other therapeutic agents such as
compounds heretofore used in the treatment of disorders as
described below.
[0140] The formulations can be packaged in unit-dose or multi-dose
containers, for example sealed ampoules and vials, and can be
stored in a freeze-dried (lyophilized) condition requiring only the
addition of the sterile liquid carrier, for example water, for
injection immediately prior to use.
[0141] Extemporaneous injection solutions and suspensions are
prepared from sterile powders, granules and tablets of the kind
previously described. Preferred unit dosage formulations are those
containing a daily dose or unit daily sub-dose, as herein above
recited, or an appropriate fraction thereof, of the active
ingredient.
[0142] When the binding target is located in the brain, certain
embodiments of the invention provide for a compound of formula I
(or an embodiment thereof) to traverse the blood-brain barrier.
[0143] Certain neurodegenerative diseases are associated with an
increase in permeability of the blood-brain barrier, such that a
compound of formula I (or an embodiment thereof) can be readily
introduced to the brain. When the blood-brain barrier remains
intact, several art-known approaches exist for transporting
molecules across it, including, but not limited to, physical
methods, lipid-based methods, and receptor and channel-based
methods.
[0144] Physical methods of transporting a compound of formula I (or
an embodiment thereof) across the blood-brain barrier include, but
are not limited to, circumventing the blood-brain barrier entirely,
or by creating openings in the blood-brain barrier.
[0145] Circumvention methods include, but are not limited to,
direct injection into the brain (see, e.g., Papanastassiou et al.,
Gene Therapy 9:398-406, 2002), interstitial
infusion/convection-enhanced delivery (see, e.g., Bobo et al.,
Proc. Natl. Acad. Sci. U.S.A. 91:2076-2080, 1994), and implanting a
delivery device in the brain (see, e.g., Gill et al., Nature Med.
9:589-595, 2003; and Gliadel Wafers.TM., Guildford.
[0146] Pharmaceutical). Methods of creating openings in the barrier
include, but are not limited to, ultrasound (see, e.g., U.S. Patent
Publication No. 2002/0038086), osmotic pressure (e.g., by
administration of hypertonic mannitol (Neuwelt, E. A., Implication
of the Blood-Brain Barrier and its Manipulation, Volumes 1 and 2,
Plenum Press, N.Y., 1989)), and permeabilization by, e.g.,
bradykinin or permeabilizer A-7 (see, e.g., U.S. Pat. Nos.
5,112,596, 5,268,164, 5,506,206, and 5,686,416).
[0147] Lipid-based methods of transporting a compound of formula I
(or an embodiment thereof) across the blood-brain barrier include,
but are not limited to, encapsulating the a compound of formula I
(or an embodiment thereof) in liposomes that are coupled to
antibody binding fragments that bind to receptors on the vascular
endothelium of the blood-brain barrier (see, e.g., U.S. Patent
Application Publication No. 2002/0025313), and coating a compound
of formula I (or an embodiment thereof) in low-density lipoprotein
particles (see, e.g., U.S. Patent Application Publication No.
2004/0204354) or apolipoprotein E (see, e.g., U.S. Patent
Application Publication No. 2004/0131692).
[0148] Receptor and channel-based methods of transporting a
compound of formula I (or an embodiment thereof) across the
blood-brain barrier include, but are not limited to, using
glucocorticoid blockers to increase permeability of the blood-brain
barrier (see, e.g., U.S. Patent Application Publication Nos.
2002/0065259, 2003/0162695, and 2005/0124533); activating potassium
channels (see, e.g., U.S. Patent Application Publication No.
2005/0089473), inhibiting ABC drug transporters (see, e.g., U.S.
Patent Application Publication No. 2003/0073713); coating a
compound of formula I (or an embodiment thereof) with a transferrin
and modulating activity of the one or more transferrin receptors
(see, e.g., U.S. Patent Application Publication No. 2003/0129186),
and cationizing the antibodies (see, e.g., U.S. Pat. No.
5,004,697).
[0149] For intracerebral use, in certain embodiments, the compounds
can be administered continuously by infusion into the fluid
reservoirs of the CNS, although bolus injection may be acceptable.
The inhibitors can be administered into the ventricles of the brain
or otherwise introduced into the CNS or spinal fluid.
Administration can be performed by use of an indwelling catheter
and a continuous administration means such as a pump, or it can be
administered by implantation, e.g., intracerebral implantation of a
sustained-release vehicle. More specifically, the inhibitors can be
injected through chronically implanted cannulas or chronically
infused with the help of osmotic minipumps. Subcutaneous pumps are
available that deliver proteins through a small tubing to the
cerebral ventricles. Highly sophisticated pumps can be refilled
through the skin and their delivery rate can be set without
surgical intervention. Examples of suitable administration
protocols and delivery systems involving a subcutaneous pump device
or continuous intracerebroventricular infusion through a totally
implanted drug delivery system are those used for the
administration of dopamine, dopamine agonists, and cholinergic
agonists to Alzheimer's disease patients and animal models for
Parkinson's disease, as described by Harbaugh, J. Neural Transm.
Suppl. 24:271, 1987; and DeYebenes et al., Mov. Disord. 2: 143,
1987.
[0150] A compound of formula I (or an embodiment thereof) used in
the invention are formulated, dosed, and administered in a fashion
consistent with good medical practice. Factors for consideration in
this context include the particular disorder being treated, the
particular mammal being treated, the clinical condition of the
individual patient, the cause of the disorder, the site of delivery
of the agent, the method of administration, the scheduling of
administration, and other factors known to medical practitioners. A
compound of formula I (or an embodiment thereof) need not be, but
is optionally formulated with one or more agent currently used to
prevent or treat the disorder in question. The effective amount of
such other agents depends on the amount of a compound of the
invention present in the formulation, the type of disorder or
treatment, and other factors discussed above.
[0151] These are generally used in the same dosages and with
administration routes as described herein, or about from 1 to 99%
of the dosages described herein, or in any dosage and by any route
that is empirically/clinically determined to be appropriate.
[0152] For the prevention or treatment of disease, the appropriate
dosage of a compound of formula I (or an embodiment thereof) (when
used alone or in combination with other agents) will depend on the
type of disease to be treated, the properties of the compound, the
severity and course of the disease, whether the compound is
administered for preventive or therapeutic purposes, previous
therapy, the patient's clinical history and response to the
compound, and the discretion of the attending physician. The
compound is suitably administered to the patient at one time or
over a series of treatments. Depending on the type and severity of
the disease, about 1 .mu.g/kg to 15 mg/kg (e.g., 0.1 mg/kg-10
mg/kg) of compound can be an initial candidate dosage for
administration to the patient, whether, for example, by one or more
separate administrations, or by continuous infusion. One typical
daily dosage might range from about 1 .mu.g kg to 100 mg/kg or
more, depending on the factors mentioned above. For repeated
administrations over several days or longer, depending on the
condition, the treatment would generally be sustained until a
desired suppression of disease symptoms occurs. One exemplary
dosage of a compound of formula I (or an embodiment thereof) would
be in the range from about 0.05 mg/kg to about 10 mg/kg. Thus, one
or more doses of about 0.5 mg/kg, 2.0 mg/kg, 4.0 mg/kg, or 10 mg/kg
(or any combination thereof) may be administered to the patient.
Such doses may be administered intermittently, e.g., every week or
every three weeks (e.g., such that the patient receives from about
two to about twenty, or, e.g., about six doses of the antibody). An
initial higher loading dose, followed by one or more lower doses
may be administered. An exemplary dosing regimen comprises
administering an initial loading dose of about 4 mg/kg, followed by
a weekly maintenance dose of about 2 mg kg of the compound.
However, other dosage regimens may be useful. The progress of this
therapy is easily monitored by conventional techniques and
assays.
[0153] Other typical daily dosages might range from, for example,
about 1 g/kg to up to 100 mg/kg or more (e.g., about 1 .mu.g kg to
1 mg/kg, about 1 .mu.g/kg to about 5 mg/kg, about 1 mg kg to 10
mg/kg, about 5 mg/kg to about 200 mg/kg, about 50 mg/kg to about
150 mg/mg, about 100 mg/kg to about 500 mg/kg, about 100 mg/kg to
about 400 mg/kg, and about 200 mg/kg to about 400 mg/kg), depending
on the factors mentioned above. Typically, the clinician will
administer a compound until a dosage is reached that results in
improvement in or, optimally, elimination of, one or more symptoms
of the treated disease or condition. The progress of this therapy
is easily monitored by conventional assays. One or more agent
provided herein may be administered together or at different times
(e.g., one agent is administered prior to the administration of a
second agent). One or more agent may be administered to a subject
using different techniques (e.g., one agent may be administered
orally, while a second agent is administered via intramuscular
injection or intranasally). One or more agent may be administered
such that the one or more agent has a pharmacologic effect in a
subject at the same time. Alternatively, one or more agent may be
administered, such that the pharmacological activity of the first
administered agent is expired prior the administration of one or
more secondarily administered agents (e.g., 1, 2, 3, or 4
secondarily administered agents).
Indications and Methods of Treatment
[0154] The compounds of the invention modulate, preferably inhibit,
ion flux through a voltage-dependent sodium channel in a mammal,
(e.g, a human). Any such modulation, whether it be partial or
complete inhibition or prevention of ion flux, is sometimes
referred to herein as "blocking" and corresponding compounds as
"blockers" or "inhibitors". In general, the compounds of the
invention modulate the activity of a sodium channel downwards by
inhibiting the voltage-dependent activity of the sodium channel,
and/or reduce or prevent sodium ion flux across a cell membrane by
preventing sodium channel activity such as ion flux.
[0155] Accordingly, the compounds of the invention are sodium
channel blockers and are therefore useful for treating diseases and
conditions in mammals, for example humans, and other organisms,
including all those diseases and conditions which are the result of
aberrant voltage-dependent sodium channel biological activity or
which may be ameliorated by modulation of voltage-dependent sodium
channel biological activity. In particular, the compounds of the
invention, i.e., the compounds of formula (I) and embodiments and
(or stereoisomers, geometric isomers, tautomers, solvates,
metabolites, isotopes, pharmaceutically acceptable salts, or
prodrugs thereof), are useful for treating diseases and conditions
in mammals, for example humans, which are the result of aberrant
voltage-dependent NaV1.7 biological activity or which may be
ameliorated by the modulation, preferably the inhibition, of NaV1.7
biological activity. In certain aspects, the compounds of the
invention selectively inhibit NaV1.7 over NaV1.5.
[0156] As defined herein, a sodium channel-mediated disease or
condition refers to a disease or condition in a mammal, preferably
a human, which is ameliorated upon modulation of the sodium channel
and includes, but is not limited to, pain, central nervous
conditions such as epilepsy, anxiety, depression and bipolar
disease; cardiovascular conditions such as arrhythmias, atrial
fibrillation and ventricular fibrillation; neuromuscular conditions
such as restless leg syndrome and muscle paralysis or tetanus;
neuroprotection against stroke, neural trauma and multiple
sclerosis; and channelopathies such as erythromyalgia and familial
rectal pain syndrome.
[0157] In one aspect, the present invention relates to compounds,
pharmaceutical compositions and methods of using the compounds and
pharmaceutical compositions for the treatment of sodium
channel-mediated diseases in mammals, preferably humans and
preferably diseases and conditions related to pain, central nervous
conditions such as epilepsy, anxiety, depression and bipolar
disease; cardiovascular conditions such as arrhythmias, atrial
fibrillation and ventricular fibrillation; neuromuscular conditions
such as restless leg syndrome and muscle paralysis or tetanus;
neuroprotection against stroke, neural trauma and multiple
sclerosis; and channelopathies such as erythromyalgia and familial
rectal pain syndrome, by administering to a mammal, for example a
human, in need of such treatment an effective amount of a sodium
channel blocker modulating, especially inhibiting, agent.
[0158] A sodium channel-mediated disease or condition also includes
pain associated with HIV, HIV treatment induced neuropathy,
trigeminal neuralgia, glossopharyngeal neuralgia, neuropathy
secondary to metastatic infiltration, adiposis dolorosa, thalamic
lesions, hypertension, autoimmune disease, asthma, drug addiction
(e.g., opiate, benzodiazepine, amphetamine, cocaine, alcohol,
butane inhalation), Alzheimer, dementia, age-related memory
impairment, Korsakoff syndrome, restenosis, urinary dysfunction,
incontinence, Parkinson's disease, cerebrovascular ischemia,
neurosis, gastrointestinal disease, sickle cell anemia, transplant
rejection, heart failure, myocardial infarction, reperfusion
injury, intermittant claudication, angina, convulsion, respiratory
disorders, cerebral or myocardial ischemias, long-QT syndrome,
Catecholeminergic polymorphic ventricular tachycardia, ophthalmic
diseases, spasticity, spastic paraplegia, myopathies, myasthenia
gravis, paramyotonia congentia, hyperkalemic periodic paralysis,
hypokalemic periodic paralysis, alopecia, anxiety disorders,
psychotic disorders, mania, paranoia, seasonal affective disorder,
panic disorder, obsessive compulsive disorder (OCD), phobias,
autism, Aspergers Syndrome, Retts syndrome, disintegrative
disorder, attention deficit disorder, aggressivity, impulse control
disorders, thrombosis, pre clampsia, congestive cardiac failure,
cardiac arrest, Freidrich's ataxia, Spinocerebellear ataxia,
myelopathy, radiculopathy, systemic lupus erythamatosis,
granulomatous disease, olivo-ponto-cerebellar atrophy,
spinocerebellar ataxia, episodic ataxia, myokymia, progressive
pallidal atrophy, progressive supranuclear palsy and spasticity,
traumatic brain injury, cerebral oedema, hydrocephalus injury,
spinal cord injury, anorexia nervosa, bulimia, Prader-Willi
syndrome, obesity, optic neuritis, cataract, retinal haemorrhage,
ischaemic retinopathy, retinitis pigmentosa, acute and chronic
glaucoma, macular degeneration, retinal artery occlusion, Chorea,
Huntington's chorea, cerebral edema, proctitis, post-herpetic
neuralgia, eudynia, heat sensitivity, sarcoidosis, irritable bowel
syndrome, Tourette syndrome, Lesch-Nyhan Syndrome, Brugado
syndrome, Liddle syndrome, Crohns disease, multiple sclerosis and
the pain associated with multiple sclerosis (MS), amyotrophic
lateral sclerosis (ALS), disseminated sclerosis, diabetic
neuropathy, peripheral neuropathy, charcot marie tooth syndrome,
arthritic, rheumatoid arthritis, osteoarthritis, chondrocalcinosis,
atherosclerosis, paroxysmal dystonia, myasthenia syndromes,
myotonia, myotonic dystrophy, muscular dystrophy, malignant
hyperthermia, cystic fibrosis, pseudoaldosteronism, rhabdomyolysis,
mental handicap, hypothyroidism, bipolar depression, anxiety,
schizophrenia, sodium channel toxin related illnesses, familial
erythromelalgia, primary erythromelalgia, rectal pain, cancer,
epilepsy, partial and general tonic seizures, febrile seizures,
absence seizures (petit mal), myoclonic seizures, atonic seizures,
clonic seizures, Lennox Gastaut, West Syndome (infantile spasms),
multiresistant seizures, seizure prophylaxis (anti-epileptogenic),
familial Mediterranean fever syndrome, gout, restless leg syndrome,
arrhythmias, fibromyalgia, neuroprotection under ischaemic
conditions caused by stroke or neural trauma, tachy-arrhythmias,
atrial fibrillation and ventricular fibrillation and as a general
or local anaesthetic.
[0159] As used herein, the term "pain" refers to all categories of
pain and is recognized to include, but is not limited to,
neuropathic pain, inflammatory pain, nociceptive pain, idiopathic
pain, neuralgic pain, orofacial pain, burn pain, burning mouth
syndrome, somatic pain, visceral pain, myofacial pain, dental pain,
cancer pain, chemotherapy pain, trauma pain, surgical pain,
post-surgical pain, childbirth pain, labor pain, chronic regional
pain syndrome (CRPS), reflex sympathetic dystrophy, brachial plexus
avulsion, neurogenic bladder, acute pain (e.g., musculoskeletal and
post-operative pain), chronic pain, persistent pain, peripherally
mediated pain, centrally mediated pain, chronic headache, migraine
headache, familial hemiplegic migraine, conditions associated with
cephalic pain, sinus headache, tension headache, phantom limb pain,
peripheral nerve injury, pain following stroke, thalamic lesions,
radiculopathy, HIV pain, post-herpetic pain, non-cardiac chest
pain, irritable bowel syndrome and pain associated with bowel
disorders and dyspepsia, and combinations thereof.
[0160] Furthermore, sodium channel blockers have clinical uses in
addition to pain. The present invention therefore also relates to
compounds, pharmaceutical compositions and methods of using the
compounds and pharmaceutical compositions for the treatment of
diseases or conditions such as cancer and pruritus (itch).
[0161] Pruritus, commonly known as itch, is a common dermatological
condition. While the exact causes of pruritus are complex and
incompletely understood, there has long been evidence that itch
involves sensory neurons, especially C fibers, similar to those
that mediate pain (Schmelz, M., et al., J. Neurosci. (1997), 17:
8003-8). In particular, it is believed that sodium influx through
voltage-gated sodium channels is essential for the propagation of
itch sensation from the skin. Transmission of the itch impulses
results in the unpleasant sensation that elicits the desire or
reflex to scratch.
