U.S. patent application number 09/788173 was filed with the patent office on 2002-02-14 for cyclopropyl-fused pyrrolidine-based inhibitors of dipeptidyl peptidase iv and method.
Invention is credited to Augeri, David J., Betebenner, David A., Hamann, Lawrence G., Magnin, David R., Robl, Jeffrey A., Sulsky, Richard B..
Application Number | 20020019411 09/788173 |
Document ID | / |
Family ID | 22693638 |
Filed Date | 2002-02-14 |
United States Patent
Application |
20020019411 |
Kind Code |
A1 |
Robl, Jeffrey A. ; et
al. |
February 14, 2002 |
Cyclopropyl-fused pyrrolidine-based inhibitors of dipeptidyl
peptidase IV and method
Abstract
Dipeptidyl peptidase IV (DP 4) inhibiting compounds are provided
having the formula 1 where x is 0 or 1 and y is 0 or 1 (provided
that x=1 when y=0 and x=0 when y=1); n is 0 or 1; X is H or CN; and
wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as described
herein. A method is also provided for treating diabetes and related
diseases, especially Type II diabetes, and other diseases as set
out herein, employing such DP 4 inhibitor or a combination of such
DP 4 inhibitor and one or more of another antidiabetic agent such
as metformin, glyburide, troglitazone, pioglitazone, rosiglitazone
and/or insulin and/or one or more of a hypolipidemic agent and/or
anti-obesity agent and/or other therapeutic agent.
Inventors: |
Robl, Jeffrey A.; (Newtown,
PA) ; Sulsky, Richard B.; (West Trenton, NJ) ;
Augeri, David J.; (Princeton, NJ) ; Magnin, David
R.; (Hamilton, NJ) ; Hamann, Lawrence G.;
(Cherry Hill, NJ) ; Betebenner, David A.;
(Lawrenceville, NJ) |
Correspondence
Address: |
MARLA J MATHIAS
BRISTOL-MYERS SQUIBB COMPANY
PATENT DEPARTMENT
P O BOX 4000
PRINCETON
NJ
08543-4000
US
|
Family ID: |
22693638 |
Appl. No.: |
09/788173 |
Filed: |
February 16, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60188555 |
Mar 10, 2000 |
|
|
|
Current U.S.
Class: |
514/299 ;
546/112 |
Current CPC
Class: |
A61P 15/08 20180101;
A61P 5/50 20180101; A61P 3/06 20180101; A61P 37/06 20180101; A61P
19/10 20180101; A61P 5/06 20180101; A61P 31/18 20180101; C07C
2603/74 20170501; A61P 3/08 20180101; A61P 25/18 20180101; A61P
9/10 20180101; A61P 37/02 20180101; A61P 29/00 20180101; A61P 1/00
20180101; A61P 3/10 20180101; C07C 271/22 20130101; C07D 403/06
20130101; A61P 15/00 20180101; A61P 3/00 20180101; C07D 209/52
20130101; A61P 19/02 20180101; A61P 1/04 20180101; A61P 37/00
20180101; C07D 401/06 20130101; A61P 3/04 20180101; A61P 43/00
20180101 |
Class at
Publication: |
514/299 ;
546/112 |
International
Class: |
A61K 031/435; C07D
221/02 |
Claims
What is claimed is:
1. A compound having the structure 213herein x is 0 or 1 and y is 0
or 1, provided that x=1 when y=0 and x=0 when y=1; and wherein n is
0 or 1; X is H or CN; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the
same or different and are independently selected from hydrogen,
alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, bicycloalkyl,
tricycloalkyl, alkylcycloalkyl, hydroxyalkyl,
hydroxyalkylcycloalkyl, hydroxycycloalkyl, hydroxybicycloalkyl,
hydroxytricycloalkyl, bicycloalkylalkyl, alkylthioalkyl,
arylalkylthioalkyl, cycloalkenyl, aryl, aralkyl, heteroaryl,
heteroarylalkyl, cycloheteroalkyl or cycloheteroalkylalkyl; all
optionally substituted through available carbon atoms with 1, 2, 3,
4 or 5 groups selected from hydrogen, halo, alkyl, polyhaloalkyl,
alkoxy, haloalkoxy, polyhaloalkoxy, alkoxycarbonyl, alkenyl,
alkynyl, cycloalkyl, cycloalkylalkyl, polycycloalkyl,
heteroarylamino, arylamino, cycloheteroalkyl,
cycloheteroalkylalkyl, hydroxy, hydroxyalkyl, nitro, cyano, amino,
substituted amino, alkylamino, dialkylamino, thiol, alkylthio,
alkylcarbonyl, acyl, alkoxycarbonyl, aminocarbonyl,
alkynylaminocarbonyl, alkylaminocarbonyl, alkenylaminocarbonyl,
alkylcarbonyloxy, alkylcarbonylamino, arylcarbonylamino,
alkylsulfonylamino, alkylaminocarbonylamino, alkoxycarbonylamino,
alkylsulfonyl, aminosulfinyl, aminosulfonyl, alkylsulfinyl,
sulfonamido or sulfonyl; and R.sup.1 and R.sup.3 may optionally be
taken together to form --(CR.sup.5R.sup.6).sub.m-- where m is 2 to
6, and R.sup.5 and R.sup.6 are the same or different and are
independently selected from hydroxy, alkoxy, H, alkyl, alkenyl,
alkynyl, cycloalkyl, halo, amino, substituted amino,
cycloalkylalkyl, cycloalkenyl, aryl, arylalkyl, heteroaryl,
heteroarylalkyl, cycloheteroalkyl, cycloheteroalkylalkyl,
alkylcarbonylamino, arylcarbonylamino, alkoxycarbonylamino,
aryloxycarbonylamino, alkoxycarbonyl, aryloxycarbonyl, or
alkylaminocarbonylamino, or R.sup.1 and R.sup.4 may optionally be
taken together to form --(CR.sup.7R.sup.8).sub.p-- wherein p is 2
to 6, and R.sup.7 and R.sup.8 are the same or different and are
independently selected from hydroxy, alkoxy, cyano, H, alkyl,
alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, cycloalkenyl, halo,
amino, substituted amino, aryl, arylalkyl, heteroaryl,
heteroarylalkyl, cycloheteroalkyl, cycloheteroalkylalkyl,
alkylcarbonylamino, arylcarbonylamino, alkoxycarbonylamino,
aryloxycarbonylamino, alkoxycarbonyl, aryloxycarbonyl, or
alkylaminocarbonylamino, or optionally R.sup.1 and R.sup.3 together
with 214from a 5 to 7 membered ring containing a total of 2 to 4
heteroatoms selected from N, O, S, SO, or SO.sub.2; or optionally
R.sup.1 and R.sup.3 together with 215form a 4 to 8 membered
cycloheteroalkyl ring wherein the cycloheteroalkyl ring has an
optional aryl ring fused thereto or an optional 3 to 7 membered
cycloalkyl ring fused thereto; including all stereoisomers thereof;
and a pharmaceutically acceptable salt thereof, or a prodrug ester
thereof, and all stereoisomers thereof.