[0162] Multiple causes and electrical pathways for eliciting itch
are known. In humans, pruritis can be elicited by histamine or
PAR-2 agonists such as mucunain that activate distinct populations
of C fibers (Namer, B., et al., J. Neurophysiol. (2008), 100:
2062-9). A variety of neurotrophic peptides are known to mediate
itch in animal models (Wang, H., and Yosipovitch, G., International
Journal of Dermatology (2010), 49: 1-11). Itch can also be elicited
by opioids, evidence of distinct pharmacology from that of pain
responses.
[0163] There exists a complex interaction between itch and pain
responses that arises in part from the overlapping sensory input
from the skin (Ikoma, A., et al., Arch. Dermatol. (2003), 139:
1475-8) and also from the diverse etiology of both pain and
pruritis. Pain responses can exacerbate itching by enhancing
central sensitization or lead to inhibition of painful scratching.
Particularly severe forms of chronic itch occur when pain responses
are absent, as in the case of post-herpetic itch (Oaklander, A. L.,
et al., Pain (2002), 96: 9-12).
[0164] The compounds of the invention can also be useful for
treating pruritus. The rationale for treating itch with inhibitors
of voltage-gated sodium channels, especially NaV1.7, is as follows:
The propagation of electrical activity in the C fibers that sense
pruritinergic stimulants requires sodium entry through
voltage-gated sodium channels.
[0165] NaV1.7 is expressed in the C fibers and kerotinocytes in
human skin (Zhao, P., et al., Pain (2008), 139: 90-105).
[0166] A gain of function mutation of NaV1.7 (L858F) that causes
erythromelalgia also causes chronic itch (Li, Y., et al., Clinical
and Experimental Dermatology (2009), 34: e313-e4).
[0167] Chronic itch can be alleviated with treatment by sodium
channel blockers, such as the local anesthetic lidocaine
(Oaklander, A. L., et al., Pain (2002), 96: 9-12; Villamil, A. G.,
et al., The American Journal of Medicine (2005), 118: 1160-3). In
these reports, lidocaine was effective when administered either
intravenously or topically (a Lidoderm patch). Lidocaine can have
multiple activities at the plasma concentrations achieved when
administered systemically, but when administered topically, the
plasma concentrations are only about 1 .mu.M (Center for Drug
Evaluation and Research NDA 20-612). At these concentrations,
lidocaine is selective for sodium channel block and inhibits
spontaneous electrical activity in C fibers and pain responses in
animal models (Xiao, W. H., and Bennett, G. J. Pain (2008), 137:
218-28). The types of itch or skin irritation, include, but are not
limited to:
[0168] psoriatic pruritus, itch due to hemodyalisis, aguagenic
pruritus, and itching caused by skin disorders (e.g., contact
dermatitis), systemic disorders, neuropathy, psychogenic factors or
a mixture thereof;
[0169] itch caused by allergic reactions, insect bites,
hypersensitivity (e.g., dry skin, acne, eczema, psoriasis),
inflammatory conditions or injury;
[0170] itch associated with vulvar vestibulitis; and
[0171] skin irritation or inflammatory effect from administration
of another therapeutic such as, for example, antibiotics,
antivirals and antihistamines.
[0172] The compounds of the invention are also useful in treating
certain cancers, such as hormone sensitive cancers, such as
prostate cancer (adenocarcinoma), breast cancer, ovarian cancer,
testicular cancer and thyroid neoplasia, in a mammal, preferably a
human. The voltage gated sodium channels have been demonstrated to
be expressed in prostate and breast cancer cells. Up-regulation of
neonatal NaV1.5 occurs as an integral part of the metastatic
process in human breast cancer and could serve both as a novel
marker of the metastatic phenotype and a therapeutic target (Clin.
Cancer Res. (2005), August 1; 11(15): 5381-9). Functional
expression of voltage-gated sodium channel alpha-subunits,
specifically NaV1.7, is associated with strong metastatic potential
in prostate cancer (CaP) in vitro. Voltage-gated sodium channel
alpha-subunits immunostaining, using antibodies specific to the
sodium channel alpha subunit was evident in prostatic tissues and
markedly stronger in CaP vs non-CaP patients (Prostate Cancer
Prostatic Dis., 2005; 8(3):266-73). See also Diss, J. K. J., et
al., Mol. Cell. Neurosci. (2008), 37:537-547 and Kis-Toth, K., et
al., The Journal of Immunology (2011), 187:1273-1280.
[0173] In consideration of the above, in one embodiment, the
present invention provides a method for treating a mammal for, or
protecting a mammal from developing, a sodium channel-mediated
disease, especially pain, comprising administering to the mammal,
especially a human, in need thereof, a therapeutically effective
amount of a compound of the invention or a pharmaceutical
composition comprising a therapeutically effective amount of a
compound of the invention wherein the compound modulates the
activity of one or more voltage-dependent sodium channels.
[0174] In another embodiment of the invention is a method of
treating a disease or a condition in a mammal, preferably a human,
wherein the disease or condition is selected from the group
consisting of pain, depression, cardiovascular diseases,
respiratory diseases, and psychiatric diseases, and combinations
thereof, and wherein the method comprises administering to the
mammal in need thereof a therapeutically effective amount of an
embodiment of a compound of the invention, as set forth above, as a
stereoisomer, enantiomer or tautomer thereof or mixtures thereof,
or a pharmaceutically acceptable salt, solvate or prodrug thereof,
or a pharmaceutical composition comprising a therapeutically
effective amount of a compound of the invention, as set forth
above, as a stereoisomer, enantiomer or tautomer thereof or
mixtures thereof, or a pharmaceutically acceptable salt, solvate or
prodrug thereof, and a pharmaceutically acceptable excipient.
[0175] One embodiment of this embodiment is wherein the disease or
condition is selected from the group consisting of acute pain,
chronic pain, neuropathic pain, inflammatory pain, visceral pain,
cancer pain, chemotherapy pain, trauma pain, surgical pain, post
surgical pain, childbirth pain, labor pain, neurogenic bladder,
ulcerative colitis, persistent pain, peripherally mediated pain,
centrally mediated pain, chronic headache, migraine headache, sinus
headache, tension headache, phantom limb pain, peripheral nerve
injury, and combinations thereof.
[0176] Another embodiment of this embodiment is wherein the disease
or condition is selected from the group consisting of pain
associated with HIV, HIV treatment induced neuropathy, trigeminal
neuralgia, post herpetic neuralgia, eudynia, heat sensitivity,
tosarcoidosis, irritable bowel syndrome, Crohns disease, pain
associated with multiple sclerosis (MS), amyotrophic lateral
sclerosis (ALS), diabetic neuropathy, peripheral neuropathy,
arthritic, rheumatoid arthritis, osteoarthritis, atherosclerosis,
paroxysmal dystonia, myasthenia syndromes, myotonia, malignant
hyperthermia, cystic fibrosis, pseudoaldosteronism, rhabdomyolysis,
hypothyroidism, bipolar depression, anxiety, schizophrenia, sodium
channel toxin related illnesses, familial erythromelalgia, primary
erythromelalgia, familial rectal pain, cancer, epilepsy, partial
and general tonic seizures, restless leg syndrome, arrhythmias,
fibromyalgia, neuroprotection under ischaemic conditions caused by
stroke or neural trauma, tachy arrhythmias, atrial fibrillation and
ventricular fibrillation.
[0177] Another embodiment of the invention is a method of treating,
but not preventing, pain in a mammal, wherein the method comprises
administering to the mammal in need thereof a therapeutically
effective amount of a compound of the invention, as set forth
above, as a stereoisomer, enantiomer or tautomer thereof or
mixtures thereof, or a pharmaceutically acceptable salt, solvate or
prodrug thereof, or a pharmaceutical composition comprising a
therapeutically effective amount of a compound of the invention, as
set forth above, as a stereoisomer, enantiomer or tautomer thereof
or mixtures thereof, or a pharmaceutically acceptable salt, solvate
or prodrug thereof, and a pharmaceutically acceptable
excipient.
[0178] One embodiment of this embodiment is a method wherein the
pain is selected from the group consisting of neuropathic pain,
inflammatory pain, visceral pain, cancer pain, chemotherapy pain,
trauma pain, surgical pain, post surgical pain, childbirth pain,
labor pain, dental pain, chronic pain, persistent pain,
peripherally mediated pain, centrally mediated pain, chronic
headache, migraine headache, sinus headache, tension headache,
phantom limb pain, peripheral nerve injury, trigeminal neuralgia,
post herpetic neuralgia, eudynia, familial erythromelalgia, primary
erythromelalgia, familial rectal pain or fibromyalgia, and
combinations thereof.
[0179] Another embodiment of this embodiment is a method wherein
the pain is associated with a disease or condition selected from
HIV, HIV treatment induced neuropathy, heat sensitivity,
tosarcoidosis, irritable bowel syndrome, Crohns disease, multiple
sclerosis, amyotrophic lateral sclerosis, diabetic neuropathy,
peripheral neuropathy, rheumatoid arthritis, osteoarthritis,
atherosclerosis, paroxysmal dystonia, myasthenia syndromes,
myotonia, malignant hyperthermia, cystic fibrosis,
pseudoaldosteronism, rhabdomyolysis, hypothyroidism, bipolar
depression, anxiety, schizophrenia, sodium channel toxin related
illnesses, neurogenic bladder, ulcerative colitis, cancer,
epilepsy, partial and general tonic seizures, restless leg
syndrome, arrhythmias, ischaemic conditions caused by stroke or
neural trauma, tachy arrhythmias, atrial fibrillation and
ventricular fibrillation.
[0180] Another embodiment of the invention is the method of
treating pain in a mammal, preferably a human, by the inhibition of
ion flux through a voltage dependent sodium channel in the mammal,
wherein the method comprises administering to the mammal in need
thereof a therapeutically effective amount of an embodiment of a
compound of the invention, as set forth above, as a stereoisomer,
enantiomer or tautomer thereof or mixtures thereof, or a
pharmaceutically acceptable salt, solvate or prodrug thereof, or a
pharmaceutical composition comprising a therapeutically effective
amount of a compound of the invention, as set forth above, as a
stereoisomer, enantiomer or tautomer thereof or mixtures thereof,
or a pharmaceutically acceptable salt, solvate or prodrug thereof,
and a pharmaceutically acceptable excipient.
[0181] Another embodiment of the invention is the method of
treating pruritus in a mammal, preferably a human, wherein the
method comprises administering to the mammal in need thereof a
therapeutically effective amount of an embodiment of a compound of
the invention, as set forth above, as a stereoisomer, enantiomer or
tautomer thereof or mixtures thereof, or a pharmaceutically
acceptable salt, solvate or prodrug thereof, or a pharmaceutical
composition comprising a therapeutically effective amount of a
compound of the invention, as set forth above, as a stereoisomer,
enantiomer or tautomer thereof or mixtures thereof, or a
pharmaceutically acceptable salt, solvate or prodrug thereof, and a
pharmaceutically acceptable excipient.
[0182] Another embodiment of the invention is the method of
treating cancer in a mammal, preferably a human, wherein the method
comprises administering to the mammal in need thereof a
therapeutically effective amount of an embodiment of a compound of
the invention, as set forth above, as a stereoisomer, enantiomer or
tautomer thereof or mixtures thereof, or a pharmaceutically
acceptable salt, solvate or prodrug thereof, or a pharmaceutical
composition comprising a therapeutically effective amount of a
compound of the invention, as set forth above, as a stereoisomer,
enantiomer or tautomer thereof or mixtures thereof, or a
pharmaceutically acceptable salt, solvate or prodrug thereof, and a
pharmaceutically acceptable excipient.
[0183] Another embodiment of the invention is the method of
decreasing ion flux through a voltage dependent sodium channel in a
cell in a mammal, wherein the method comprises contacting the cell
with an embodiment of a compound of the invention, as set forth
above, as a stereoisomer, enantiomer or tautomer thereof or
mixtures thereof, or a pharmaceutically acceptable salt, solvate or
prodrug thereof.
[0184] Another embodiment of the invention is the method of
selectively inhibiting a first voltage-gated sodium channel over a
second voltage-gated sodium channel in a mammal, wherein the method
comprises administering to the mammal an inhibitory amount of a
compound of formula (I), or an embodiment of a compound of formula
(I).
[0185] Another embodiment of the invention is the method of
selectively inhibiting NaV1.7 in a mammal or a mammalian cell as
compared to NaV1.5, wherein the method comprises administering to
the mammal in need thereof an inhibitory amount of a compound of
formula (I) or an embodiment of an embodiment thereof.
[0186] For each of the above embodiments described related to
treating diseases and conditions in a mammal, the present invention
also contemplates relatedly a compound of formula I or an
embodiment thereof for the use as a medicament in the treatment of
such diseases and conditions.
[0187] For each of the above embodiments described related to
treating diseases and conditions in a mammal, the present invention
also contemplates relatedly the use of a compound of formula I or
an embodiment thereof for the manufacture of a medicament for the
treatment of such diseases and conditions.
[0188] Another embodiment of the invention is a method of using the
compounds of formula (I) as standards or controls in in vitro or in
vivo assays in determining the efficacy of test compounds in
modulating voltage-dependent sodium channels.
[0189] In another embodiment of the invention, the compounds of
formula (I) are isotopically-labeled by having one or more atoms
therein replaced by an atom having a different atomic mass or mass
number. Such isotopically-labeled (i.e., radiolabelled) compounds
of formula (I) are considered to be within the scope of this
invention. Examples of isotopes that can be incorporated into the
compounds of formula (I) include isotopes of hydrogen, carbon,
nitrogen, oxygen, phosphorous, sulfur, fluorine, chlorine, and
iodine, such as, but not limited to, .sup.2H, .sup.3H, .sup.11C,
.sup.13C, .sup.14C, .sup.13N, .sup.15N, .sup.15O, .sup.17O,
.sup.18O, .sup.31P, .sup.32P, .sup.35S, .sup.18F, .sup.36Cl,
.sup.123I, and .sup.125I, respectively. These isotopically-labeled
compounds would be useful to help determine or measure the
effectiveness of the compounds, by characterizing, for example, the
site or mode of action on the sodium channels, or binding affinity
to pharmacologically important site of action on the sodium
channels, particularly NaV1.7. Certain isotopically-labeled
compounds of formula (I), for example, those incorporating a
radioactive isotope, are useful in drug and/or substrate tissue
distribution studies. The radioactive isotopes tritium, i.e.
.sup.3H, and carbon-14, i.e., .sup.14C, are particularly useful for
this purpose in view of their ease of incorporation and ready means
of detection.
[0190] Substitution with heavier isotopes such as deuterium, i.e.
.sup.2H, may afford certain therapeutic advantages resulting from
greater metabolic stability, for example, increased in vivo
half-life or reduced dosage requirements, and hence may be
preferred in some circumstances.
[0191] Substitution with positron emitting isotopes, such as
.sup.11C, .sup.18F, .sup.15O and .sup.13N, can be useful in
Positron Emission Topography (PET) studies for examining substrate
receptor occupancy. Isotopically-labeled compounds of formula (I)
can generally be prepared by conventional techniques known to those
skilled in the art or by processes analogous to those described in
the Examples as set out below using an appropriate
isotopically-labeled reagent in place of the non-labeled reagent
previously employed.
Testing Compounds
[0192] The assessment of the compounds of the invention in
mediating, especially inhibiting, the sodium channel ion flux can
be determined using the assays described hereinbelow.
Alternatively, the assessment of the compounds in treating
conditions and diseases in humans may be established in industry
standard animal models for demonstrating the efficacy of compounds
in treating pain. Animal models of human neuropathic pain
conditions have been developed that result in reproducible sensory
deficits (allodynia, hyperalgesia, and spontaneous pain) over a
sustained period of time that can be evaluated by sensory testing.
By establishing the degree of mechanical, chemical, and temperature
induced allodynia and hyperalgesia present, several
physiopathological conditions observed in humans can be modeled
allowing the evaluation of pharmacotherapies.
[0193] In rat models of peripheral nerve injury, ectopic activity
in the injured nerve corresponds to the behavioural signs of pain.
In these models, intravenous application of the sodium channel
blocker and local anesthetic lidocaine can suppress the ectopic
activity and reverse the tactile allodynia at concentrations that
do not affect general behaviour and motor function (Mao, J. and
Chen, L. L, Pain (2000), 87:7-17). Allometric scaling of the doses
effective in these rat models, translates into doses similar to
those shown to be efficacious in humans (Tanelian, D. L. and Brose,
W. G., Anesthesiology (1991), 74(5):949-951). Furthermore,
Lidoderm.RTM., lidocaine applied in the form of a dermal patch, is
currently an FDA approved treatment for post-herpetic neuralgia
(Devers, A. and Glaler, B. S., Clin. J. Pain (2000),
16(3):205-8).
[0194] The present invention readily affords many different means
for identification of sodium channel modulating agents that are
useful as therapeutic agents. Identification of modulators of
sodium channel can be assessed using a variety of in vitro and in
vivo assays, e.g., measuring current, measuring membrane potential,
measuring ion flux, (e.g., sodium or guanidinium), measuring sodium
concentration, measuring second messengers and transcription
levels, and using e.g., voltage-sensitive dyes, radioactive
tracers, and patch-clamp electrophysiology.
[0195] One such protocol involves the screening of chemical agents
for ability to modulate the activity of a sodium channel thereby
identifying it as a modulating agent.
[0196] A typical assay described in Bean et al., J. General
Physiology (1983), 83:613-642, and Leuwer, M., et al., Br. J.
Pharmacol (2004), 141(1):47-54, uses patch-clamp techniques to
study the behaviour of channels. Such techniques are known to those
skilled in the art, and may be developed, using current
technologies, into low or medium throughput assays for evaluating
compounds for their ability to modulate sodium channel
behaviour.
[0197] Throughput of test compounds is an important consideration
in the choice of screening assay to be used. In some strategies,
where hundreds of thousands of compounds are to be tested, it is
not desirable to use low throughput means. In other cases, however,
low throughput is satisfactory to identify important differences
between a limited number of compounds. Often it will be necessary
to combine assay types to identify specific sodium channel
modulating compounds.
[0198] Electrophysiological assays using patch clamp techniques is
accepted as a gold standard for detailed characterization of sodium
channel compound interactions, and as described in Bean et al., op.
cit. and Leuwer, M., et al., op. cit. There is a manual
low-throughput screening (LTS) method which can compare 2-10
compounds per day; a recently developed system for automated
medium-throughput screening (MTS) at 20-50 patches (i.e. compounds)
per day; and a technology from Molecular Devices Corporation
(Sunnyvale, Calif.) which permits automated high-throughput
screening (HTS) at 1000-3000 patches (i.e. compounds) per day.
[0199] One automated patch-clamp system utilizes planar electrode
technology to accelerate the rate of drug discovery. Planar
electrodes are capable of achieving high-resistance, cells-attached
seals followed by stable, low-noise whole-cell recordings that are
comparable to conventional recordings. A suitable instrument is the
PatchXpress 7000A (Axon Instruments Inc, Union City, Calif.). A
variety of cell lines and culture techniques, which include
adherent cells as well as cells growing spontaneously in suspension
are ranked for seal success rate and stability. Immortalized cells
(e.g. HEK and CHO) stably expressing high levels of the relevant
sodium ion channel can be adapted into high-density suspension
cultures.
[0200] Other assays can be selected which allow the investigator to
identify compounds which block specific states of the channel, such
as the open state, closed state or the resting state, or which
block transition from open to closed, closed to resting or resting
to open. Those skilled in the art are generally familiar with such
assays.
[0201] Binding assays are also available. Designs include
traditional radioactive filter based binding assays or the confocal
based fluorescent system available from Evotec OAI group of
companies (Hamburg, Germany), both of which are HTS.
[0202] Radioactive flux assays can also be used. In this assay,
channels are stimulated to open with veratridine or aconitine and
held in a stabilized open state with a toxin, and channel blockers
are identified by their ability to prevent ion influx. The assay
can use radioactive 22[Na] and 14[C] guanidinium ions as tracers.
FlashPlate & Cytostar-T plates in living cells avoids
separation steps and are suitable for HTS. Scintillation plate
technology has also advanced this method to HTS suitability.
Because of the functional aspects of the assay, the information
content is reasonably good.
[0203] Yet another format measures the redistribution of membrane
potential using the FLIPR system membrane potential kit (HTS)
available from Molecular Dynamics (a division of Amersham
Biosciences, Piscataway, N.J.). This method is limited to slow
membrane potential changes. Some problems may result from the
fluorescent background of compounds. Test compounds may also
directly influence the fluidity of the cell membrane and lead to an
increase in intracellular dye concentrations. Still, because of the
functional aspects of the assay, the information content is
reasonably good.
[0204] Sodium dyes can be used to measure the rate or amount of
sodium ion influx through a channel. This type of assay provides a
very high information content regarding potential channel blockers.
The assay is functional and would measure Na+ influx directly.
CoroNa Red, SBFI and/or sodium green (Molecular Probes, Inc. Eugene
Oreg.) can be used to measure Na influx; all are Na responsive
dyes. They can be used in combination with the FLIPR instrument.
The use of these dyes in a screen has not been previously described
in the literature. Calcium dyes may also have potential in this
format.
[0205] In another assay, FRET based voltage sensors are used to
measure the ability of a test compound to directly block Na influx.
Commercially available HTS systems include the VIPR.TM. II FRET
system (Life Technologies, or Aurora Biosciences Corporation, San
Diego, Calif., a division of Vertex Pharmaceuticals, Inc.) which
may be used in conjunction with FRET dyes, also available from
Aurora Biosciences. This assay measures sub-second responses to
voltage changes. There is no requirement for a modifier of channel
function. The assay measures depolarization and hyperpolarizations,
and provides ratiometric outputs for quantification. A somewhat
less expensive MTS version of this assay employs the
FLEXstation.TM. (Molecular Devices Corporation) in conjunction with
FRET dyes from Aurora Biosciences. Other methods of testing the
compounds disclosed herein are also readily known and available to
those skilled in the art.
[0206] Modulating agents so identified are then tested in a variety
of in vivo models so as to determine if they alleviate pain,
especially chronic pain or other conditions such as cancer and
pruritus (itch) with minimal adverse events. The assays described
below in the Biological Assays Section are useful in assessing the
biological activity of the instant compounds.
[0207] Typically, the efficacy of a compound of the invention is
expressed by its IC50 value ("Inhibitory Concentration--50%"),
which is the measure of the amount of compound required to achieve
50% inhibition of the activity of the target sodium channel over a
specific time period. For example, representative compounds of the
present invention have demonstrated IC50's ranging from less than
100 nanomolar to less than 10 micromolar in the patch voltage clamp
NaV1.7 electrophysiology assay described herein.
[0208] In another aspect of the invention, the compounds of the
invention can be used in in vitro or in vivo studies as exemplary
agents for comparative purposes to find other compounds also useful
in treatment of, or protection from, the various diseases disclosed
herein.
[0209] Another aspect of the invention relates to inhibiting
NaV1.1, NaV1.2, NaV1.3, NaV1.4, NaV1.5, NaV1.6, NaV1.7, NaV1.8, or
NaV1.9 activity, preferably NaV1.7 activity, in a biological sample
or a mammal, preferably a human, which method comprises
administering to the mammal, preferably a human, or contacting said
biological sample with a compound of formula (I) or a
pharmaceutical composition comprising a compound of formula (I).
The term "biological sample", as used herein, includes, without
limitation, cell cultures or extracts thereof; biopsied material
obtained from a mammal or extracts thereof; and blood, saliva,
urine, feces, semen, tears, or other body fluids or extracts
thereof.
[0210] Inhibition of NaV1.1, NaV1.2, NaV1.3, NaV1.4, NaV1.5,
NaV1.6, NaV1.7, NaV1.8, or NaV1.9 activity in a biological sample
is useful for a variety of purposes that are known to one of skill
in the art. Examples of such purposes include, but are not limited
to, the study of sodium ion channels in biological and pathological
phenomena; and the comparative evaluation of new sodium ion channel
inhibitors.
[0211] The compounds of the invention (or stereoisomers, geometric
isomers, tautomers, solvates, metabolites, isotopes,
pharmaceutically acceptable salts, or prodrugs thereof) and/or the
pharmaceutical compositions described herein which comprise a
pharmaceutically acceptable excipient and one or more compounds of
the invention, can be used in the preparation of a medicament for
the treatment of sodium channel-mediated disease or condition in a
mammal.
Combination Therapy
[0212] The compounds of the invention may be usefully combined with
one or more other compounds of the invention or one or more other
therapeutic agent or as any combination thereof, in the treatment
of sodium channel-mediated diseases and conditions. For example, a
compound of the invention may be administered simultaneously,
sequentially or separately in combination with other therapeutic
agents, including, but not limited to:
[0213] opiates analgesics, e.g., morphine, heroin, cocaine,
oxymorphine, levorphanol, levallorphan, oxycodone, codeine,
dihydrocodeine, propoxyphene, nalmefene, fentanyl, hydrocodone,
hydromorphone, meripidine, methadone, nalorphine, naloxone,
naltrexone, buprenorphine, butorphanol, nalbuphine and
pentazocine;
[0214] non-opiate analgesics, e.g., acetomeniphen, salicylates
(e.g., aspirin);
[0215] nonsteroidal antiinflammatory drugs (NSAIDs), e.g.,
ibuprofen, naproxen, fenoprofen, ketoprofen, celecoxib, diclofenac,
diflusinal, etodolac, fenbufen, fenoprofen, flufenisal,
flurbiprofen, ibuprofen, indomethacin, ketoprofen, ketorolac,
meclofenamic acid, mefenamic acid, meloxicam, nabumetone, naproxen,
nimesulide, nitroflurbiprofen, olsalazine, oxaprozin,
phenylbutazone, piroxicam, sulfasalazine, sulindac, tolmetin and
zomepirac;
[0216] anticonvulsants, e.g., carbamazepine, oxcarbazepine,
lamotrigine, valproate, topiramate, gabapentin and pregabalin;
[0217] antidepressants such as tricyclic antidepressants, e.g.,
amitriptyline, clomipramine, despramine, imipramine and
nortriptyline;
[0218] COX-2 selective inhibitors, e.g., celecoxib, rofecoxib,
parecoxib, valdecoxib, deracoxib, etoricoxib, and lumiracoxib;
[0219] alpha-adrenergics, e.g., doxazosin, tamsulosin, clonidine,
guanfacine, dexmetatomidine, modafinil, and
4-amino-6,7-dimethoxy-2-(5-methane
sulfonamido-1,2,3,4-tetrahydroisoquinol-2-yl)-5-(2-pyridyl)
quinazoline;
[0220] barbiturate sedatives, e.g., amobarbital, aprobarbital,
butabarbital, butabital, mephobarbital, metharbital, methohexital,
pentobarbital, phenobartital, secobarbital, talbutal, theamylal and
thiopental;
[0221] tachykinin (NK) antagonist, particularly an NK-3, NK-2 or
NK-1 antagonist, e.g., (.alpha.R,
9R)-7-[3,5-bis(trifluoromethyl)benzyl)]-8,9,10,11-tetrahydro-9-methyl-5-(-
4-methylphenyl)-7H-[1,4]diazocino[2,1-g][1,7]-naphthyridine-6-13-dione
(TAK-637),
5-[[2R,3S)-2-[(1R)-1-[3,5-bis(trifluoromethylphenyl]ethoxy-3-(4-fluorophe-
nyl)-4-morpholinyl]-methyl]-1,2-dihydro-3H-1,2,4-triazol-3-one
(MK-869), aprepitant, lanepitant, dapitant or
3-[[2-methoxy5-(trifluoromethoxy)phenyl]-methylamino]-2-phenylpiperidine
(2S,3S);
[0222] coal-tar analgesics, in particular paracetamol;
[0223] serotonin reuptake inhibitors, e.g., paroxetine, sertraline,
norfluoxetine (fluoxetine desmethyl metabolite), metabolite
demethylsertraline, '3 fluvoxamine, paroxetine, citalopram,
citalopram metabolite desmethylcitalopram, escitalopram,
d,l-fenfluramine, femoxetine, ifoxetine, cyanodothiepin,
litoxetine, dapoxetine, nefazodone, cericlamine, trazodone and
fluoxetine;
[0224] noradrenaline (norepinephrine) reuptake inhibitors, e.g.,
maprotiline, lofepramine, mirtazepine, oxaprotiline, fezolamine,
tomoxetine, mianserin, buproprion, buproprion metabolite
hydroxybuproprion, nomifensine and viloxazine (Vivalan.RTM.)),
especially a selective noradrenaline reuptake inhibitor such as
reboxetine, in particular (S,S)-reboxetine, and venlafaxine
duloxetine neuroleptics sedative/anxiolytics;
[0225] dual serotonin-noradrenaline reuptake inhibitors, such as
venlafaxine, venlafaxine metabolite O-desmethylvenlafaxine,
clomipramine, clomipramine metabolite desmethylclomipramine,
duloxetine, milnacipran and imipramine;
[0226] acetylcholinesterase inhibitors such as donepezil;
[0227] 5-HT3 antagonists such as ondansetron;
[0228] metabotropic glutamate receptor (mGluR) antagonists;
[0229] local anaesthetic such as mexiletine and lidocaine;
[0230] corticosteroid such as dexamethasone;
[0231] antiarrhythimics, e.g., mexiletine and phenytoin;
[0232] muscarinic antagonists, e.g., tolterodine, propiverine,
tropsium t chloride, darifenacin, solifenacin, temiverine and
ipratropium;
[0233] cannabinoids;
[0234] vanilloid receptor agonists (e.g., resinferatoxin) or
antagonists (e.g., capsazepine);
[0235] sedatives, e.g., glutethimide, meprobamate, methaqualone,
and dichloralphenazone;
[0236] anxiolytics such as benzodiazepines,
[0237] antidepressants such as mirtazapine,
[0238] topical agents (e.g., lidocaine, capsacin and
resiniferotoxin);
[0239] muscle relaxants such as benzodiazepines, baclofen,
carisoprodol, chlorzoxazone, cyclobenzaprine, methocarbamol and
orphrenadine;
[0240] anti-histamines or H1 antagonists;
[0241] NMDA receptor antagonists;
[0242] 5-HT receptor agonists/antagonists;
[0243] PDEV inhibitors;
[0244] Tramadol.RTM.;
[0245] cholinergic (nicotinc) analgesics;
[0246] alpha-2-delta ligands;
[0247] prostaglandin E2 subtype antagonists;
[0248] leukotriene B4 antagonists;
[0249] 5-lipoxygenase inhibitors; and
[0250] 5-HT3 antagonists.
[0251] Sodium channel-mediated diseases and conditions that may be
treated and/or prevented using such combinations include but not
limited to, pain, central and peripherally mediated, acute,
chronic, neuropathic as well as other diseases with associated pain
and other central nervous disorders such as epilepsy, anxiety,
depression and bipolar disease; or cardiovascular disorders such as
arrhythmias, atrial fibrillation and ventricular fibrillation;
neuromuscular disorders such as restless leg syndrome and muscle
paralysis or tetanus; neuroprotection against stroke, neural trauma
and multiple sclerosis; and channelopathies such as erythromyalgia
and familial rectal pain syndrome.
[0252] As used herein "combination" refers to any mixture or
permutation of one or more compounds of the invention and one or
more other compounds of the invention or one or more additional
therapeutic agent. Unless the context makes clear otherwise,
"combination" may include simultaneous or sequentially delivery of
a compound of the invention with one or more therapeutic agents.
Unless the context makes clear otherwise, "combination" may include
dosage forms of a compound of the invention with another
therapeutic agent. Unless the context makes clear otherwise,
"combination" may include routes of administration of a compound of
the invention with another therapeutic agent. Unless the context
makes clear otherwise, "combination" may include formulations of a
compound of the invention with another therapeutic agent. Dosage
forms, routes of administration and pharmaceutical compositions
include, but are not limited to, those described herein.
[0253] The invention will be more fully understood by reference to
the following examples. They should not, however, be construed as
limiting the scope of the invention.
[0254] These examples serve to provide guidance to a skilled
artisan to prepare and use the compounds, compositions and methods
of the invention. While particular embodiment of the present
invention are described, the skilled artisan will appreciate that
various changes and modifications can be made without departing
from the spirit and scope of the inventions.
[0255] The chemical reactions in the examples described can be
readily adapted to prepare a number of other compounds of the
invention, and alternative methods for preparing the compounds of
this invention are deemed to be within the scope of this invention.
For example, the synthesis of non-exemplified compounds according
to the invention can be successfully performed by modifications
apparent to those skilled in the art, for example, by appropriately
protecting interfering group, by utilizing other suitable reagents
known in the art, for example, by appropriately protecting
interfering groups by utilizing other suitable reagents known in
the art other than those described, and/or by making routine
modifications of reaction conditions.
[0256] In the examples below, unless otherwise indicated all
temperatures are set forth in degrees Celsius. Commercially
available reagents were purchased from suppliers such as Aldrich
Chemical Company, Lancaster, TCI or Maybridge and were used without
further purification unless otherwise indicated. The reactions set
forth below were done generally under a positive pressure of
nitrogen or argon or with a drying tube (unless otherwise stated)
in anhydrous solvents, and the reaction flasks were typically
fitted with rubber septa for the introduction of substrates and
reagents via syringe. Glassware was oven dried and/or heat dried.
.sup.1H NMR spectra were obtained in deuterated CDCl.sub.3,
d.sub.6-DMSO, CH.sub.3OD or d.sub.6-acetone solvent solutions
(reported in ppm) using or trimethylsilane (TMS) or residual
non-deuterated solvent peaks as the reference standard. When peak
multiplicities are reported, the following abbreviates are used: s
(singlet), d (doublet), t (triplet), q (quartet), m (multiplet, br
(broadened), dd (doublet of doublets), dt (doublet of triplets).
Coupling constants, when given, ar reported in Hz (Hertz).
[0257] All abbreviations used to describe reagents, reaction
conditions or equipment are intended to be consistent with the
definitions set forth in the following list of Abbreviations. The
chemical names of discrete compounds of the invention were
typically obtained using the structure naming feature of ChemDraw
naming program.
Abbreviations
[0258] DMF N,N-Dimethylformamide [0259] DMSO Dimethyl sulfoxide
[0260] HPLC High Pressure Liquid Chromatography [0261] LCMS Liquid
Chromatography Mass Spectrometry [0262] RT Retention time
EXAMPLES
Examples 1 and 2 Synthesis of
(1R,2R)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclop-
entane-1-carboxylic acid and
(1S,2S)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclop-
entane-1-carboxylic acid
##STR00032##
[0263] Step 1. Preparation of
4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl
chloride
##STR00033##
[0265] To a cooled (0.degree. C.) suspension of
4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoic acid
(Prepared as described in International Patent Application
Publication Number WO2013177224; 0.75 g, 2.18 mmol) in
dichloromethane (12 mL) was added oxalyl chloride (0.95 mL, 10.9
mmol) followed by dimethyl formamide (2 drops, catalytic). The
suspension was warmed to ambient temperature and stirred for 5
hours, resulting in a pale yellow solution. The reaction solvent
was concentrated in vacuo and the resulting solid (0.59 g, 74%
yield) was used in step 2 without further purification.