2. The compound as defined in claim 1 having the structure: 216
3. The compound as defined in claim 1 having the structure: 217
4. The compound as defined in claim 1 having the structure: 218
5. The compound as defined in claim 1 having the structure: 219
6. The compound as defined in claim 1 wherein: R.sup.3 is H,
R.sup.1 is H, alkyl, cycloalkyl, bicycloalkyl, tricycloalkyl,
alkylcycloalkyl, hydroxyalkyl, hydroxyalkylcycloalkyl,
hydroxycycloalkyl hydroxybicycloalkyl, or hydroxytricycloalkyl,
R.sup.2 is H or alkyl, n is 0, X is CN.
7. The compound as defined in claim 1 wherein the cyclopropyl fused
to the pyrrolidine has the configuration: 220
8. The compound as defined in claim 1 having the structure: 221or a
pharmaceutically acceptable salt thereof.
9. The compound as defined in claim 8 wherein the pharmaceutically
acceptable salt is the hydrochloride salt or the trifluoroacetic
acid salt.
10. The compound as defined in claim 1 which is 222wherein R.sup.1
is alkyl, cycloalkyl, bicycloalkyl, tricycloalkyl, alkylcycloalkyl,
hydroxyalkyl, hydroxycycloalkyl, hydroxyalkylcycloalkyl,
hydroxybicycloalkyl, or hydroxytricycloalkyl, or 223wherein R.sup.1
is alkyl, cycloalkyl, bicycloalkyl, tricycloalkyl, alkylcycloalkyl,
hydroxyalkyl, hydroxycycloalkyl, hydroxyalkylcycloalkyl,
hydroxybicycloalkyl, or hydroxytricycloalkyl.
11. A pharmaceutical composition comprising a compound as defined
in claim 1 and a pharmaceutically acceptable carrier therefor.
12. A pharmaceutical combination comprising a DP4 inhibitor
compound as defined in claim 1 and an antidiabetic agent other than
a DP4 inhibitor for treating diabetes and related diseases, an
anti-obesity agent and/or a lipid-modulating agent.
13. The pharmaceutical combination as defined in claim 12
comprising said DP4 inhibitor compound and an antidiabetic
agent.
14. The combination as defined in claim 13 wherein the antidiabetic
agent is 1, 2, 3 or more of a biguanide, a sulfonyl urea, a
glucosidase inhibitor, a PPAR .gamma. agonist, a PPAR
.alpha./.gamma. dual agonist, an SGLT2 inhibitor, an aP2 inhibitor,
a glycogen phosphorylase inhibitor, an AGE inhibitor, an insulin
sensitizer, a glucagon-like peptide-1 (GLP-1) or mimetic thereof,
insulin and/or a meglitinide.
15. The combination as defined in claim 14 wherein the antidiabetic
agent is 1, 2, 3 or more of metformin, glyburide, glimepiride,
glipyride, glipizide, chlorpropamide, gliclazide, acarbose,
miglitol, pioglitazone, troglitazone, rosiglitazone, insulin,
Gl-262570, isaglitazone, JTT-501, NN-2344, L895645, YM-440,
R-119702, AJ9677, repaglinide, nateglinide, KAD1129, AR-H039242,
GW-409544, KRP297, AC2993, Exendin-4, LY307161, NN2211, and/or
LY315902.
16. The combination as defined in claim 13 wherein the compound is
present in a weight ratio to the antidiabetic agent within the
range from about 0.01 to about 100:1.
17. The combination as defined in claim 12 wherein the anti-obesity
agent is a beta 3 adrenergic agonist, a lipase inhibitor, a
serotonin (and dopamine) reuptake inhibitor, a thyroid receptor
beta compound, an anorectic agent, and/or a fatty acid oxidation
upregulator.
18. The combination as defined in claim 17 wherein the anti-obesity
agent is orlistat, ATL-962, AJ9677, L750355, CP331648, sibutramine,
topiramate, axokine, dexamphetamine, phentermine,
phenylpropanolamine, famoxin, and/or mazindol.
19. The combination as defined in claim 12 wherein the lipid
modulating agent is an MTP inhibitor, an HMG CoA reductase
inhibitor, a squalene synthetase inhibitor, a fibric acid
derivative, an upregulator of LDL receptor activity, a lipoxygenase
inhibitor, an ACAT inhibitor, a cholesteryl ester transfer protein
inhibitor, or an ATP citrate lyase inhibitor.
20. The combination as defined in claim 19 wherein the lipid
modulating agent is pravastatin, lovastatin, simvastatin,
atorvastatin, cerivastatin, fluvastatin, nisvastatin, visastatin,
fenofibrate, gemfibrozil, clofibrate, implitapide, CP-529,414,
avasimibe, TS-962, MD-700, and/or LY295427.
21. The combination as defined in claim 19 wherein the DP4
inhibitor is present in a weight ratio to the lipid-modulating
agent within the range from about 0.01 to about 100:1.