Step 2. Preparation of ethyl 2-iodocyclopentane-1-carboxylate
##STR00034##
[0267] To a stirred solution of polymer bound triphenylphosphine
(3.0 mmol/g, 1.45 g, 4.3 mmol), iodine (1.27 g, 5.0 mmol), and
imidazole (0.34 g, 5.0 mmol) in dichloromethane (20 mL) was added a
solution of ethyl 2-hydroxycyclopentane-1-carboxylate (1.15 g, 7.3
mmol) in dichloromethane (13 mL). The reaction mixture was stirred
at 30.degree. C. for 65 hours, diluted with dichloromethane (50
mL), filtered through celite and concentrated in vacuo. The residue
was purified by flash chromatography eluting with ethyl acetate in
hexanes to afford the title compound as a colorless liquid (0.62 g,
69% yield): .sup.1H NMR (300 MHz, CDCl.sub.3) .delta. 4.38-4.31 (m,
1H), 4.22-4.12 (m, 2H), 3.13-3.06 (m, 1H), 2.60-2.46 (m, 1H),
2.36-2.25 (m, 1H), 2.14-2.02 (m, 2H), 1.86-1.71 (m, 2H), 1.31-1.25
(m, 3H).
Step 3. Preparation of ethyl
(1,2-trans)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cy-
clopentane-1-carboxylate
##STR00035##
[0269] A 25 mL round bottom flask was charged with ethyl
2-iodocyclopentane-1-carboxylate (0.13 g, 0.48 mmol),
4,7-diphenyl-1,10-phenanthroline (0.024 g, 0.072 mmol), anhydrous
magnesium chloride (0.069 g, 0.72 mmol), nickel(II) acetylacetonate
(0.013 g, 0.048 mmol) and acid-washed zinc dust (0.095 g, 1.45
mmol). The flask was evacuated and flushed with argon gas twice to
remove oxygen. A suspension of
4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl chloride
(0.35 g, 0.97 mmol) in degassed acetonitrile (3 mL) was added
dropwise via syringe. The resulting red-brown suspension was
stirred for 16 hours under an argon atmosphere. The reaction
mixture was diluted with acetonitrile and filtered to remove the
solids. The filtrate was concentrated and the residue was diluted
with ethyl acetate (30 mL) and water (15 mL). The aqueous layer was
isolated and extracted with ethyl acetate (3.times.25 mL). The
combined organic layers were washed with brine; dried over
anhydrous magnesium sulfate, filtered and concentrated in vacuo.
The residue was purified by flash chromatography eluting with ethyl
acetate in hexanes to afford the title compound as a colorless
solid (0.099 g, 44% yield): .sup.1H NMR (300 MHz, CDCl.sub.3)
.delta. 7.44 (d, J=8.5 Hz, 1H), 6.50 (d, J=13.4 Hz, 1H), 4.08 (q,
J=7.1 Hz, 2H), 3.97-3.90 (m, 1H), 3.54 (s, 2H), 3.46-3.38 (m, 1H),
2.28-1.98 (m, 6H), 1.97-1.54 (m, 16H), 1.19 (t, J=7.1 Hz, 3H),
0.93-0.87 (m, 2H), 0.67-0.62 (m, 2H); MS (ES+) m/z 491.3 (M+1).
Step 4. Synthesis of
(1,2-trans)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cy-
clopentane-1-carboxylic acid
##STR00036##
[0271] To a solution of ethyl
(1R,2R)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclop-
entane-1-carboxylate (0.099 g, 0.21 mmol) in tetrahydrofuran (4 mL)
was added aqueous solution of lithium hydroxide (0.2 M, 0.63 mmol,
3.14 mL). The reaction mixture was stirred at ambient temperature
for 16 h. The reaction was partially concentrated and diluted with
diethyl ether (50 mL). The layers were separated and the aqueous
layer was extracted with diethyl ether (2.times.20 mL). The aqueous
layer was acidified with 1M aqueous hydrochloric acid, and
extracted with ethyl acetate (3.times.25 mL). The combined organic
layers were washed with brine, dried over anhydrous magnesium
sulfate, filtered and concentrated in vacuo. The residue was
purified by reverse-phase LC to afford racemic
(1,2-trans)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cy-
clopentane-1-carboxylic acid (0.033 g, 36%). The racemic material
was purified by SFC to afford the pure enantiomer
((1R,2R)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclo-
pentane-1-carboxylic acid and
(1S,2S)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclop-
entane-1-carboxylic acid)) as a colorless solid: .sup.1H NMR (300
MHz, CDCl.sub.3) .delta. 7.45 (d, J=8.5 Hz, 1H), 6.50 (d, J=13.5
Hz, 1H), 3.98-3.87 (m, 1H), 3.57-3.46 (m, 1H), 3.54 (s, 2H),
2.29-1.87 (m, 8H), 1.86-1.61 (m, 14H), 0.97-0.86 (m, 2H), 0.71-0.61
(m, 2H); MS (ES+) m/z 442.2, 441.2 (M+1), (ES-) m/z 440.2, 439.2
(M-1).
Examples 3 and 4 Synthesis of
(1,2-cis)-2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)cyclopent-
ane-1-carboxylic acid and
(1,2-trans)-2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)cyclope-
ntane-1-carboxylic
##STR00037##
[0273] To a cooled (-78.degree. C.) solution of
1-((4-bromo-2-chloro-5-fluorophenoxy)methyl) adamantane (1.50 g,
4.01 mmol) in tetrahydrofuran (9 mL) was added a solution of
butyllithium (1.6 M, 4.42 mmol, 2.8 mL). The solution was stirred
at -78.degree. C. for 0.5 h before a pre-cooled (-78.degree. C.)
solution of tetrahydro-1H-cyclopent[c]furan-1,3(3 aH)-dione (0.68
g, 4.81 mmol) in tetrahydrofuran (12 mL) was added dropwise via
cannula. The reaction was warmed to ambient temperature and stirred
for 16 h. The reaction was re-cooled (-78.degree. C.) then quenched
with saturated aqueous ammonium chloride (10 mL) and warmed to
ambient temperature. The aqueous layer was isolated and extracted
with ethyl acetate (3.times.50 mL). The combined organics were
dried over anhydrous sodium sulfate, decanted and concentrated in
vacuo. The resulting residue was purified by flash chromatography
eluting with ethyl acetate in hexanes to afford
2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)cyclopentane-1-carb-
oxylic acid (cis/trans mixture) contaminated with
tetrahydro-1H-cyclopent[c]furan-1,3(3aH)-dione (0.55 g). A portion
of crude material (0.20 g) was further purified by reverse-phase LC
to afford
(1,2-cis)-2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)cy-
clopentane-1-carboxylic acid (0.011 g); .sup.1H NMR (300 MHz,
CDCl.sub.3) .delta. 7.88 (d, J=7.6 Hz, 1H), 6.60 (d, J=12.7 Hz,
1H), 4.03-3.89 (m, 1H), 3.57 (s, 2H), 3.11-2.98 (m, 1H), 2.24-1.88
(m, 7H), 1.85-1.61 (m, 14H); MS (ES+) m/z 417.1, 435.1, 437.1,
(ES-) m/z 413.2, 433.2, 435.2.
(1,2-trans)-2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)cyclope-
ntane-1-carboxylic acid was also obtained as a colorless solid
(0.014 g): .sup.1H NMR (300 MHz, CDCl.sub.3) .delta. 7.92 (d, J=7.7
Hz, 1H), 6.62 (d, J=12.8 Hz, 1H), 4.00-3.87 (m, 1H), 3.57 (s, 2H),
3.57-3.47 (m, 1H), 2.29-1.87 (m, 7H), 1.87-1.60 (m, 14H); MS (ES+)
m/z 417.1, 435.1, 437.1, (ES-) m/z 413.2, 433.2, 435.2.
Example 5 Synthesis of
(1,2-trans)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzyl)cyc-
lopentane-1-carboxylic acid
##STR00038##
[0274] Step 1. Preparation of methyl
2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)-cyclopentane-1-car-
boxylate (cis/trans mixture)
##STR00039##
[0276] To a solution of crude
2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)-cyclopentane-1-car-
boxylic acid (cis/trans mixture) (0.35 g) in toluene (4 mL) and
methanol (1 mL) was added a solution of trimethylsilyldiazomethane
in hexanes (2.0 M, 1.0 mL, 2.01 mmol). The reaction solution was
stirred for 20 minutes then trimethylsilyldiazomethane solution
(0.5 mL, 1.0 mmol) was added. The reaction was stirred for an
additional 0.5 h, then cooled and quenched with glacial acetic acid
(0.5 mL).s. The filtrate was concentrated and the residue was
purified by column chromatography eluting with ethyl acetate in
hexanes to afford methyl
(1R,2S)-2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)cyclopentan-
e-1-carboxylate (cis/trans mixture) (0.095 g, 26% yield): 1,2-cis:
.sup.1H NMR (300 MHz, CDCl.sub.3) .delta. 7.87 (d, J=7.7 Hz, 1H),
6.61 (d, J=12.7 Hz, 1H), 3.98-3.87 (m, 1H), 3.64 (s, 3H), 3.56 (s,
2H), 3.11-3.01 (m, 1H), 2.19-1.61 (m, 21H); Also obtained
1,2-trans: .sup.1H NMR (300 MHz, CDCl.sub.3) .delta. 7.92 (d, J=7.7
Hz, 1H), 6.62 (d, J=12.7 Hz, 1H), 3.92 (dd, J=7.5, 15.1 Hz, 1H),
3.65 (s, 3H), 3.57 (s, 2H), 3.47 (dd, J=8.7, 15.3 Hz, 1H),
2.28-1.97 (m, 6H), 1.95-1.61 (m, 15H); MS (ES+) m/z 491.3
(M+1).
Step 2. Synthesis of methyl
(trans)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclop-
entane-1-carboxylate
##STR00040##
[0278] A mixture of methyl
(1R,2S)-2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)-cyclopenta-
ne-1-carboxylate (cis/trans mixture) (0.095 g, 0.212 mmol),
cyclopropylboronic acid (27.3 mg, 0.318 mmol) and potassium
phosphate (0.202 g, 0.954 mmol) in toluene (4 mL) and water (0.4
mL) was sparged with argon gas for 15 min before
tricyclohexylphosphine tetrafluoroborate (16 mg, 0.092 mmol) and
palladium acetate (5 mg, 0.021 mmol) were added. The reaction
mixture was heated to 110.degree. C. for 18 h and then cooled to
ambient temperature. The solids were removed by filtration and
rinsed with water (25 mL) and ethyl acetate (50 mL). The aqueous
layer was isolated and extracted with ethyl acetate (3.times.25
mL). The combined organic layers were washed with brine; dried over
anhydrous sodium sulfate, filtered and concentrated in vacuo. The
residue was purified by column chromatography eluting with ethyl
acetate in hexanes to afford the title compound (0.074 g, 77%
yield): .sup.1H NMR (300 MHz, CDCl.sub.3) .delta. 7.45 (d, J=8.5
Hz, 1H), 6.50 (d, J=13.5 Hz, 1H), 3.94 (dd, J=7.0, 14.7 Hz, 1H),
3.64 (s, 3H), 3.54 (s, 2H), 3.47 (dd, J=7.1, 15.3 Hz, 1H),
2.25-1.98 (m, 6H), 1.93-1.61 (m, 16H), 0.94-0.88 (m, 2H), 0.68-0.61
(m, 2H); MS (ES+) m/z 491.3 (M+1).
Step 3. Synthesis of methyl
(1,2-trans)-2-((R/S)-(4-(((3r,5r,7r)-adamantan-1-yl)methoxy)-5-cyclopropy-
l-2-fluorophenyl)(hydroxy)methyl)cyclopentane-1-carboxylate
##STR00041##
[0280] To a cooled (0.degree. C.) suspension of methyl
(1,2-trans)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cy-
clopentane-1-carboxylate (0.074 g, 0.163 mmol) in anhydrous
methanol (3 mL) was added sodium borohydride (0.005 g, 0.132 mmol).
The reaction mixture was warmed to ambient temperature and stirred
for 16 h. The reaction was concentrated and diluted with diethyl
ether (50 mL) and water (20 mL). The layers were separated and the
aqueous layer was extracted with diethyl ether (3.times.30 mL). The
combined organic layers were washed with brine, dried over
anhydrous magnesium sulfate, filtered, and concentrated in vacuo.
The residue was purified by flash chromatography eluting with ethyl
acetate in hexanes to afford the title compound (0.07 g, 94%
yield). The crude residue was subjected into step 4 without any
further characterization.
Step 4. Synthesis of methyl
(1,2-trans)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzyl)cyc-
lopentane-1-carboxylate
##STR00042##
[0282] To a cooled (0.degree. C.) solution of methyl
(1,2-trans)-2-((R/S)-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorophe-
nyl)(hydroxy)methyl)cyclopentane-1-carboxylate (0.070 g, 0.15 mmol)
in dichloromethane (1.5 mL) was added triethylsilane (0.050 mL,
0.31 mmol) followed by boron trifluoride diethyl etherate (0.040
mL, 0.31 mmol). The yellow solution was slowly warmed (over 1 h) to
ambient temperature and stirred for an additional 3 h. The reaction
was cooled (0.degree. C.) and carefully quenched with saturated
aqueous sodium bicarbonate solution (10 mL). The layers were
separated and the aqueous layer was extracted with dichloromethane
(3.times.50 mL). The combined organic layers were washed with
brine, dried over anhydrous sodium sulfate, filtered, and
concentrated in vacuo. The residue was purified by flash
chromatography with a gradient 0% to 50% dichloromethane in hexanes
to afford the title compound (0.063 g, 93%). The crude residue was
subjected into step 5 without any further characterization.
Step 5. Synthesis of
(1,2-trans)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzyl)cyc-
lopentane-1-carboxylic acid
##STR00043##
[0284] Following the procedure as described in Example 1 (Step 4)
and making non-critical variations as required to replace ethyl
(1R,2R)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclop-
entane-1-carboxylate with methyl
(1,2-trans)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzyl)cyc-
lopentane-1-carboxylate, the title compound was obtained following
purification by reverse-phase as a colorless solid (0.0145 g, 24%
yield): .sup.1H NMR (300 MHz, CDCl.sub.3) .delta. 6.64 (d, J=8.6
Hz, 1H), 6.48 (d, J=11.8 Hz, 1H), 3.45 (s, 2H), 2.76 (dd, J=4.2,
13.4 Hz, 1H), 2.59-2.35 (m, 3H), 2.11-1.83 (m, 6H), 1.83-1.58 (m,
15H), 1.37-1.21 (m, 1H), 0.96-0.81 (m, 2H), 0.66-0.53 (m, 2H); MS
(ES+) m/z 427.2, 428.2, (ES-) m/z 425.3, 426.3.
Example 6 Synthesis of
trans-2-(4-((-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclo-
hexane-1-carboxylic acid
##STR00044##
[0285] Step 1. Preparation of
2-(4-(adamantan-1-ylmethoxy)-5-chloro-2-fluorobenzoyl)-cyclohexanecarboxy-
lic acid
##STR00045##
[0287] To a cooled (0.degree. C.) stirred solution of
1-((4-bromo-2-chloro-5-fluorophenoxy)methyl)adamantane (0.5 g, 1.34
mmol) in tetrahydrofuran (8 mL) was added a solution of
isopropylmagnesium chloride lithium chloride complex in
tetrahydrofuran (1.3 M, 2.2 mL, 2.81 mmol) dropwise. The reaction
mixture was stirred at 0.degree. C. for 1 h, and further solution
of isopropylmagnesium chloride lithium chloride complex in
tetrahydrofuran (1.3 M, 0.52 mL, 0.67 mmol) was added dropwise. The
reaction mixture was stirred at 0.degree. C. for 1 h,
cis-1,2-cyclohexanedicarboxylic anhydride (0.31 g, 2.00 mmol) was
added in one portion and stirring was continued at 0.degree. C. for
another 1 h. An aqueous solution of saturated ammonium chloride (20
mL) was added and the mixture was extracted with ethyl acetate
(3.times.30 mL). The combined organic layers were washed with brine
(30 mL), dried over anhydrous magnesium sulfate, filtered and
concentrated in vacuo. The residue was triturated with hexanes to
afford the title compound as a colorless solid (0.28 g, 70% yield):
.sup.1H NMR (300 MHz, CDCl.sub.3) .delta.7.87-7.76 (m, 1H),
6.66-6.55 (m, 1H), 3.72-3.62 (m, 1H), 3.56 (s, 2H), 2.79-2.69 (m,
1H), 2.19-1.91 (m, 5H), 1.87-1.64 (m, 14H), 1.51-1.26 (m, 4H); MS
(ES+) m/z 949.2, 951.2 (M+1).
Step 2. Preparation of methyl
2-(4-((adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)cyclohexane-1-car-
boxylate
##STR00046##
[0289] To a cooled (0.degree. C.) stirred solution of
2-(4-adamantan-1-ylmethoxy)-5-chloro-2-fluorobenzoyl)cyclohexanecarboxyli-
c acid (0.27 g, 0.6 mmol) was added a solution of
(trimethylsilyl)diazomethane in hexanes (0.3 mL, 2M solution in
hexanes, 1.2 mmol) dropwise. The reaction mixture was stirred at
ambient temperature for 2 h and concentrated in vacuo. The residue
was purified by column chromatography eluting with ethyl acetate in
hexanes to afford the title compound as colorless oil (0.18 g, 65%
yield): MS (ES+) m/z 465.2, 463.2 (M+1).
Step 3. Preparation of methyl
2-(4-((adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclohexane--
1-carboxylate
##STR00047##
[0291] Following the procedure as described in Example 5 (Step 2)
and making non-critical variations as required to replace methyl
(1R,2S)-2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)cyclopentan-
e-1-carboxylate (cis/trans mixture) with methyl
2-(4-((adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)cyclohexane-1-car-
boxylate, the title compound was obtained as a colorless solid
(0.14 g, 77% yield) which was used in step 4 without any further
characterization: MS (ES+) m/z 491.3 (M+1);
Step 4. Synthesis of
trans-2-(4-((-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclo-
hexane-1-carboxylic acid
##STR00048##
[0293] Following the procedure as described in Example 1 (Step 4)
and making non-critical variations as required to replace ethyl
(1R,2R)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclop-
entane-1-carboxylate with methyl
2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclohexane-1--
carboxylate, title compound was obtained following re-crystallized
from methanol to afford the title compound as a colorless solid
(0.057 g, 45%): .sup.1H NMR (300 MHz, CDCl.sub.3) .delta.7.48-7.42
(m, 1H), 6.53-6.44 (m, 1H), 3.54 (s, 2H), 3.45-3.33 (m, 1H),
2.92-2.78 (m, 1H), 2.23-1.95 (m, 6H), 1.90-1.61 (m, 14H), 1.54-1.24
(m, 3H), 1.20-1.03 (m, 1H), 0.94-0.82 (m, 2H), 0.71-0.58 (m, 2H);
MS (ES+) m/z 455.1 (M+1).
Example 7 Synthesis of
trans-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclobut-
ane-1-carboxylic acid (racemic mixture
##STR00049##
[0294] Step 1. Preparation of
2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)cyclobutane-1-carbo-
xylic acid
##STR00050##
[0296] To a cooled (-78.degree. C.) stirred solution of
1-((4-bromo-2-chloro-5-fluorophenoxy)-methyl)adamantane (0.5 g,
1.34 mmol) in tetrahydrofuran (3 mL) was added a solution of
n-butyl lithium (0.9 mL, 1.6 M solution in tetrahydrofuran, 1.47
mmol) dropwise. The reaction mixture was stirred at -78.degree. C.
for 0.5 h and was added via a cannula to a cooled (-78.degree. C.)
stirred solution of 3-oxabicyclo[3.2.0]heptane-2,4-dione (0.2 g,
1.61 mmol) in tetrahydrofuran (4 mL). Stirring was continued at
-78.degree. C. for 4 h. An aqueous solution of saturated ammonium
chloride (20 mL) and water (20 mL) were added, and the mixture was
extracted with ethyl acetate (3.times.30 mL). The combined organic
layers were washed with water (30 mL) and brine (30 mL), dried over
anhydrous sodium sulfate, filtered and concentrated in vacuo. The
residue was purified by column chromatography using gradient 0% to
20% ethyl acetate with 0.2% formic acid in hexanes to afford the
title compound as yellow solid (0.085 g, 23% yield): MS (ES+) m/z
420.8, 418.8 (M-1).
Step 2. Preparation of methyl
2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)cyclobutane-1-carbo-
xylate
##STR00051##
[0298] To a stirred solution of
2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)-cyclobutane-1-carb-
oxylic acid (0.062 g, 0.15 mmol) was added a solution of
(trimethylsilyl)-diazomethane in hexanes (2.0 M, 0.29 mmol, 0.2 mL)
dropwise. The reaction mixture was stirred at ambient temperature
for 4 h, (trimethylsilyl)diazomethane in hexanes (2.0 M, 0.15 mmol,
0.1 mL) was added dropwise, and stirring was continued at ambient
temperature for 0.5 h. The solvent was concentrated in vacuo to
afford the title compound as a yellow solid (0.059 g, 92% yield):
MS (ES+) m/z 437.0, 435.1 (M+1).
Step 3. Preparation of methyl
2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclobutane-1--
carboxylate
##STR00052##
[0300] A mixture of methyl
2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)-cyclobutane-1-carb-
oxylate (0.08 g, 0.18 mmol), cyclopropylboronic acid (0.05 g, 0.55
mmol) and potassium phosphate (0.18 g, 0.83 mmol) in toluene (2.3
mL) and water (0.1 mL) was purged with argon for 10 min, and
tricyclohexylphosphine tetrafluoroborate (0.014 g, 0.04 mmol) and
palladium acetate (0.004 g, 0.02 mmol) were added. The reaction
mixture was heated to 130.degree. C. for 0.5 h in the microwave and
then cooled to ambient temperature. Hydrochloric acid (1 M, 20 mL)
was added and the mixture was extracted with ethyl acetate
(3.times.40 mL). The combined organic layers were washed with
brine; dried over anhydrous sodium sulfate, filtered and
concentrated in vacuo. The residue was purified by column
chromatography eluting with ethyl acetate in hexanes to afford the
title compound as a yellow oil (0.08 g, 43% yield): .sup.1H NMR
(300 MHz, CDCl.sub.3) .delta. 7.47 (d, J=8.4 Hz, 1H), 6.48 (d,
J=13.3 Hz, 1H), 3.68 (s, 3H), 3.54 (s, 2H), 2.42-2.00 (m, 7H),
1.80-1.62 (m, 15H), 0.94-0.88 (m, 2H), 0.68-0.61 (m, 2H).
Step 4. Synthesis of
trans-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclobut-
ane-1-carboxylic acid
##STR00053##
[0302] Following the procedure as described in Example 1 (Step 4)
and making non-critical variations as required to replace ethyl
(1R,2R)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclop-
entane-1-carboxylate with methyl
2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclobutane-1--
carboxylate, title compound was obtained following purification by
column chromatography using gradient 0% to 20% ethyl acetate with
0.2% formic acid in hexanes as a colorless solid (0.019 g, 25%
yield): .sup.1H NMR (300 MHz, DMSO-d.sub.6) .delta. 12.29 (br s,
1H), 7.32 (d, J=8.4 Hz, 1H), 6.90 (d, J=13.5 Hz, 1H), 4.00 (q,
J=8.7 Hz, 1H), 3.66 (s, 2H), 3.41-3.24 (m, 2H), 2.31-1.91 (m, 6H),
1.75-1.57 (m, 13H), 0.93-0.90 (m, 2H), 0.64-0.62 (m, 2H); MS (ES+)
m/z 427.1 (M+1).
Example 8 Synthesis of
trans-2-(4-(benzyloxy)-5-cyclopropyl-2-fluorobenzoyl)-cyclopentane-1-carb-
oxylic acid
##STR00054##
[0303] Step 1. Preparation of diethyl trans
cyclopentane-1,2-dicarboxylate
##STR00055##
[0305] To a solution of trans cyclopentane-1,2-dicarboxylic acid
(5.00 g, 31.62 mmol) in absolute ethanol (100 mL) was added
concentrated sulfuric acid (3 mL). The reaction mixture was fitted
with a condenser and heated at reflux for 16 h, after which it was
evaporated dry in vacuo. The resulting residue was diluted with
saturated sodium bicarbonate (100 mL), and washed with
dichloromethane (3.times.100 mL). The combined organic extracts
were dried over anhydrous magnesium sulfate and concentrated in
vacuo to afford the title compound as light yellow oil (6.10 g, 90%
yield), which was used directly for the next step.
Step 2. Preparation of
trans-2-(ethoxycarbonyl)cyclopentane-1-carboxylic acid
##STR00056##
[0307] To a solution of diethyl
trans-cyclopentane-1,2-dicarboxylate (6.09 g, 28.46 mmol) in
ethanol (28.0 mL) was added a solution of potassium hydroxide (2.07
g, 37.00 mmol) in water and ethanol (20.2 mL, 1:5). The reaction
mixture was stirred at room temperature overnight, after which it
was diluted with hydrochloric acid (1 mol/L in water) and washed
with ethyl acetate (3.times.100 mL). The combined organic extracts
were dried over anhydrous magnesium sulfate, filtered, and
concentrated. The resulting syrup was purified by column
chromatography eluting with ethyl acetate to afford the title
compound as a pale yellow oil (2.76 g, 52% yield): .sup.1H NMR (300
MHz, CDCl.sub.3) .delta. 4.93 (q, J=6.9 Hz, 2H), 3.18-3.03 (m, 2H),
2.11-2.02 (m, 2H), 1.89-1.69 (m, 4H), 1.23 (t, J=7.2 Hz, 3H).
Step 3. Preparation of ethyl trans
2-(chlorocarbonyl)cyclopentane-1-carboxylate
##STR00057##
[0309] To a solution of trans
2-(ethoxycarbonyl)cyclopentane-1-carboxylic acid (2.76 g, 14.85
mmol) in anhydrous dichloromethane (30 mL) was slowly added thionyl
chloride (15 mL). The reaction mixture was stirred at room
temperature overnight, after which TLC analysis indicated complete
consumption of the starting material. The solvent was removed in
vacuo to afford the title compound which was used in step 4 without
further purification.
Step 4. Preparation of ethyl trans
2-(4-(benzyloxy)-5-chloro-2-fluorobenzoyl)-cyclopentane-1-carboxylate
##STR00058##
[0311] To a cooled (-50.degree. C.), stirred solution of
1-(benzyloxy)-4-bromo-2-chloro-5-fluorobenzene (2.35 g, 7.42 mmol)
in tetrahydrofuran (15.0 mL) was added a solution of
isopropylmagnesium chloride lithium chloride complex (1.3 mol/L in
THF, 1.5 equivalents) dropwise over 5 minutes. After 20 minutes,
the reaction mixture was cooled to -78.degree. C., and a solution
of ethyl trans 2-(chlorocarbonyl)cyclopentane-1-carboxylate (14.9
mmol) dissolved in tetrahydrofuran (20 mL) was added dropwise. The
reaction mixture was stirred at the same temperature for 3 h then
quenched with saturated ammonium chloride (75 mL), washed with
ethyl acetate (3.times.75 mL), and the combined organic extracts
were dried over anhydrous magnesium sulfate, filtered and
concentrated in vacuo. The residue was purified by column
chromatography eluting with ethyl acetate in hexanes to afford the
title compound as a clear oil (2.11 g, 70% yield): .sup.1H NMR (300
MHz, CDCl.sub.3) .delta. 7.92 (d, J=7.5 Hz, 1H), 7.47-7.25 (m, 5H),
6.69 (d, J=12.3 Hz, 1H), 5.15 (s, 2H), 4.07 (q, J=7.2 Hz, 2H),
3.92-3.85 (m, 1H), 3.40 (q, J=7.8 Hz, 1H), 2.16-2.02 (m, 2H),
1.93-1.57 (m, 4H), 1.67 (t, J=6.9 Hz, 3H); MS (ES+) m/z 407.2,
405.1 (M+1).
Step 5. Preparation of ethyl trans
2-(4-(benzyloxy)-5-cyclopropyl-2-fluorobenzoyl)cyclopentane-1-carboxylate
##STR00059##
[0313] Following the procedure as described in Example 5 (Step 2)
and making non-critical variations as required to replace methyl
2-(4-adamantan-1-yl)methoxy)-5-chloro-2-fluorobenzoyl)cyclopentane-1-carb-
oxylate (cis/trans mixture) with ethyl trans
2-(4-(benzyloxy)-5-chloro-2-fluorobenzoyl)cyclopentane-1-carboxylate,
the title compound was obtained as a yellow oil (0.15 g, 10%
yield): .sup.1H NMR (300 MHz, CDCl.sub.3) .delta. 7.51-7.20 (m,
6H), 6.67-6.50 (m, 1H), 5.20-5.05 (m, 2H), 4.17-4.05 (m, 2H),
3.97-3.80 (m, 1H), 3.50-3.32 (m, 1H), 2.25-1.95 (m, 3H), 1.95-1.55
(m, 4H), 1.27-1.05 (m, 3H), 0.91 (br s, 2H), 0.67 (br s, 2H), MS
(ES+) m/z 411.1 (M+1).
Step 6. Preparation of trans
2-(4-(benzyloxy)-5-cyclopropyl-2-fluorobenzoyl)cyclopentane-1-carboxylic
acid
##STR00060##
[0315] Following the procedure as described in Example 1 (Step 4)
and making non-critical variations as required to replace ethyl
2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclopentane-1-
-carboxylate with ethyl trans
2-(4-(benzyloxy)-5-cyclopropyl-2-fluorobenzoyl)cyclopentane-1-carboxylate-
, the title compound was obtained following lyophilization from
acetonitrile (0.5 mL) and water (5.0 mL) as a pale yellow solid:
.sup.1H NMR (300 MHz, DMSO-d.sub.6) .delta. 7.45-7.33 (m, 6H), 6.59
(d, J=12.4 Hz, 1H), 3.92 (q, J=6.9 Hz, 1H), 3.98 (q, J=7.8 Hz, 1H),
2.21-1.66 (m, 7H), 0.93-0.88 (m, 2H), 0.69-0.64 (m, 2H); MS (ES-)
m/z 381.1 (M-1).
Example 9 Synthesis of
(1,2-trans)-2-(5-cyclopropyl-4-((1-((S)-1-(3,5-dichlorophenyl)ethyl)piper-
idin-4-yl)methoxy)-2-fluorobenzoyl)cyclopentane-1-carboxylic
acid
##STR00061##
[0316] Step 1. Preparation of
(S)-5-cyclopropyl-4-((1-(1-(3,5-dichlorophenyl)ethyl)piperidin-4-yl)metho-
xy)-2-fluorobenzoyl chloride
##STR00062##
[0318] To a cooled (0.degree. C.) suspension
(S)-5-cyclopropyl-4-((1-(1-(3,5-dichlorophenyl)ethyl)-piperidin-4-yl)meth-
oxy)-2-fluorobenzoic acid (Prepared accordingly as described in
International Patent Application Publication Number WO2013177224)
(0.60 g, 1.29 mmol) in dichloromethane (15 mL) was added oxalyl
chloride (0.56 mL, 6.43 mmol) followed by dimethyl formamide (2
drops, catalytic). The suspension was warmed to ambient temperature
and stirred for 4 h, resulting in a pale yellow solution. The
reaction was concentrated and the resulting crude solid (0.65 g,
quantitative yield) was used without further purification.
Step 2. Synthesis of ethyl
(1,2-trans)-2-(5-cyclopropyl-4-((1-((S)-1-(3,5-dichlorophenyl)ethyl)-pipe-
ridin-4-yl)methoxy)-2-fluorobenzoyl)cyclopentane-1-carboxylate
##STR00063##
[0320] Following the procedure as described in Example 1 (Step 3)
and making non-critical variations as required to replace
4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl chloride
with
(S)-5-cyclopropyl-4-((1-(1-(3,5-dichlorophenyl)ethyl)piperidin-4-yl)metho-
xy)-2-fluorobenzoyl chloride, the title compound was obtained as a
colorless gum (0.20 g, 51% yield). The residue was used in step 3
without any further purification: MS (ES+) m/z 592.3, 590.3
(M+1).
Step 3. Synthesis of (1,2-trans)-2-(5-cyclopropyl-4-((1-((S)-1-(3,
5-dichlorophenyl)ethyl)-piperidin-4-yl)methoxy)-2-fluorobenzoyl)cyclopent-
ane-1-carboxylic acid
##STR00064##
[0322] To a solution of ethyl
(1,2-trans)-2-(5-cyclopropyl-4-((1-((S)-1-(3,5-dichlorophenyl)-ethyl)pipe-
ridin-4-yl)methoxy)-2-fluorobenzoyl)cyclopentane-1-carboxylate
(0.20 g, 0.34 mmol) in tetrahydrofuran (10 mL) was added aqueous
solution of lithium hydroxide (0.2 M, 1.02 mmol, 5.10 mL). The
reaction mixture was stirred at ambient temperature for 16 h. The
reaction was partially concentrated and diluted with ethyl acetate
(50 mL). The layers were separated and the aqueous layer was
acidified with 1M aqueous hydrochloric acid, and extracted with
ethyl acetate (3.times.25 mL). The combined organic layers were
washed with brine, dried over anhydrous magnesium sulfate, filtered
and concentrated in vacuo. The residue was purified by
reverse-phase LC to afford the title compound as a colorless solid
(0.14 g, 71% yield): .sup.1H NMR (300 MHz, DMSO-d.sub.6) .delta.
9.77 (s, 1H), 7.77 (s, 1H), 7.66 (d, J=1.7 Hz, 2H), 7.29 (d, J=8.5
Hz, 1H), 6.96 (d, J=13.6 Hz, 1H), 4.63-4.50 (m, 1H), 3.99 (d, J=5.5
Hz, 2H), 3.82 (dd, J=7.1, 14.8 Hz, 1H), 3.69 (d, J=11.8 Hz, 1H),
3.36 (d, J=10.2 Hz, 1H), 3.16 (dd, J=7.8, 15.6 Hz, 1H), 2.84 (s,
2H), 2.18-1.85 (m, 6H), 1.85-1.47 (m, 9H), 0.96-0.80 (m, 2H),
0.69-0.53 (m, 2H); MS (ES+) m/z 564.1, 562.1 (M+1); (ES-) m/z
562.1, 560.1 (M-1).