22. A pharmaceutical combination comprising a DP4 inhibitor
compound as defined in claim 1 and an agent for treating
infertility, an agent for treating polycystic ovary syndrome, an
agent for treating a growth disorder and/or frailty, an
anti-arthritis agent, an agent for preventing inhibiting allograft
rejection in transplantation, an agent for treating autoimmune
disease, an anti-AIDS agent, an agent for treating inflammatory
bowel disease/syndrome, an agent for treating anorexia nervosa, an
anti-osteoporosis agent and/or an anti-obesity agent.
23. A method for treating diabetes, insulin resistance,
hyperglycemia, hyperisulinemia, or elevated blood levels of free
fatty acids or glycerol, obesity, Syndrome X, dysmetabolic
syndrome, diabetic complications, hypertriglyceridemia,
hyperinsulinemia, atherosclerosis, impaired glucose homeostasis,
impaired glucose tolerance, infertility, polycystic ovary syndrome,
growth disorders, frailty, arthritis, allograft rejection in
transplantation, autoimmune diseases, AIDS, intestinal diseases,
inflammatory bowel syndrome, nervosa, osteoporosis, or an
immunomodulatory disease or a chronic inflammatory bowel disease,
which comprises administering to a mammalian species in need of
treatment a therapeutically effective amount of a compound as
defined in claim 1.
24. The method as defined in claim 23 for treating type II diabetes
and/or obesity.
Description
[0001] This application takes priority from U.S. provisional
application No. 60/188,555, filed Mar. 10, 2000.
FIELD OF THE INVENTION
[0002] The present invention relates to cyclopropyl-fused
pyrrolidine-based inhibitors of dipeptidyl peptidase IV (DP-4), and
to a method for treating diabetes, especially Type II diabetes, as
well as hyperglycemia, Syndrome X, diabetic complications,
hyperinsulinemia, obesity, atherosclerosis and related diseases, as
well as various immunomodulatory diseases and chronic inflammatory
bowel disease, employing such cyclopropyl-fused pyrrolidines alone
or in combination with another type antidiabetic agent and/or other
type therapeutic agent.
BACKGROUND OF THE INVENTION
[0003] Depeptidyl peptidase IV (DP-4) is a membrane bound
non-classical serine aminodipeptidase which is located in a variety
of tissues (intestine, liver, lung, kidney) as well as on
circulating T-lymphocytes (where the enzyme is known as CD-26). It
is responsible for the metabolic cleavage of certain endogenous
peptides (GLP-1(7-36), glucagon) in vivo and has demonstrated
proteolytic activity against a variety of other peptides (GHRH,
NPY, GLP-2, VIP) in vitro.
[0004] GLP-1(7-36) is a 29 amino-acid peptide derived by
post-translational processing of proglucagon in the small
intestine. GLP-1(7-36) has multiple actions in vivo including the
stimulation of insulin secretion, inhibition of glucagon secretion,
the promotion of satiety, and the slowing of gastric emptying.
Based on its physiological profile, the actions of GLP-1(7-36) are
expected to be beneficial in the prevention and treatment of type
II diabetes and potentially obesity. To support this claim,
exogenous administration of GLP-1(7-36) (continuous infusion) in
diabetic patients has demonstrated efficacy in this patient
population. Unfortunately GLP-1(7-36) is degraded rapidly in vivo
and has been shown to have a short half-life in vivo
(t1/2.about.1.5 min). Based on a study of genetically bred DP-4 KO
mice and on in vivo/in vitro studies with selective DP-4
inhibitors, DP-4 has been shown to be the primary degrading enzyme
of GLP-1(7-36) in vivo. GLP-1(7-36) is degraded by DP-4 efficiently
to GLP-1(9-36), which has been speculated to act as a physiological
antagonist to GLP-1(7-36). Thus, inhibition of DP-4 in vivo should
potentiate endogenous levels of GLP-1(7-36) and attenuate formation
of its antagonist GLP-1(9-36) and thus serve to ameliorate the
diabetic condition.
DESCRIPTION OF THE INVENTION
[0005] In accordance with the present invention, cyclopropyl-fused
pyrrolidine-based compounds are provided which inhibit DP-4 and
have the structure I 2
[0006] wherein x is 0 or 1 and y is 0 or 1 (provided that x=1 when
y=0 and x=0 when y=1);
[0007] n is 0 or 1;
[0008] X is H or CN (that is cyano);
[0009] R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or
different and are independently selected from H, alkyl, alkenyl,
alkynyl, cycloalkyl, cycloalkylalkyl, bicycloalkyl, tricycloalkyl,
alkylcycloalkyl, hydroxyalkyl, hydroxyalkylcycloalkyl,
hydroxycycloalkyl, hydroxybicycloalkyl, hydroxytricycloalkyl,
bicycloalkylalkyl, alkylthioalkyl, arylalkylthioalkyl,
cycloalkenyl, aryl, aralkyl, heteroaryl, heteroarylalkyl,
cycloheteroalkyl and cycloheteroalkylalkyl, all optionally
substituted through available carbon atoms with 1, 2, 3, 4 or 5
groups selected from hydrogen, halo, alkyl, polyhaloalkyl, alkoxy,
haloalkoxy, polyhaloalkoxy, alkoxycarbonyl, alkenyl, alkynyl,
cycloalkyl, cycloalkylalkyl, polycycloalkyl, heteroarylamino,
arylamino, cycloheteroalkyl, cycloheteroalkylalkyl, hydroxy,
hydroxyalkyl, nitro, cyano, amino, substituted amino, alkylamino,
dialkylamino, thiol, alkylthio, alkylcarbonyl, acyl,
alkoxycarbonyl, aminocarbonyl, alkynylaminocarbonyl,
alkylaminocarbonyl, alkenylaminocarbonyl, alkylcarbonyloxy,
alkylcarbonylamino, arylcarbonylamino, alkylsulfonylamino,
alkylaminocarbonylamino, alkoxycarbonylamino, alkylsulfonyl,
aminosulfonyl, alkylsulfinyl, sulfonamido or sulfonyl;
[0010] and R.sup.1 and R.sup.3 may optionally be taken together to
form --(CR.sup.5R.sup.6).sub.m-where m is 2 to 6, and R.sup.5 and
R.sup.5 are the same or different and are independently selected
from hydroxy, alkoxy, cyano, H, alkyl, alkenyl, alkynyl,
cycloalkyl, cycloalkylalkyl, cycloalkenyl, aryl, arylalkyl,
heteroaryl, heteroarylalkyl, cycloheteroalkyl, halo, amino,
substituted amino, cycloheteroalkylalkyl, alkylcarbonylamino,
arylcarbonylamino, alkoxycarbonylamino, aryloxycarbonylamino,
alkoxycarbonyl, aryloxycarbonyl, or alkylaminocarbonylamino, or
R.sup.1 and R.sup.4 may optionally be taken together to form
--(CR.sup.7R.sup.8).sub.p-where p is 2 to 6, and R.sup.7 and
R.sup.8 are the same or different and are independently selected
from hydroxy, alkoxy, cyano, H, alkyl, alkenyl, alkynyl,
cycloalkyl, cycloalkylalkyl, cycloalkenyl, aryl, arylalkyl,
heteroaryl, heteroarylalkyl, cycloheteroalkyl, halo, amino,
substituted amino, cycloheteroalkylalkyl, alkylcarbonylamino,
arylcarbonylamino, alkoxycarbonylamino, aryloxycarbonylamino,
alkoxycarbonyl, aryloxycarbonyl, or alkylaminocarbonylamino, or
optionally R.sup.1 and R.sup.3 together with 3
[0011] form a 5 to 7 membered ring containing a total of 2 to 4
heteroatoms selected from N, O, S, SO, or SO.sub.2;
[0012] or optionally R.sup.1 and R.sup.3 together with 4
[0013] form a 4 to 8 membered cycloheteroalkyl ring wherein the
cycloheteroalkyl ring has an optional aryl ring fused thereto or an
optional 3 to 7 membered cycloalkyl ring fused thereto;
[0014] and including pharmaceutically acceptable salts thereof, and
prodrug esters thereof, and all stereoisomers thereof.
[0015] Thus, the compounds of formula I of the invention include
the following structures 5
[0016] In addition, in accordance with the present invention, a
method is provided for treating diabetes, especially Type II
diabetes, as well as impaired glucose homeostasis, impaired glucose
tolerance, infertility, polycystic ovary syndrome, growth
disorders, frailty, arthritis, allograft rejection in
transplantation, autoimmune diseases (such as scleroderma and
multiple sclerosis), various immunomodulatory diseases (such as
lupus erythematosis or psoriasis), AIDS, intestinal diseases (such
as necrotizing enteritis, microvillus inclusion disease or celiac
disease), inflammatory bowel syndrome, chemotherapy-induced
intestinal mucosal atrophy or injury, anorexia nervosa,
osteoporosis, Syndrome X, dysmetabolic syndrome, diabetic
complications, hyperinsulinemia, obesity, atherosclerosis and
related diseases, as well as inflammatory bowel disease(such as
Crohn's disease and ulcerative colitis), wherein a therapeutically
effective amount of a compound of structure I (which inhibits DP 4)
is administered to a human patient in need of treatment.
[0017] The conditions, diseases, and maladies collectively
referenced to as "Syndrome X" or Metabolic Syndrome are detailed in
Johannsson J. Clin. Endocrinol. Metab., 82, 727-734 (1997).
[0018] In addition, in accordance with the present invention, a
method is provided for treating diabetes and related diseases as
defined above and hereinafter as well as any of the other disease
states mentioned above, wherein a therapeutically effective amount
of a combination of a compound of structure I and one, two, three
or more of other types of antidiabetic agent(s) (which may be
employed to treat diabetes and related diseases) and/or one, two or
three or more other types of therapeutic agent(s) is administered
to a human patient in need of treatment.
[0019] The term "diabetes and related diseases" refers to Type II
diabetes, Type I diabetes, impaired glucose tolerance, obesity,
hyperglycemia, Syndrome X, dysmetabolic syndrome, diabetic
complications, dysmetabolic syndrome, and hyperinsulinemia.
[0020] The conditions, diseases and maladies collectively referred
to as "diabetic complications" include retinopathy, neuropathy and
nephropathy, and other known complications of diabetes.
[0021] The term "other type(s) of therapeutic agents" as employed
herein refers to one or more antidiabetic agents (other than DP4
inhibitors of formula I), one or more anti-obesity agents, and/or
one or more lipid-modulating agents (including anti-atherosclerosis
agents), and/or one or more infertility agents, one or more agents
for treating polycystic ovary syndrome, one or more agents for
treating growth disorders, one or more agents for treating frailty,
one or more agents for treating arthritis, one or more agents for
preventing allograft rejection in transplantation, one or more
agents for treating autoimmune diseases, one or more anti-AIDS
agents, one or more anti-osteoporosis agents, one or more agents
for treating immunomodulatory diseases, one or more agents for
treating chronic inflammatory bowel disease or syndrome and/or one
or more agents for treating anorexia nervosa.
[0022] The term "lipid-modulating" agent as employed herein refers
to agents which lower LDL and/or raise HDL and/or lower
triglycerides and/or lower total cholesterol and/or other known
mechanisms for therapeutically treating lipid disorders.
[0023] In the above methods of the invention, the compound of
structure I will be employed in a weight ratio to the antidiabetic
agent or other type therapeutic agent (depending upon its mode of
operation) within the range from about 0.01:1 to about 500:1,
preferably from about 0.1:1 to about 100:1, more preferably from
about 0.2:1 to about 10:1.
[0024] Preferred are compounds of formula I wherein R.sup.3 is H or
alkyl, R.sup.1 is H, alkyl, cycloalkyl, bicycloalkyl,
tricycloalkyl, alkylcycloalkyl, hydroxyalkyl, hydroxytricycloalkyl,
hydroxycycloalkyl, hydroxybicycloalkyl, or hydroxyalkylcycloalkyl,
R.sup.2 is H or alkyl, n is 0, X is CN, x is 0 or 1 and y is 0 or
1.