Example 10 Synthesis of
(1,2-trans)-2-(5-cyclopropyl-4-((3,5-dichlorophenoxy)methyl)-2-fluorobenz-
oyl)cyclopentane-1-carboxylic acid
##STR00065##
[0323] Step 1. Preparation of
5-cyclopropyl-4-((3,5-dichlorophenoxy)methyl)-2-fluorobenzoyl
chloride
##STR00066##
[0325] To a stirred suspension of
5-cyclopropyl-4-((3,5-dichlorophenoxy)methyl)-2-fluorobenzoic acid
(prepared accordingly as described in WO2014008458) (0.6 g, 1.72
mmol) in dichloromethane (9 mL) was added oxalyl chloride (0.95 mL,
10.9 mmol) followed by N,N-dimethylformamide (2 drops, catalytic).
The suspension was stirred for 3 h, resulting in a pale yellow
solution. The reaction was concentrated and the resulting solid
(0.66 g, 99%) was used without further purification: .sup.1H NMR
(300 MHz, CDCl.sub.3) .delta. 7.82 (d, J=7.0 Hz, 1H), 7.33 (d,
J=11.4 Hz, 1H), 7.04 (t, J=1.7 Hz, 1H), 6.90 (d, J=1.7 Hz, 2H),
5.25 (s, 2H), 1.91-1.81 (m, 1H), 1.10-1.04 (m, 2H), 0.78-0.73 (m,
2H).
Step 2. Preparation of ethyl
(1,2-trans)-2-(5-cyclopropyl-4-((3,5-dichlorophenoxy)methyl)-2-fluorobenz-
oyl)cyclopentane-1-carboxylate
##STR00067##
[0327] Following the procedure as described in Example 1 (Step 3)
and making non-critical variations as required to replace
4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl chloride
with 5-cyclopropyl-4-((3,5-dichlorophenoxy)methyl)-2-fluorobenzoyl
chloride, the title compound was obtained as a colorless gum (0.14
g, 54% yield): MS (ES+) m/z 481.0, 479.0 (M+1).
Step 3. Preparation of
(1,2-trans)-2-(5-cyclopropyl-4-((3,5-dichlorophenoxy)methyl)-2-fluorobenz-
oyl)cyclopentane-1-carboxylic acid
##STR00068##
[0329] To a solution of ethyl (1,2-trans)-2-(5-cyclopropyl-4-((3,
5-dichlorophenoxy)methyl)-2-fluorobenzoyl)cyclopentane-1-carboxylate
(0.14 g, 0.30 mmol) in tetrahydrofuran (6 mL) was added aqueous
solution of lithium hydroxide (0.2 M, 0.90 mmol, 4.5 mL). The
reaction mixture was stirred at ambient temperature for 16 h. The
reaction was partially concentrated, diluted with water (20 mL) and
acidified with 1M aqueous hydrochloric acid, and extracted with
ethyl acetate (3.times.35 mL). The combined organic layers were
washed with brine, dried over anhydrous sodium sulfate, filtered,
and concentrated in vacuo. The residue was crystallized from
methanol to afford the title compound as a colorless solid (0.076
g, 56% yield): .sup.1H NMR (300 MHz, DMSO-d.sub.6) .delta. 12.27
(s, 1H), 7.46-7.38 (m, 2H), 7.26 (d, J=1.8 Hz, 2H), 7.22 (t, J=1.7
Hz, 1H), 5.36 (s, 2H), 3.92-3.85 (m, 1H), 3.17-3.16 (m, 1H),
2.10-1.90 (m, 3H), 1.82-1.57 (m, 4H), 0.99-0.92 (m, 2H), 0.74-0.64
(m, 2H); MS (ES-) m/z 449.0, 451.0 (M-1).
Examples 11 and 12 Synthesis of
2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)-5-methylcyclo-
pentane-1-carboxylic acid
##STR00069##
[0330] Step 1. Preparation of ethyl
2-iodo-5-methylcyclopentane-1-carboxylate
##STR00070##
[0332] To a stirred solution of triphenylphosphine (1.89 g, 7.2
mmol), and ethyl 2-hydroxy-5-methylcyclopentane-1-carboxylate (0.62
g, 3.69 mmol) in anhydrous tetrahydrofuran (25 mL), iodine (0.74 g,
10.8 mmol) was added at 0.degree. C. The reaction mixture was
stirred at an ambient temperature for 16 h, diluted with ethyl
acetate (70 mL), and washed with saturated sodium thiosulfate (70
mL), saturated ammonium chloride (70 mL), brine (50 mL) and dried
over sodium sulfate. The solid was filtered and solvent was
concentrated in vacuo. The residue was purified by flash
chromatography with gradient 0% to 10% ethyl acetate in hexanes to
afford the title compound as a colorless liquid (0.72 g, 69% yield)
which was used directly in step 2 without any further
characterization: MS (ES+) m/z 283.1 (M+1).
Step 2. Preparation of ethyl
2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)-5-methylcyclo-
pentane-1-carboxylate
##STR00071##
[0334] Following the procedure as described in Example 1 (Step 3)
and making non-critical variations as required to replace ethyl
2-iodocyclopentane-1-carboxylate with ethyl
2-iodo-5-methylcyclopentane-1-carboxylate, the title compound was
obtained as a colorless gum (0.14 g, 54% yield) which was subjected
to next step without any further characterization: MS (ES+) m/z
483.4 (M+1).
Step 3. Preparation of
2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)-5-methylcyclo-
pentane-1-carboxylic acid
##STR00072##
[0336] Following the procedure as described in Example 1 (Step 4)
and making non-critical variations as required to replace ethyl
2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclopentane-1-
-carboxylate with ethyl
2-(4adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)-5-methylcyclop-
entane-1-carboxylate, the title compound was obtained as a
colorless solid (0.11 g, 46% yield): .sup.1H NMR (300 MHz,
CDCl.sub.3) .delta. 11.25 (br s, 1H), 7.43 (d, J=8.4 Hz, 1H), 6.47
(d, J=13.4 Hz, 1H), 4.01-3.89 (m, 1H), 3.52 (s, 2H), 3.04 (t,
J=9.06 Hz, 1H), 2.32-2.08 (m, 2H), 2.06-1.95 (m, 4H), 1.94-1.82 (m,
1H), 1.81-1.61 (m, 12H), 1.34-1.19 (m, 2H), 1.16 (d, J=6.5 Hz, 3H),
0.92-0.84 (m, 2H), 0.66-0.58 (m, 2H); MS (ES+) m/z 455.3 (M+1).
Example 13 Synthesis of
(1R,2R)-2-(4-((1-(2-chloro-5-(trifluoromethyl)benzyl)piperidin-4-yl)metho-
xy)-5-cyclopropyl-2-fluorobenzoyl)cyclopentane-1-carboxylic
acid
##STR00073##
[0337] Step 1. Preparation of ethyl
(1R,2R)-2-(5-cyclopropyl-2-fluoro-4-hydroxybenzoyl)-cyclopentane-1-carbox-
ylate
##STR00074##
[0339] To a solution of trans ethyl
2-(4-(benzyloxy)-5-cyclopropyl-2-fluorobenzoyl)-cyclopentane-1-carboxylat-
e (0.12 g, 0.29 mmol) in methanol (2.5 mL) was added palladium on
charcoal (0.10 g). The flask was brought under vacuum and
backfilled with an atmosphere of hydrogen gas and stirred at room
temperature for 1 hour. The reaction mixture was then filtered over
Celite and the filter pad was washed with ethyl acetate (75 mL).
The solvent was concentrated in vacuo to afford the title compound
as a yellow solid (0.092 g, 98% yields): .sup.1H NMR (300 MHz,
CDCl.sub.3) .delta. 7.61 (d, J=8.4 Hz, 1H), 6.58-6.54 (m, 2H), 4.08
(q, J=6.9 Hz, 2H), 3.95-3.88 (q, J=7.5 Hz, 1H), 3.41 (q, J=7.5 Hz,
1H), 2.19-2.03 (m, 2H), 1.88-1.62 (m, 5H), 1.176 (t, J=7.2 Hz, 3H),
0.98-0.92 (m, 2H), 0.65-0.60 (m, 2H); MS (ES-) m/z 319.0 (M-1).
Step 2. Preparation of tert-butyl
4-((2-cyclopropyl-4-((1R,2R)-2-(ethoxycarbonyl)-cyclopentane-1-carbonyl)--
5-fluorophenoxy)methyl)piperidine-1-carboxylate
##STR00075##
[0341] To a solution of ethyl
2-(5-cyclopropyl-2-fluoro-4-hydroxybenzoyl)cyclopentane-1-carboxylate
(0.092 g, 0.29 mmol) in N,N-dimethylformamide (2.9 mL) was added
cesium carbonate (0.14 g, 0.44 mmol) and tert-butyl
4-((tosyloxy)methyl)piperidine-1-carboxylate (0.16 g, 0.44 mmol).
The reaction mixture was stirred at 70.degree. C. for 4 h, cooled
to ambient temperature and diluted with saturated aqueous ammonium
chloride and extracted with ethyl acetate (3.times.75 mL). The
combined organic layers were washed with 5% aqueous lithium
chloride, dried over magnesium sulfate, filtered and concentrated
in vacuo. The residue was purified by flash chromatography with
ethyl acetate in hexanes to afford the title compound as a
colorless solid (0.12 g, 82% yield): .sup.1H NMR (300 MHz,
CDCl.sub.3) .delta. 7.39 (d, J=8.4 Hz, 1H), 6.48 (d, J=13.2 Hz,
1H), 4.18-4.03 (m, 6H), 3.91 (q, J=7.5 Hz, 1H), 3.84 (d, J=6.0 Hz,
2H), 3.39 (q, J=7.8 Hz, 1H), 2.78-2.69 (m, 2H), 2.78-2.69 (m, 2H),
2.15-1.95 (m, 4H), 1.87-1.61 (m, 6H), 1.44 (s, 9H), 1.16 (t, J=6.3
Hz, 3H), 0.92-0.82 (m, 2H), 0.64-0.58 (m, 2H); MS (ES+) m/z 518.3
(M+1).
Step 3. Preparation of ethyl
2-(4-((1-(2-chloro-5-(trifluoromethyl)benzyl)piperidin-4-yl)methoxy)-5-cy-
clopropyl-2-fluorobenzoyl)cyclopentane-1-carboxylate
##STR00076##
[0343] To a solution of tert-butyl
4-((2-cyclopropyl-4-2-(ethoxycarbonyl)cyclopentane-1-carbonyl)-5-fluoroph-
enoxy)methyl)piperidine-1-carboxylate (0.12 g, 0.24 mmol) in
anhydrous dichloromethane (2.4 mL) was added trifluoroacetic acid
(0.37 mL, 4.8 mmol). The reaction solution was stirred for 2 h then
concentrated in vacuo. The residue was redissolved in anhydrous
N,N-dimethylformamide (2.4 mL) then cesium carbonate (0.42 g, 1.3
mmol) and 2-chloro-5-(trifluoromethyl)benzyl
4-methylbenzenesulfonate (0.13 g, 0.45 mmol) were added. The
reaction mixture was heated at 80.degree. C. for 16 h. The reaction
mixture was cooled to ambient temperature and quenched with
saturated sodium bicarbonate (15 mL). The reaction mixture was
extracted with ethyl acetate (3.times.50 mL), dried over magnesium
sulfate, concentrated in vacuo. The residue was purified by column
chromatography eluting with ethyl acetate in hexanes to afford the
title compound as a colorless solid (0.035 g, 24% yield): .sup.1H
NMR (300 MHz, DMSO-d.sub.6) .delta. 7.79 (br s, 1H), 7.50-7.34 (m,
2H), 7.28-7.21 (m, 1H), 6.54-6.47 (m, 1H), 4.079 (m, 2H), 4.00-3.85
(m, 3H), 3.64 (br s, 2H), 3.49-3.39 (m, 1H), 2.92 (br s, 2H),
2.26-1.95 (m, 5H), 1.88-1.84 (m, 4H), 1.75-1.45 (m, 5H), 1.22-1.14
(m, 3H), 0.95-0.81 (m, 2H), 0.71-0.56 (m, 2H); MS (ES+) m/z 612.2,
610.3 (M+1).
Step 4. Preparation of
trans-2-(4-((1-(2-chloro-5-(trifluoromethyl)benzyl)-piperidin-4-yl)methox-
y)-5-cyclopropyl-2-fluorobenzoyl)cyclopentane-1-carboxylic acid
##STR00077##
[0345] Following the procedure as described in Example 1 (Step 4)
and making non-critical variations as required to replace ethyl
(1R,2R)-2-(4-adamantan-1-yl)methoxy)-5-cyclopropyl-2-fluorobenzoyl)cyclop-
entane-1-carboxylate with ethyl
(1R,2R)-2-(4-((1-(2-chloro-5-(trifluoromethyl)benzyl)piperidin-4-yl)metho-
xy)-5-cyclopropyl-2-fluorobenzoyl)cyclopentane-1-carboxylate, the
title compound was obtained following trituration with
dichloromethane as a colorless solid (0.035 g, 99% yield): .sup.1H
NMR (300 MHz, DMSO-d.sub.6) .delta. 12.06 (br s, 1H), 10.57 (br s,
1H), 8.33 (br s, 1H), 7.95-7.55 (m, 2H), 7.26 (d, J=8.7 Hz, 1H),
6.93 (d, J=13.8 Hz, 1H), 4.48 (br s, 1H), 3.96 (d, J=5.4 Hz, 2H),
3.79 (q, J=7.8 Hz, 1H), 3.58-3.35 (m, 1H), 3.12 (q, J=7.8 Hz, 2H),
2.18-1.49 (m, 13H), 0.89-0.83 (m, 2H), 0.65-0.51 (m, 2H); MS (ES+)
m/z 584.1, 582.2 (M+1).
Example 14 Synthesis of
2-(4-adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)-thio)cyclopentanecar-
boxylic acid
##STR00078##
[0346] Step 1. Preparation of
1,2-bis(4-adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)disulfane
##STR00079##
[0348] To a solution of
1-[(4-bromo-2-chloro-5-fluoro-phenoxy)methyl]adamantane (0.40 g,
1.070 mmol) in tetrahydrofuran (2.14 mL, 0.5 M) under nitrogen at
0.degree. C., isopropylmagnesium chloride in tetrahydrofuran (0.59
mL, 1.177 mmol, 2 mol/L) was added dropwise. The reaction mixture
was allowed to warm to room temperature and ran for 30 minutes.
Sulfur (0.172 g, 5.352 mmol) was added to the reaction mixture. The
reaction was slightly exothermic and the solution turned a
saturated yellow-orange color. The reaction was ran overnight.
Lithium aluminum hydride in tetrahydrofuran (0.67 mL, 1.606 mmol,
2.4 mol/L) was added dropwise to the solution at 0.degree. C. The
reaction mixture was raised to room temperature and allowed to run
for 1.5 hours. The reaction mixture was then quenched with 1M HCl
(3 mL) followed by sodium bicarbonate (3 mL), and was extracted
with EtOAc (3.times., 20 mL). The organic layers were collected and
combined, dried with MgSO.sub.4, and concentrated to give a yellow
oil. The material was moved on to the next step as a crude
mixture.
Step 2. Preparation of
4-(adamantan-1-ylmethoxy)-5-chloro-2-fluorobenzenethiol
##STR00080##
[0350] To a solution of
1,2-bis(4-adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)disulfane
(0.349 mg, 0.535 mmol) in tetrahydrofuran (1.78 mL, 0.3 M) and
ethanol (0.89 mL, 0.6 M), sodium borohydride (0.041 g, 1.070 mmol)
was added portion-wise at 0.degree. C. The reaction mixture was
then warmed to room temperature and ran for 30 minutes. The
reaction was quenched with 1 M HCl to reach pH=7. The crude
solution was extracted with EtOAc (3.times., 10 mL) and the organic
layers were collected. The combined organic extracts was washed
with water and extracted with 1M KOH (10 mL). The combined aqueous
extracts was extracted once more with EtOAc (10 mL). The organic
layers were combined, dried with MgSO.sub.4, and concentrated to
give the desired thiol as a yellow oil (0.200 g, 57% yield): MS
(ES-) m/z: 325 (M-1).
Step 3. Preparation of methyl
2-(4-adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)thio)-cyclopentanecar-
boxylate
##STR00081##
[0352] To a solution of
4-(adamantan-1-ylmethoxy)-5-chloro-2-fluorobenzenethiol (0.10 g,
0.306 mmol) was added to piperidine (0.765 mL, 0.4 M) at room
temperature, methyl cyclopentene-1-carboxylate (0.116 g, 0.918
mmol) was added and the solution was heated to 70.degree. C. The
reaction was run overnight. The reaction was cooled to room
temperature, quenched with 1M HCl (1 mL), and extracted with EtOAc
(3.times., 10 mL). The organic layers were collected and combined,
dried with MgSO.sub.4, and purified by preparative TLC in 1%
EtOAc/Heptane to give the desired product as a mixture of
diastereomers (0.035 g, 25% yield): .sup.1H NMR (400 MHz,
CDCl.sub.3) .delta. 7.46 (d, J=7.6 Hz, 1H), 6.65 (dd, J=10.4, 5.2
Hz, 1H), 3.73-3.70 (m, 6H), 3.60 (s, 3H), 3.51 (d, J=2.4 Hz, 3H),
2.72 (dt, J=9.0, 6.9 Hz, 1H), 2.17-1.99 (m, 8H), 1.92-1.53 (m,
27H); MS (ES+) m/z: 453 (M+1), 475 (M+Na).
Step 4. Preparation of 2-((4-((3 r, 5r,
7r)-adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)thio)-cyclopentanecarb-
oxylic acid
##STR00082##
[0354] To a solution of
2-(4-adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)thio)-cyclopentanecar-
boxylate (0.0175 g, 0.0385 mmol) in tetrahydrofuran (0.15 mL,
0.25M) and water (0.15 mL, 0.25M) at 0.degree. C., lithium
hydroxide (0.0014 g, 0.057 mmol) was added. The reaction was raised
to room temperature, then heated to 50.degree. C. and ran
overnight. The reaction was cooled to room temperature and
concentrated. The crude mixture was diluted with water and the
mixture was acidified with 1M HCl solution to pH=2. A white solid
crashed out of the solution. The mixture was diluted with
dichloromethane (10 mL) and extracted with dichloromethane
(2.times., 10 mL). The organic layers were combined, dried with
MgSO.sub.4, filtered, concentrated and was purified by preparative
HPLC to give the desired product as a white solid (0.005 g, 27%
yield): .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 7.56 (d, J=7.6
Hz, 1H), 7.15 (d, J=10.9 Hz, 1H), 3.70 (q, J=6.8 Hz, 1H), 3.64 (s,
2H), 2.59-2.50 (m, 1H), 2.08-1.92 (m, 5H), 1.78-1.56 (m, 15H), 1.47
(ddt, J=12.6, 7.4, 6.3 Hz, 1H), 1.24 (s, 1H). MS (ES-) m/z: 437
(M-1).
Example 15 Synthesis of
+/-trans-2-(4-adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)-sulfonylcyc-
lopentanecarboxylic acid
##STR00083##
[0355] Step 1. Preparation of methyl
2-(4-adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)-sulfonylcyclopentane-
carboxylate
##STR00084##
[0357] To a solution of methyl
2-(4-(1-adamantylmethoxy)-5-chloro-2-fluoro-phenyl)-sulfanylcyclopentanec-
arboxylate (100 mg, 0.2208 mmol) in dichloromethane (0.1 M, 2.2 mL)
at 0.degree. C., sodium bicarbonate (0.056 g, 0.6623 mmol, 3
equiv.) was added. 3-chloroperoxybenzoic acid (0.148 g, 0.6623
mmol, 3 equiv.) was then added portion-wise. The solution first
turned a bright orange, then pale yellow color, and slowly a white
precipitate was formed. After 3 hours, the crude reaction was
diluted with 1N NaOH solution (5 mL) and dichloromethane (5 mL) and
was extracted with dichloromethane (3.times., 10 mL). The organic
layers were collected, concentrated, and moved to the next step as
a crude. m/z: 486 (M+1).
Step 2. Preparation of
+/-trans-2-(4-adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)-sulfonylcyc-
lopentanecarboxylic acid
##STR00085##
[0359] To a the crude methyl
2-(4-(1-adamantylmethoxy)-5-chloro-2-fluoro-phenyl)-sulfonyl-cyclopentane-
carboxylate (0.1071 mg, 0.2208 mmol) mixture in tetrahydrofuran
(1.1 mL, 0.2 M) and water (1.1 mL, 0.2M) lithium hydroxide (0.053
g, 2.208 mmol, 10 equiv.) was added. The reaction mixture was
heated to 50.degree. C. and ran overnight. It was found that in the
hydrolysis, all of the sulfone had epimerized to one isomer, most
likely the trans isomer as it is the more thermodynamically favored
product. The reaction was then cooled to room temperature and
acidified to pH=3 with 1M HCl. The crude was diluted with water (3
mL) and dichloromethane (3 mL) and was extracted with
dichloromethane (3.times., 5 mL). The organic layers were
collected, concentrated, and purified by preparative HPLC to give a
white solid (0.043 g, 41% yield). .sup.1H NMR (400 MHz,
DMSO-d.sub.6) .delta. 12.52 (s, 1H), 7.75 (d, J=7.2 Hz, 1H), 7.41
(d, J=12.0 Hz, 1H), 4.09 (dt, J=9.0, 6.6 Hz, 1H), 3.76 (s, 2H),
2.99 (dt, J=8.9, 6.7 Hz, 1H), 2.12-1.94 (m, 6H), 1.81-1.62 (m,
15H); MS (ES+) m/z: 471 (M+1).
Example 16 Synthesis of
+/-trans-2-(4-adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)-sulfinylcyc-
lopentanecarboxylic acid
##STR00086##
[0360] Step 1. Preparation of methyl
2-(4-adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)-sulfinylcyclopentane-
carboxylate
##STR00087##
[0362] To a solution of methyl
2-(4-(1-adamantylmethoxy)-5-chloro-2-fluoro-phenyl)-sulfanylcyclopentanec-
arboxylate (109 mg, 0.2406 mmol) in dichloromethane (0.1 M, 2.4 mL)
at 0.degree. C., sodium bicarbonate (0.022 g, 0.2647 mmol, 1.1
equiv.) was added. 3-chloroperoxybenzoic acid (0.059 g, 0.2647
mmol, 1.1 equiv.) was then added portion-wise. The solution first
turned a bright orange, then pale yellow color, and slowly a white
precipitate was formed. After 15 minutes, the crude reaction was
diluted with 1N NaOH solution (5 mL) and dichloromethane (5 mL) and
was extracted with dichloromethane (3.times., 10 mL). The organic
layers were collected, concentrated, and moved to the next step as
a crude. m/z: 470 (M+1).
Step 2. Preparation of
+/-trans-2-(S)-(4-(adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)-sulfin-
ylcyclopentanecarboxylic acid and
+/-trans-2-(R)-(4-(adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)sulfiny-
lcyclopentanecarboxylic acid
##STR00088##
[0364] To a the crude methyl
2-(4-adamantan-1-ylmethoxy)-5-chloro-2-fluorophenyl)-sulfinylcyclopentane-
carboxylate (0.113 g, 0.2405 mmol) mixture in tetrahydrofuran (1.2
mL, 0.2 M) and water (1.2 mL, 0.2M) lithium hydroxide (0.058 g,
2.405 mmol, 10 equiv.) was added. The reaction mixture was heated
to 50.degree. C. and ran overnight. It was found that in the
hydrolysis, all of the sulfoxide had epimerized to one isomer, most
likely the trans isomer as it is the more thermodynamically favored
product. The reaction was then cooled to room temperature and
acidified to pH=3 with 1M HCl. The crude was diluted with water (3
mL) and dichloromethane (3 mL) and was extracted with
dichloromethane (3.times., 5 mL). The organic layers were
collected, concentrated, and purified by preparative HPLC to give
two sulfoxide diastereomers of the desired product as white solids.
.sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 7.48 (d, J=6.9 Hz, 1H),
7.26 (d, J=11.5 Hz, 1H), 3.67 (s, 3H), 2.93 (q, J=7.1 Hz, 1H), 2.15
(dq, J=15.5, 7.9, 6.9 Hz, 1H), 2.02-1.87 (m, 6H), 1.78-1.54 (m,
16H); .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 7.54 (d, J=7.0
Hz, 1H), 7.29 (d, J=11.5 Hz, 1H), 3.70 (s, 2H), 3.66-3.55 (m, 1H),
2.90 (q, J=7.6 Hz, 1H), 2.03-1.46 (m, 24H); m/z: 455 (M+1).
Example 17 Synthesis of
2-((4-adamant-1-ylmethoxy)-5-chloro-2-fluoro-anilino)cyclopentanecarboxyl-
ic acid
##STR00089##
[0365] Step 1. Preparation of ethyl
2-((4-adamant-1-ylmethoxy)-5-chloro-2-fluoro-anilino)cyclopentanecarboxyl-
ate
##STR00090##
[0367] In a heat dried microwave vial,
1-[(4-bromo-2-chloro-5-fluoro-phenoxy)methyl]adamantane (100 mg,
0.2676 mmol), ethyl 2-aminocyclopentanecarboxylate hydrochloride
(0.078 g, 0.4014 mmol, 1.5 equiv.), cesium carbonate (0.262 g.,
0.8028 mmol, 3 equiv.) and BrettPhos Pd G1 methyl-t-butyl ether
adduct (0.022, 0.02676 mmol, 10 mol %) were degassed with nitrogen.
Toluene (2.68 mL, 0.1M), which had been degassed, was added. The
reaction was refluxed overnight. The crude mixture was cooled to
room temperature, diluted with water and isopropyl acetate, and
extracted with isopropyl acetate 3.times. (5 mL). The organic
layers were collected, combined, and dried with MgSO.sub.4, and
purified by column chromatography to give the desired product as a
mixture of diastereomers, a pale yellow oil in 83% yield. .sup.1H
NMR (400 MHz, Chloroform-d) .delta. 6.96 (s, 1H), 6.88-6.72 (m,
2H), 6.65 (dd, J=12.6, 4.7 Hz, 1H), 4.02 (dddd, J=16.3, 11.0, 7.2,
3.9 Hz, 4H), 3.81 (s, 1H), 3.56 (s, 2H), 3.43 (s, 2H), 3.06 (q,
J=7.3 Hz, 1H), 2.97-2.87 (m, OH), 2.64 (ddd, J=8.8, 7.3, 5.8 Hz,
0H), 2.42 (p, J=6.8 Hz, 1H), 2.26-1.59 (m, 29H), 1.54 (s, 3H), 1.39
(d, J=13.2 Hz, 1H), 1.34-1.05 (m, 14H), 1.02-0.78 (m, 5H). MS (ES+)
m/z: 451 (M+1).
Step 2. Preparation of
2-((4-adamant-1-ylmethoxy)-5-chloro-2-fluoroanilino)-cyclopentanecarboxyl-
ic acid
##STR00091##
[0369] To a solution of ethyl
2-[4-(1-adamantylmethoxy)-5-chloro-2-fluoro-anilino]-cyclopentanecarboxyl-
ate (0.100 g, 0.2222 mmol) in tetrahydrofuran (0.89 mL, 0.25 M) and
water (0.89 mL, 0.25 M) at 0.degree. C., lithium hydroxide (0.053
g, 2.22 mmol, 10 equiv.) was added. The reaction was raised to room
temperature, then heated to 50.degree. C. and ran overnight. The
reaction was cooled to room temperature and concentrated. The crude
mixture was diluted with water and the mixture was acidified with
1M HCl solution to pH=2. A white solid crashed out of the solution.
The mixture was diluted with dichloromethane (5 mL) and extracted
with dichloromethane (2.times., 5 mL). The organic layers were
combined, dried with MgSO4, filtered, concentrated and was purified
by preparative HPLC to give the desired diastereomer products as
white solids (0.0019 g and 0.0022 g, 1.5% and 1.76% yield,
respectively). NMRs of the compounds were not able to be obtained
due to low yields. MS (ES-) m/z: 420 (M-1).
Example 18 Synthesis of
2-(4-(1-adamantylmethoxy)-5-chloro-2-fluoro-N-methylanilino)-cyclopentane-
carboxylic acid
##STR00092##
[0370] Step 1. Preparation of
2-(4-(1-adamantylmethoxy)-5-chloro-2-fluoro-N-methylanilino)-cyclopentane-
carboxylate
##STR00093##
[0372] To a solution of ethyl
2-(4-(1-adamantylmethoxy)-5-chloro-2-fluoroanilino)-cyclopentanecarboxyla-
te (0.070 g, 0.1556 mmol) in n,n-dimethylformamide (1.56 mL, 0.1
M), sodium hydride (0.008 g, 0.3111 mmol, 2 equiv.) was added and
the solution was stirred for 30 minutes. Iodomethane (0.096 mL,
1.56 mmol, 10 equiv.) was then added dropwise and the solution was
stirred for 2 days at room temperature. About 50% conversion to the
desired product was seen and presence of dimethylated product was
also seen. The reaction was quenched with 1M HCl (5 mL) and
extracted 3.times. with DCM (5 mL). The organic layers were
collected, combined, and concentrated. The crude mixture was
carried on to the next step as a crude. MS (ES+) m/z: 464 (M).
Step 2. Preparation of
2-(4-(1-adamantylmethoxy)-5-chloro-2-fluoro-N-methylanilino)-cyclopentane-
carboxylic acid
##STR00094##
[0374] To a solution of ethyl
2-[4-(1-adamantylmethoxy)-5-chloro-2-fluoro-N-methylanilino]-cyclopentane-
carboxylate (0.072 g, 0.156 mmol) in tetrahydrofuran (0.62 mL, 0.25
M) and water (0.62 mL, 0.25 M) at 0.degree. C., lithium hydroxide
(0.037 g, 1.56 mmol, 10 equiv.) was added. The reaction was raised
to room temperature, then heated to 50.degree. C. and ran
overnight. The reaction was cooled to room temperature and
concentrated. The crude mixture was diluted with water and the
mixture was acidified with 1M HCl solution to pH=2. A white solid
crashed out of the solution. There was only one stereoisomer seen
on the LC-MS, it was hypothesized that the stereochemistry
epimerized to trans, the thermodynamically favored product during
the hydrolysis. The mixture was diluted with dichloromethane (5 mL)
and extracted with dichloromethane (2.times., 5 mL). The organic
layers were combined, dried with MgSO4, filtered, concentrated and
was purified by preparative HPLC to give the desired product, with
hypothesized trans stereochemistry, as a white solid (0.0039 g,
5.63% yield): .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 7.12 (d,
J=8.8 Hz, 1H), 6.98 (d, J=13.7 Hz, 1H), 3.91 (q, J=7.3 Hz, 1H),
3.54 (s, 2H), 2.62 (s, 3H), 1.98 (s, 4H), 1.81-1.53 (m, 21H). MS
(ES-) m/z: 435 (M-1).
Example 19 Tritiated Compound Binding to Membranes Isolated from
Cells that Heterologously Express hNav1.7 and the .beta.1
Subunit
[0375] Preparation of membranes containing recombinantly expressed
sodium channels: Frozen recombinant cell pellets were thawed on ice
and diluted to 4 times the cell pellet weight with ice cold 50 mM
Tris HCl, pH 7.4 buffer. The cell suspensions were homogenized on
ice using a motorized glass dounce homogeniser. Homogenates were
further diluted 8.4 times with ice cold 50 mM Tris HCl, pH 7.4
buffer and then centrifuged at 200.times.g at 4.degree. C. for 15
min. The supernatants were collected and centrifuged at
10000.times.g at 4.degree. C. for 50 min. The pellets were then
re-suspended in 100 mM NaCl, 20 mM Tris HCl, pH 7.4 buffer
containing 1% v/v protease inhibitors (Calbiochem) and
re-homogenized on ice. The homogenized membranes were then
processed through a syringe equipped with a 26 gauge needle.
Protein concentrations were determined by Bradford Assay and the
membranes were stored at -80.degree. C.
[0376] Radioligand Binding Studies:
[0377] Saturation experiments. A competitive NaV1.7 inhibitor
having a methyl group was tritiated. Three tritiums were
incorporated in place of methyl hydrogens to generate
[.sup.3H]compound. Binding of this radioligand was performed in 5
mL borosilicate glass test tubes at room temperature. Binding was
initiated by adding membranes to increasing concentrations of
[.sup.3H]compound in 100 mM NaCl, 20 mM Tris HCl, pH 7.4 buffer
containing 0.01% w/v bovine serum albumin (BSA) for 18h.
Non-specific binding was determined in the presence of 1 .mu.M
unlabeled compound. After 18h, the reactants were filtered through
GF/C glass fiber filters presoaked in 0.5% w/v polyethylene imine.
Filters were washed with 15 mL ice cold 100 mM NaCl, 20 mM Tris
HCl, pH7.4 buffer containing 0.25% BSA to separate bound from free
ligand. [.sup.3H]compound bound to filters was quantified by liquid
scintillation counting.
[0378] Competitive Binding Experiments:
[0379] Binding reactions were performed in 96-well polypropylene
plates at room temperature for 18h. In 360 .mu.L, membranes were
incubated with 100 pM [.sup.3H]compound and increasing
concentrations of Test Compound. Non-specific binding was defined
in the presence of 1 .mu.M unlabeled compound. Reactions were
transferred and filtered through 96-well glass fiber/C filter
plates presoaked with 0.5% polyethylene imine. The filtered
reactions were washed 5 times with 200 .mu.L ice cold buffer
containing 0.25% BSA. Bound radioactivity was determined by liquid
scintillation counting.
Data Analysis: For saturation experiments, non-specific binding was
subtracted from total binding to provide specific binding and these
values were recalculated in terms of pmol ligand bound per mg
protein. Saturation curves were constructed and dissociation
constants were calculated using the single site ligand binding
model: Beq=(Bmax*X)/(X+Kd), where Beq is the amount of ligand bound
at equilibrium, Bmax is the maximum receptor density, Kd is the
dissociation constant for the ligand, and X is the free ligand
concentration. For competition studies percent inhibition was
determined and IC.sub.50 values were calculated using a 4 parameter
logistic model (% inhibition=(A+((B-A)/(1+((x/C) D)))) using XLfit,
where A and B are the maximal and minimum inhibition respectively,
C is the IC.sub.50 concentration and D is the (Hill) slope.