[0025] Most preferred are preferred compounds of formula I as
described above where X is 6
[0026] and/or wherein the fused cyclopropyl group is identified as
7
[0027] Thus, preferred compounds of formula I of the invention will
include the moiety: 8
[0028] Particularly preferred are the following compounds: 9
[0029] wherein R.sup.1 is alkyl, cycloalkyl, bicycloalkyl,
tricycloalkyl, alkylcycloalkyl, hydroxyalkyl, hydroxycycloalkyl,
hydroxyalkylcycloalkyl, hydroxybicycloalkyl or
hydroxytricycloalkyl; 10
[0030] wherein R.sup.1 is alkyl, cycloalkyl, bicycloalkyl,
tricycloalkyl, hydroxybicycloalkyl, hydroxytricycloalkyl,
alkylcycloalkyl, hydroxyalkyl, hydroxycycloalkyl or
hydroxyalkylcycloalkyl as well as the following: 11
DETAILED DESCRIPTION OF THE INVENTION
[0031] Compounds of the structure I may be generated by the methods
as shown in the following reaction schemes and the description
thereof.
[0032] Referring to Reaction Scheme 1, compound 1, where PG.sub.1
is a common amine protecting group such as Boc, Cbz, or FMOC and
X.sup.1 is H or CO.sub.2R.sup.9 as set out below, may be generated
by methods as described herein or in the literature (for example
see Sagnard et al, Tet-Lett., 1995, 36, pp. 3148-3152, Tverezovsky
et al, Tetrahedron, 1997, 53, pp. 14773-14792, Hanessian et al,
Bioorg. Med. Chem. Lett., 1998, 8, p. 2123-2128). Removal of the
PG.sub.1 group by conventional methods (e.g. (1) TFA or HCl when
PG.sub.1 is Boc, or (2) H.sub.2/Pd/C, TMSI when PG.sub.1 is Cbz, or
(3) Et.sub.2NH when PG.sub.1 is (FMOC) affords the free amine 2.
Amine 2 may be coupled to various protected amino acids such as 3
(where PG.sub.2 can be any of the PG.sub.1 protecting groups) using
standard peptide coupling conditions (e.g. EDAC/HOAT,
i-BuCOCOC1/TEA, PyBop/NMM) to afford the corresponding dipeptide 4.
Removal of the amine protecting group PG.sub.2 provides compound Ia
of the invention where X=H.
[0033] In the case where X.sup.1=CO.sub.2R.sup.9 (where R.sup.9 is
alkyl or aralkyl groups such as methyl, ethyl, t-butyl, or benzyl),
the ester may be hydrolyzed under a variety of conditions, for
example with aqueous NaOH in a suitable solvent such as methanol,
THF, or dioxane, to provide the acid 5. Conversion of the acid
group to the primary carboxamide, affording 6, may be effected by
activation of the acid group (e.g. employing i-BuOCOC1/TEA or EDAC)
followed by treatment with NH.sub.3 or an ammonia equivalent in a
solvent such as dioxane, ether, or methanol. The amide
functionality may be converted to the nitrile group by a variety of
standard conditions (e.g. POCl.sub.3/pyridine/imidazole or cyanuric
chloride/DMF or trifluoroacetic anhydride, THF, pyridine) to give
7. Finally, removal of the PG.sub.2 protecting group similar to
above provides compound of the invention Ib.
[0034] In a different sequence (Scheme 2), compound 1 where X.sup.1
is CO.sub.2R.sup.9 may be saponified to the acid and subsequently
amidated as described above to give amide 8. Removal of the
PG.sub.1 group followed by peptide coupling to 3 affords compound
6, an intermediate in the synthesis of Ib.
[0035] Alternately, the carboxamide group in 8 may be converted to
the nitrile as described above to give compound 9. Deprotection of
PG.sub.1 affords 10 which may be subject to standard peptide
coupling conditions to afford 7, an intermediate in the synthesis
of Ib. Compound 10 may also be generated by oxidation of the amine
2 (e.g. NCS) followed by hydrolysis and subsequent cyanide
treatment. Compound 10 may be obtained as a mixture of
stereoisomers or a single isomer/diastereomer which may be
epimerized (employing conventional procedures) to afford a mixture
of stereoisomers. 12 13
[0036] In a like manner, .beta.-amino acids such as 14
[0037] may be coupled with 2, the free amine of 8, or 10 to give
the corresponding amides which may be converted to the .beta.-amino
acid derivatives of compound Ia or Ib following the same
chemistry.
[0038] Unless otherwise indicated, the term "lower alkyl", "alkyl"
or "alk" as employed herein alone or as part of another group
includes both straight and branched chain hydrocarbons, containing
1 to 20 carbons, preferably 1 to 10 carbons, more preferably 1 to 8
carbons, in the normal chain, such as methyl, ethyl, propyl,
isopropyl, butyl, t-butyl, isobutyl, pentyl, hexyl, isohexyl,
heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethyl-pentyl, nonyl,
decyl, undecyl, dodecyl, the various branched chain isomers
thereof, and the like as well as such groups including 1 to 4
substituents such as halo, for example F, Br, Cl or I or CF.sub.3,
alkyl, alkoxy, aryl, aryloxy, aryl(aryl) or diaryl, arylalkyl,
arylalkyloxy, alkenyl, cycloalkyl, cycloalkylalkyl,
cycloalkylalkyloxy, amino, hydroxy, hydroxyalkyl, acyl, heteroaryl,
heteroaryloxy, heteroarylalkyl, heteroarylalkoxy, aryloxyalkyl,
alkylthio, arylalkylthio, aryloxyaryl, alkylamido, alkanoylamino,
arylcarbonylamino, nitro, cyano, thiol, haloalkyl, trihaloalkyl
and/or alkylthio.
[0039] Unless otherwise indicated, the term "cycloalkyl" as
employed herein alone or as part of another group includes
saturated or partially unsaturated (containing 1 or 2 double bonds)
cyclic hydrocarbon groups containing 1 to 3 rings, including
monocyclic alkyl, bicyclic alkyl (or bicycloalkyl) and tricyclic
alkyl (tricycloalkyl), containing a total of 3 to 20 carbons
forming the ring, preferably 3 to 10 carbons, forming the ring and
which may be fused to 1 or 2 aromatic rings as described for aryl,
which includes cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,
cycloheptyl, cyclooctyl, cyclodecyl and cyclododecyl, cyclohexenyl,
adamantyl, 15
[0040] any of which groups may be optionally substituted with 1 to
4 substituents such as halogen, alkyl, alkoxy, hydroxy, aryl,
aryloxy, arylalkyl, cycloalkyl, hydroxyalkyl, alkylamido,
alkanoylamino, oxo, acyl, arylcarbonylamino, amino, nitro, cyano,
thiol and/or alkylthio and/or any of the substituents for
alkyl.