[0380] Representative compounds, when tested in this model,
demonstrated affinities as set forth in Table 1.
TABLE-US-00001 TABLE 1 Na.sub.v1.7 (LBA) Example Structure (.mu.M)
1 ##STR00095## 0.009 2 ##STR00096## 0.51 3 ##STR00097## 4.2 4
##STR00098## 0.44 5 ##STR00099## 3.1 6 ##STR00100## 0.055 7
##STR00101## 0.76 8 ##STR00102## 0.86 9 ##STR00103## 0.051 10
##STR00104## 0.021 11 ##STR00105## 0.7 12 ##STR00106## 0.003 13
##STR00107## 0.021 14 ##STR00108## 2.63 15 ##STR00109## 0.454 16
##STR00110## 1.29 17 ##STR00111## 3.02 18 ##STR00112## >10
Example 19
Analgesia Induced by Sodium Channel Blockers
Heat Induced Tail Flick Latency Test
[0381] In this test, the analgesia effect produced by administering
a compound of the invention can be observed through heat-induced
tail-flick in mice. The test includes a heat source consisting of a
projector lamp with a light beam focused and directed to a point on
the tail of a mouse being tested. The tail-flick latencies, which
are assessed prior to drug treatment, and in response to a noxious
heat stimulus, i.e., the response time from applying radiant heat
on the dorsal surface of the tail to the occurrence of tail flick,
are measured and recorded at 40, 80, 120, and 160 minutes.
[0382] For the first part of this study, 65 animals undergo
assessment of baseline tail flick latency once a day over two
consecutive days. These animals are then randomly assigned to one
of the 11 different treatment groups including a vehicle control, a
morphine control, and 9 compounds at 30 mg/Kg are administered
intramuscularly. Following dose administration, the animals are
closely monitored for signs of toxicity including tremor or
seizure, hyperactivity, shallow, rapid or depressed breathing and
failure to groom. The optimal incubation time for each compound is
determined via regression analysis. The analgesic activity of the
test compounds is expressed as a percentage of the maximum possible
effect (% MPE) and is calculated using the following formula:
% MPE Postdrug latency - Predrug latency Cut - off time ( 10 s ) -
Predrug latency .times. 100 % ##EQU00001##
where:
[0383] Postdrug latency=the latency time for each individual animal
taken before the tail is removed (flicked) from the heat source
after receiving drug.
[0384] Predrug latency=the latency time for each individual animal
taken before the tail is flicked from the heat source prior to
receiving drug.
[0385] Cut-off time (10 s)=is the maximum exposure to the heat
source.
[0386] Acute Pain (Formalin Test)
[0387] The formalin test is used as an animal model of acute pain.
In the formalin test, animals are briefly habituated to the
plexiglass test chamber on the day prior to experimental day for 20
minutes. On the test day, animals are randomly injected with the
test articles. At 30 minutes after drug administration, 50 .mu.L of
10% formalin is injected subcutaneously into the plantar surface of
the left hind paw of the rats. Video data acquisition begins
immediately after formalin administration, for duration of 90
minutes.
[0388] The images are captured using the Actimetrix Limelight
software which stores files under the *.llii extension, and then
converts it into the MPEG-4 coding. The videos are then analyzed
using behaviour analysis software "The Observer 5.1", (Version 5.0,
Noldus Information Technology, Wageningen, The Netherlands). The
video analysis is conducted by watching the animal behaviour and
scoring each according to type, and defining the length of the
behaviour (Dubuisson and Dennis, 1977). Scored behaviours include:
(1) normal behaviour, (2) putting no weight on the paw, (3) raising
the paw, (4) licking/biting or scratching the paw. Elevation,
favoring, or excessive licking, biting and scratching of the
injected paw indicate a pain response. Analgesic response or
protection from compounds is indicated if both paws are resting on
the floor with no obvious favoring, excessive licking, biting or
scratching of the injected paw.
[0389] Analysis of the formalin test data is done according to two
factors: (1) Percent Maximal Potential Inhibitory Effect (% MPIE)
and (2) pain score. The % MPIEs is calculated by a series of steps,
where the first is to sum the length of non-normal behaviours
(behaviours 1,2,3) of each animal. A single value for the vehicle
group is obtained by averaging all scores within the vehicle
treatment group. The following calculation yields the MPIE value
for each animal:
MPIE (%)=100-[(treatment sum/average vehicle value).times.100%]
[0390] The pain score is calculated from a weighted scale as
described above. The duration of the behaviour is multiplied by the
weight (rating of the severity of the response), and divided by the
total length of observation to determine a pain rating for each
animal. The calculation is represented by the following
formula:
Pain rating=[0(To)+1(T1)+2(T2)+3(T3)]/(To+T1+T2+T3)
[0391] CFA Induced Chronic Inflammatory Pain
[0392] In this test, tactile allodynia is assessed with calibrated
von Frey filaments. Following a full week of acclimatization to the
vivarium facility, 150 .mu.L of the "Complete Freund's Adjuvant"
(CFA) emulsion (CFA suspended in an oil/saline (1:1) emulsion at a
concentration of 0.5 mg/mL) is injected subcutaneously into the
plantar surface of the left hind paw of rats under light isoflurane
anaesthesia. Animals are allowed to recover from the anaesthesia
and the baseline thermal and mechanical nociceptive thresholds of
all animals are assessed one week after the administration of CFA.
All animals are habituated to the experimental equipment for 20
minutes on the day prior to the start of the experiment. The test
and control articles are administrated to the animals, and the
nociceptive thresholds measured at defined time points after drug
administration to determine the analgesic responses to each of the
six available treatments. The time points used are previously
determined to show the highest analgesic effect for each test
compound.
[0393] Thermal nociceptive thresholds of the animals are assessed
using the Hargreaves test. Animals are placed in a Plexiglas
enclosure set on top of an elevated glass platform with heating
units. The glass platform is thermostatically controlled at a
temperature of approximately 30.degree. C. for all test trials.
Animals are allowed to accommodate for 20 minutes following
placement into the enclosure until all exploration behaviour
ceases. The Model 226 Plantar/Tail Stimulator Analgesia Meter
(IITC, Woodland Hills, Calif.) is used to apply a radiant heat beam
from underneath the glass platform to the plantar surface of the
hind paws. During all test trials, the idle intensity and active
intensity of the heat source are set at 1 and 45 respectively, and
a cut off time of 20 seconds is employed to prevent tissue
damage.
[0394] The response thresholds of animals to tactile stimuli are
measured using the Model 2290 Electrovonfrey anesthesiometer (IITC
Life Science, Woodland Hills, Calif.) following the Hargreaves
test. Animals are placed in an elevated Plexiglas enclosure set on
a mire mesh surface. After 10 minutes of accommodation,
pre-calibrated Von Frey hairs are applied perpendicularly to the
plantar surface of both paws of the animals in an ascending order
starting from the 0.1 g hair, with sufficient force to cause slight
buckling of the hair against the paw. Testing continues until the
hair with the lowest force to induce a rapid flicking of the paw is
determined or when the cut off force of approximately 20 g is
reached. This cut off force is used because it represent
approximately 10% of the animals' body weight and it serves to
prevent raising of the entire limb due to the use of stiffer hairs,
which would change the nature of the stimulus.
Postoperative Models of Nociception
[0395] In this model, the hypealgesia caused by an intra-planar
incision in the paw is measured by applying increased tactile
stimuli to the paw until the animal withdraws its paw from the
applied stimuli. While animals are anaesthetized under 3.5%
isofluorane, which is delivered via a nose cone, a 1 cm
longitudinal incision is made using a number 10 scalpel blade in
the plantar aspect of the left hind paw through the skin and
fascia, starting 0.5 cm from the proximal edge of the heel and
extending towards the toes. Following the incision, the skin is
apposed using 2, 3-0 sterilized silk sutures. The injured site is
covered with Polysporin and Betadine. Animals are returned to their
home cage for overnight recovery.
[0396] The withdrawal thresholds of animals to tactile stimuli for
both operated (ipsilateral) and unoperated (contralateral) paws can
be measured using the Model 2290 Electrovonfrey anesthesiometer
(IITC Life Science, Woodland Hills, Calif.). Animals are placed in
an elevated Plexiglas enclosure set on a mire mesh surface. After
at least 10 minutes of acclimatization, pre-calibrated Von Frey
hairs are applied perpendicularly to the plantar surface of both
paws of the animals in an ascending order starting from the 10 g
hair, with sufficient force to cause slight buckling of the hair
against the paw. Testing continues until the hair with the lowest
force to induce a rapid flicking of the paw is determined or when
the cut off force of approximately 20 g is reached. This cut off
force is used because it represent approximately 10% of the
animals' body weight and it serves to prevent raising of the entire
limb due to the use of stiffer hairs, which would change the nature
of the stimulus.
Neuropathic Pain Model; Chronic Constriction Injury
[0397] Briefly, an approximately 3 cm incision is made through the
skin and the fascia at the mid thigh level of the animals' left
hind leg using a no. 10 scalpel blade. The left sciatic nerve is
exposed via blunt dissection through the biceps femoris with care
to minimize haemorrhagia. Four loose ligatures are tied along the
sciatic nerve using 4-0 non-degradable sterilized silk sutures at
intervals of 1 to 2 mm apart. The tension of the loose ligatures is
tight enough to induce slight constriction of the sciatic nerve
when viewed under a dissection microscope at a magnification of 4
fold. In the sham-operated animal, the left sciatic nerve is
exposed without further manipulation. Antibacterial ointment is
applied directly into the wound, and the muscle is closed using
sterilized sutures. Betadine is applied onto the muscle and its
surroundings, followed by skin closure with surgical clips.
[0398] The response thresholds of animals to tactile stimuli are
measured using the Model 2290 Electrovonfrey anesthesiometer (IITC
Life Science, Woodland Hills, Calif.). Animals are placed in an
elevated Plexiglas enclosure set on a mire mesh surface. After 10
minutes of accommodation, pre-calibrated Von Frey hairs are applied
perpendicularly to the plantar surface of both paws of the animals
in an ascending order starting from the 0.1 g hair, with sufficient
force to cause slight buckling of the hair against the paw. Testing
continues until the hair with the lowest force to induce a rapid
flicking of the paw is determined or when the cut off force of
approximately 20 g is reached. This cut off force is used because
it represents approximately 10% of the animals' body weight and it
serves to prevent raising of the entire limb due to the use of
stiffer hairs, which would change the nature of the stimulus.
[0399] Thermal nociceptive thresholds of the animals are assessed
using the Hargreaves test. Following the measurement of tactile
thresholds, animals are placed in a Plexiglass enclosure set on top
of an elevated glass platform with heating units. The glass
platform is thermostatically controlled at a temperature of
approximately 24 to 26.degree. C. for all test trials. Animals are
allowed to accommodate for 10 minutes following placement into the
enclosure until all exploration behaviour ceases. The Model 226
Plantar/Tail Stimulator Analgesia Meter (IITC, Woodland Hills,
Calif.) is used to apply a radiant heat beam from underneath the
glass platform to the plantar surface of the hind paws. During all
test trials, the idle intensity and active intensity of the heat
source are set at 1 and 55 respectively, and a cut off time of 20
seconds is used to prevent tissue damage.
Neuropathic Pain Model: Spinal Nerve Ligation
[0400] The spinal nerve ligation (SNL) neuropathic pain model is
used as an animal (i.e. rat) model of neuropathic pain. In the SNL
test, the lumbar roots of spinal nerves L5 and L6 are tightly
ligated to cause nerve injury, which results in the development of
mechanical hyperalgesia, mechanical allodynia and thermal
hypersensitivity. The surgery is performed two weeks before the
test day in order for the pain state to fully develop in the
animals. Several spinal nerve ligation variations are used to
characterize the analgesic properties of a compound of the
invention.
[0401] Ligation of the L5 spinal nerve;
[0402] Ligation of the L5 and L6 spinal nerves;
[0403] Ligation and transection of the L5 spinal nerve;
[0404] Ligation and transection of the L5 and L6 spinal nerves;
or
[0405] Mild irritation of the L4 spinal nerve in combination with
any one of the above (1)-(4).
[0406] While the animals are anaesthetized under 3.5% isofluorane
delivered via a nose cone, an approximately 2.5 cm longitudinal
incision is made using a number 10 scalpel blade in the skin just
lateral to the dorsal midline, using the level of the posterior
iliac crests as the midpoint of the incision. Following the
incision, the isoflourane is readjusted to maintenance levels
(1.5%-2.5%). At mid-sacral region, an incision is made with the
scalpel blade, sliding the blade along the side of the vertebral
column (in the saggital plane) until the blade hits the sacrum.
Scissors tips are introduced through the incision and the muscle
and ligaments are removed from the spine to expose 2-3 cm of the
vertebral column. The muscle and fascia are cleared from the spinal
vertebra in order to locate the point where the nerve exits from
the vertebra. A small glass hook is placed medial to the spinal
nerves and the spinal nerves are gently elevated from the
surrounding tissues. Once the spinal nerves have been isolated, a
small length of non-degradable 6-0 sterilized silk thread is wound
twice around the ball at the tip of the glass hook and passed back
under the nerve. The spinal nerves are then firmly ligated by tying
a knot, ensuring that the nerve bulges on both sides of the
ligature. The procedure may be repeated as needed. In some animals,
the L4 spinal nerve may be lightly rubbed (up to 20 times) with the
small glass hook to maximize the development of neuropathic pain.
Antibacterial ointment is applied directly into the incision, and
the muscle is closed using sterilized sutures. Betadine is applied
onto the muscle and its surroundings, followed by skin closure with
surgical staples or sterile non-absorable monofilament 5-0 nylon
sutures.
[0407] The analgesic effect produced by topical administration of a
compound of the invention to the animals can then be observed by
measuring the paw withdrawal threshold of animals to mechanical
tactile stimuli. These may be measured using either the mechanical
allodynia procedure or the mechanical hyperalgesia procedure as
described below. After establishment of the appropriate baseline
measurements by either method, topical formulation of a compound of
the invention is applied on the ipsilateral ankle and foot. The
animals are then placed in plastic tunnels for 15 minutes to
prevent them from licking the treated area and removing the
compound. Animals are placed in the acrylic enclosure for 15
minutes before testing the ipsilateral paw by either of the methods
described below, and the responses are recorded at 0.5, 1.0 and 2.0
hour post treatment.
Mechanical Allodynia Method
[0408] The pain threshold of animals to mechanical alloydnia for
both operated and control animals can be measured approximately 14
days post-surgery using manual calibrated von Frey filaments as
follows. Animals are placed in an elevated plexiglass enclosure set
on a mire mesh surface. Animals are allowed to acclimate for 20-30
minutes. Pre-calibrated Von Frey hairs are applied perpendicularly
to the plantar surface of the ipsilateral paw of the animals
starting from the 2.0 g hair, with sufficient force to cause slight
buckling of the hair against the paw to establish the baseline
measurements. Stimuli are presented in a consecutive manner, either
in an ascending or descending order until the first change in
response is noted, after which four additional responses are
recorded for a total of six responses. The six responses measured
in grams are entered into a formula as described by Chaplan, S. R.
et al., J. Neurosci. Methods, 1994 July; 53(1):55-63, and a 50%
withdrawal threshold is calculated. This constitutes the mechanical
allodynia value.
Mechanical Hyperalgesia Method
[0409] The response thresholds of animals to tactile stimuli are
measured using the Model 2290 Electrovonfrey anesthesiometer (IITC
Life Science, Woodland Hills, Calif.). Animals are placed in an
elevated Plexiglas enclosure set on a wire mesh surface. After 15
minutes of accommodation in this enclosure, a von Frey hair is
applied perpendicularly to the plantar surface of the ipsilateral
hind paws of the animals, with sufficient force, measured in grams,
to elicit a crisp response of the paw. A response indicates a
withdrawal from the painful stimulus and constitutes the efficacy
endpoint. The data are expressed as percent change from baseline
threshold measured in grams.
Example 20 In Vivo Assay for Treatment of Pruritis
[0410] The compounds of the invention can be evaluated for their
activity as antipruritic agents by in vivo test using rodent
models. One established model for peripherally elicited pruritus is
through the injection of serotonin into the rostral back area
(neck) in hairless rats. Prior to serotonin injections (e.g., 2
mg/mL, 50 .mu.L), a dose of a compound of the present invention can
be applied systemically through oral, intravenous or
intraperitoneal routes or topically to a circular area fixed
diameter (e.g. 18 mm). Following dosing, the serotonin injections
are given in the area of the topical dosing. After serotonin
injection the animal behaviour is monitored by video recording for
20 min-1.5 h, and the number of scratches in this time compared to
vehicle treated animals. Thus, application of a compound of the
current invention could suppress serotonin-induced scratching in
rats.
[0411] All of the U.S. patents, U.S. patent application
publications, U.S. patent applications, foreign patents, foreign
patent applications and non patent publications referred to in this
specification are incorporated herein by reference in their
entireties.
[0412] Although the foregoing invention has been described in some
detail to facilitate understanding, it will be apparent that
certain changes and modifications may be practiced within the scope
of the appended claims. Accordingly, the described embodiments are
to be considered as illustrative and not restrictive, and the
invention is not to be limited to the details given herein, but may
be modified within the scope and equivalents of the appended
claims.
* * * * *