[0041] The term "cycloalkenyl" as employed herein alone or as part
of another group refers to cyclic hydrocarbons containing 3 to 12
carbons, preferably 5 to 10 carbons and 1 or 2 double bonds.
Exemplary cycloalkenyl groups include cyclopentenyl, cyclohexenyl,
cycloheptenyl, cyclooctenyl, cyclohexadienyl, and cycloheptadienyl,
which may be optionally substituted as defined for cycloalkyl.
[0042] The term "cycloalkylene" as employed herein refers to a
"cycloalkyl" group which includes free bonds and thus is a linking
group such as 16
[0043] and the like, and may optionally be substituted as defined
above for "cycloalkyl".
[0044] The term "alkanoyl" as used herein alone or as part of
another group refers to alkyl linked to a carbonyl group.
[0045] Unless otherwise indicated, the term "lower alkenyl" or
"alkenyl" as used herein by itself or as part of another group
refers to straight or branched chain radicals of 2 to 20 carbons,
preferably 2 to 12 carbons, and more preferably 1 to 8 carbons in
the normal chain, which include one to six double bonds in the
normal chain, such as vinyl, 2-propenyl, 3-butenyl, 2-butenyl,
4-pentenyl, 3-pentenyl, 2-hexenyl, 3-hexenyl, 2-heptenyl,
3-heptenyl, 4-heptenyl, 3-octenyl, 3-nonenyl, 4-decenyl,
3-undecenyl, 4-dodecenyl, 4,8,12-tetradecatrienyl, and the like,
and which may be optionally substituted with 1 to 4 substituents,
namely, halogen, haloalkyl, alkyl, alkoxy, alkenyl, alkynyl, aryl,
arylalkyl, cycloalkyl, amino, hydroxy, heteroaryl,
cycloheteroalkyl, alkanoylamino, alkylamido, arylcarbonyl-amino,
nitro, cyano, thiol, alkylthio and/or any of the alkyl substituents
set out herein.
[0046] Unless otherwise indicated, the term "lower alkynyl" or
"alkynyl" as used herein by itself or as part of another group
refers to straight or branched chain radicals of 2 to 20 carbons,
preferably 2 to 12 carbons and more preferably 2 to 8 carbons in
the normal chain, which include one triple bond in the normal
chain, such as 2-propynyl, 3-butynyl, 2-butynyl, 4-pentynyl,
3-pentynyl, 2-hexynyl, 3-hexynyl, 2-heptynyl, 3-heptynyl,
4-heptynyl, 3-octynyl, 3-nonynyl, 4-decynyl, 3-undecynyl,
4-dodecynyl and the like, and which may be optionally substituted
with 1 to 4 substituents, namely, halogen, haloalkyl, alkyl,
alkoxy, alkenyl, alkynyl, aryl, arylalkyl, cycloalkyl, amino,
heteroaryl, cycloheteroalkyl, hydroxy, alkanoylamino, alkylamido,
arylcarbonylamino, nitro, cyano, thiol, and/or alkylthio, and/or
any of the alkyl substituents set out herein.
[0047] The terms "arylalkenyl" and "arylalkynyl" as used alone or
as part of another group refer to alkenyl and alkynyl groups as
described above having an aryl substituent.
[0048] Where alkyl groups as defined above have single bonds for
attachment to other groups at two different carbon atoms, they are
termed "alkylene" groups and may optionally be substituted as
defined above for "alkyl".
[0049] Where alkenyl groups as defined above and alkynyl groups as
defined above, respectively, have single bonds for attachment at
two different carbon atoms, they are termed "alkenylene groups" and
"alkynylene groups", respectively, and may optionally be
substituted as defined above for "alkenyl" and "alkynyl".
[0050] The term "halogen" or "halo" as used herein alone or as part
of another group refers to chlorine, bromine, fluorine, and iodine
as well as CF.sub.3, with chlorine or fluorine being preferred.
[0051] The term "metal ion" refers to alkali metal ions such as
sodium, potassium or lithium and alkaline earth metal ions such as
magnesium and calcium, as well as zinc and aluminum.
[0052] Unless otherwise indicated, the term "aryl" as employed
herein alone or as part of another group refers to monocyclic and
bicyclic aromatic groups containing 6 to 10 carbons in the ring
portion (such as phenyl or naphthyl including 1-naphthyl and
2-naphthyl) and may optionally include one to three additional
rings fused to a carbocyclic ring or a heterocyclic ring (such as
aryl, cycloalkyl, heteroaryl or cycloheteroalkyl rings for example
17
[0053] and may be optionally substituted through available carbon
atoms with 1, 2, or 3 groups selected from hydrogen, halo,
haloalkyl, alkyl, haloalkyl, alkoxy, haloalkoxy, alkenyl,
trifluoromethyl, trifluoromethoxy, alkynyl, cycloalkylalkyl,
cycloheteroalkyl, cycloheteroalkylalkyl, aryl, heteroaryl,
arylalkyl, aryloxy, aryloxyalkyl, arylalkoxy, arylthio, arylazo,
heteroarylalkyl, heteroarylalkenyl, heteroarylheteroaryl,
heteroaryloxy, hydroxy, nitro, cyano, amino, substituted amino
wherein the amino includes 1 or 2 substituents (which are alkyl,
aryl or any of the other aryl compounds mentioned in the
definitions), thiol, alkylthio, arylthio, heteroarylthio,
arylthioalkyl, alkoxyarylthio, alkylcarbonyl, arylcarbonyl,
alkylaminocarbonyl, arylaminocarbonyl, alkoxycarbonyl,
aminocarbonyl, alkylcarbonyloxy, arylcarbonyloxy,
alkylcarbonylamino, arylcarbonylamino, arylsulfinyl,
arylsulfinylalkyl, arylsulfonylamino or arylsulfon-aminocarbonyl
and/or any of the alkyl substituents set out herein.
[0054] Unless otherwise indicated, the term "lower alkoxy",
"alkoxy", "aryloxy" or "aralkoxy" as employed herein alone or as
part of another group includes any of the above alkyl, aralkyl or
aryl groups linked to an oxygen atom.
[0055] Unless otherwise indicated, the term "substituted amino" as
employed herein alone or as part of another group refers to amino
substituted with one or two substituents, which may be the same or
different, such as alkyl, aryl, arylalkyl, heteroaryl,
heteroarylalkyl, cycloheteroalkyl, cycloheteroalkylalkyl,
cycloalkyl, cycloalkylalkyl, haloalkyl, hydroxyalkyl, alkoxyalkyl
or thioalkyl. These substituents may be further substituted with
any of the R.sup.1 groups or substituents for R.sup.1 as set out
above. In addition, the amino substituents may be taken together
with the nitrogen atom to which they are attached to form
1-pyrrolidinyl, 1-piperidinyl, 1-azepinyl, 4-morpholinyl,
4-thiamorpholinyl, 1-piperazinyl, 4-alkyl-1-piperazinyl,
4-arylalkyl-1-piperazinyl, 4-diarylalkyl-1-piperazinyl,
1-pyrrolidinyl, 1-piperidinyl, or 1-azepinyl, optionally
substituted with alkyl, alkoxy, alkylthio, halo, trifluoromethyl or
hydroxy.
[0056] Unless otherwise indicated, the term "lower alkylthio",
alkylthio", "arylthio" or "aralkylthio" as employed herein alone or
as part of another group includes any of the above alkyl, aralkyl
or aryl groups linked to a sulfur atom.
[0057] Unless otherwise indicated, the term "lower alkylamino",
"alkylamino", "arylamino", or "arylalkylamino" as employed herein
alone or as part of another group includes any of the above alkyl,
aryl or arylalkyl groups linked to a nitrogen atom.
[0058] Unless otherwise indicated, the term "acyl" as employed
herein by itself or part of another group, as defined herein,
refers to an organic radical linked to a carbonyl 18
[0059] group; examples of acyl groups include any of the R.sup.1
groups attached to a carbonyl, such as alkanoyl, alkenoyl, aroyl,
aralkanoyl, heteroaroyl, cycloalkanoyl, cycloheteroalkanoyl and the
like.
[0060] Unless otherwise indicated, the term "cycloheteroalkyl" as
used herein alone or as part of another group refers to a 5-, 6- or
7-membered saturated or partially unsaturated ring which includes 1
to 2 hetero atoms such as nitrogen, oxygen and/or sulfur, linked
through a carbon atom or a heteroatom, where possible, optionally
via the linker (CH.sub.2) r (where r is 1, 2 or 3), such as: 19
[0061] and the like. The above groups may include 1 to 4
substituents such as alkyl, halo, oxo and/or any of the alkyl
substituents set out herein. In addition, any of the
cycloheteroalkyl rings can be fused to a cycloalkyl, aryl,
heteroaryl or cycloheteroalkyl ring.
[0062] Unless otherwise indicated, the term "heteroaryl" as used
herein alone or as part of another group refers to a 5- or
6-membered aromatic ring which includes 1, 2, 3 or 4 hetero atoms
such as nitrogen, oxygen or sulfur, and such rings fused to an
aryl, cycloalkyl, heteroaryl or cycloheteroalkyl ring (e.g.
benzothiophenyl, indolyl), and includes possible N-oxides. The
heteroaryl group may optionally include 1 to 4 substituents such as
any of the substituents set out above for alkyl. Examples of
heteroaryl groups include the following: 20
[0063] and the like.
[0064] The term "cycloheteroalkylalkyl" as used herein alone or as
part of another group refers to cycloheteroalkyl groups as defined
above linked through a C atom or heteroatom to a (CH.sub.2).sub.r
chain.
[0065] The term "heteroarylalkyl" or "heteroarylalkenyl" as used
herein alone or as part of another group refers to a heteroaryl
group as defined above linked through a C atom or heteroatom to a
--(CH.sub.2).sub.r-- chain, alkylene or alkenylene as defined
above.
[0066] The term "polyhaloalkyl" as used herein refers to an "alkyl"
group as defined above which includes from 2 to 9, preferably from
2 to 5, halo substituents, such as F or Cl, preferably F, such as
CF.sub.3CH.sub.2, CF.sub.3 or CF.sub.3CF.sub.2CH.sub.2.
[0067] The term "polyhaloalkoxy" as used herein refers to an
"alkoxy" or "alkyloxy" group as defined above which includes from 2
to 9, preferably from 2 to 5, halo substituents, such as F or Cl,
preferably F, such as CF.sub.3CH.sub.2O, CF.sub.3O or
CF.sub.3CF.sub.2CH.sub.2O.
[0068] All stereoisomers of the compounds of the instant invention
are contemplated, either in admixture or in pure or substantially
pure form. The compounds of the present invention can have
asymmetric centers at any of the carbon atoms including any one or
the R substituents. Consequently, compounds of formula I can exist
in enantiomeric or diastereomeric forms or in mixtures thereof. The
processes for preparation can utilize racemates, enantiomers or
diastereomers as starting materials. When diastereomeric or
enantiomeric products are prepared, they can be separated by
conventional methods for example, chromatographic or fractional
crystallization.
[0069] Where desired, the compounds of structure I may be used in
combination with one or more other types of antidiabetic agents
(employed to treat diabetes and related diseases) and/or one or
more other types of therapeutic agents which may be administered
orally in the same dosage form, in a separate oral dosage form or
by injection.
[0070] The other type of antidiabetic agent which may be optionally
employed in combination with the DP4 inhibitor of formula I may be
1,2,3 or more antidiabetic agents or antihyperglycemic agents
including insulin secretagogues or insulin sensitizers, or other
antidiabetic agents preferably having a mechanism of action
different from DP4 inhibition and may include biguanides, sulfonyl
ureas, glucosidase inhibitors, PPAR .gamma. agonists, such as
thiazolidinediones, SGLT2 inhibitors, PPAR .alpha./.gamma. dual
agonists, aP2 inhibitors, glycogen phosphorylase inhibitors,
advanced glycosylation end (AGE) products inhibitors, and/or
meglitinides, as well as insulin, and/or glucagon-like peptide-1
(GLP-1) or mimetics thereof.
[0071] It is believed that the use of the compounds of structure I
in combination with 1, 2, 3 or more other antidiabetic agents
produces antihyperglycemic results greater than that possible from
each of these medicaments alone and greater than the combined
additive anti-hyperglycemic effects produced by these
medicaments.
[0072] The other antidiabetic agent may be an oral
antihyperglycemic agent preferably a biguanide such as metformin or
phenformin or salts thereof, preferably metformin HCl.
[0073] Where the other antidiabetic agent is a biguanide, the
compounds of structure I will be employed in a weight ratio to
biguanide within the range from about 0.01:1 to about 100:1,
preferably from about 0.1:1 to about 5:1.
[0074] The other antidiabetic agent may also preferably be a
sulfonyl urea such as glyburide (also known as glibenclamide),
glimepiride (disclosed in U.S. Pat. No. 4,379,785), glipizide,
gliclazide or chlorpropamide, other known sulfonylureas or other
antihyperglycemic agents which act on the ATP-dependent channel of
the .beta.-cells, with glyburide and glipizide being preferred,
which may be administered in the same or in separate oral dosage
forms.
[0075] The compounds of structure I will be employed in a weight
ratio to the sulfonyl urea in the range from about 0.01:1 to about
100:1, preferably from about 0.05:1 to about 5:1.
[0076] The oral antidiabetic agent may also be a glucosidase
inhibitor such as acarbose (disclosed in U.S. Pat. No. 4,904,769)
or miglitol (disclosed in U.S. Pat. No. 4,639,436), which may be
administered in the same or in a separate oral dosage forms.
[0077] The compounds of structure I will be employed in a weight
ratio to the glucosidase inhibitor within the range from about
0.01:1 to about 100:1, preferably from about 0.2:1 to about
50:1.
[0078] The compounds of structure I may be employed in combination
with a PPAR .gamma. agonist such as a thiazolidinedione oral
anti-diabetic agent or other insulin sensitizers (which has an
insulin sensitivity effect in NIDDM patients) such as troglitazone
(Warner-Lambert's Rezulin.RTM., disclosed in U.S. Pat. No.
4,572,912), rosiglitazone (SKB), pioglitazone (Takeda),
Mitsubishi's MCC-555 (disclosed in U.S. Pat. No. 5,594,016),
Glaxo-Wellcome's GL-262570, englitazone (CP-68722, Pfizer) or
darglitazone (CP-86325, Pfizer, isaglitazone (MIT/J&J), JTT-501
(JPNT/P&U), L-895645 (Merck), R-119702 (Sankyo/WL), NN-2344
(Dr. Reddy/NN), or YM-440 (Yamanouchi), preferably rosiglitazone
and pioglitazone.
[0079] The compounds of structure I will be employed in a weight
ratio to the thiazolidinedione in an amount within the range from
about 0.01:1 to about 100:1, preferably from about 0.1:1 to about
10:1.
[0080] The sulfonyl urea and thiazolidinedione in amounts of less
than about 150 mg oral antidiabetic agent may be incorporated in a
single tablet with the compounds of structure I.
[0081] The compounds of structure I may also be employed in
combination with a antihyperglycemic agent such as insulin or with
glucagon-like peptide-1 (GLP-1) such as GLP-1(1-36) amide,
GLP-1(7-36) amide, GLP-1(7-37) (as disclosed in U.S. Pat. No.
5,614,492 to Habener, disclosure of which is incorporated herein by
reference), or a GLP-1 mimic such as AC2993 or Exendin-4 (Amylin)
and LY-315902 or LY-307167 (Lilly) and NN2211 (Novo-Nordisk), which
may be administered via injection, intranasal, or by transdermal or
buccal devices.
[0082] Where present, metformin, the sulfonyl ureas, such as
glyburide, glimepiride, glipyride, glipizide, chlorpropamide and
gliclazide and the glucosidase inhibitors acarbose or miglitol or
insulin (injectable, pulmonary, buccal, or oral) may be employed in
formulations as described above and in amounts and dosing as
indicated in the Physician's Desk Reference (PDR).
[0083] Where present, metformin or salt thereof may be employed in
amounts within the range from about 500 to about 2000 mg per day
which may be administered in single or divided doses one to four
times daily.
[0084] Where present, the thiazolidinedione anti-diabetic agent may
be employed in amounts within the range from about 0.01 to about
2000 mg/day which may be administered in single or divided doses
one to four times per day.
[0085] Where present insulin may be employed in formulations,
amounts and dosing as indicated by the Physician's Desk
Reference.
[0086] Where present GLP-1 peptides may be administered in oral
buccal formulations, by nasal administration (for example
inhalation spray) or parenterally as described in U.S. Pat. No.
5,346,701 (TheraTech), U.S. Pat. Nos. 5,614,492 and 5,631,224 which
are incorporated herein by reference.
[0087] The other antidiabetic agent may also be a PPAR
.alpha./.gamma. dual agonist such as AR-HO39242 (Astra/Zeneca),
GW-409544 (Glaxo-Wellcome), KRP297 (Kyorin Merck) as well as those
disclosed by Murakami et al, "A Novel Insulin Sensitizer Acts As a
Coligand for Peroxisome Proliferation--Activated Receptor Alpha
(PPAR alpha) and PPAR gamma. Effect on PPAR alpha Activation on
Abnormal Lipid Metabolism in Liver of Zucker Fatty Rats", Diabetes
47, 1841-1847 (1998), and in U.S. application Ser. No. 09/664,598,
filed Sep. 18, 2000, (attorney file LA29NP) the disclosure of which
is incorporated herein by reference, employing dosages as set out
therein, which compounds designated as preferred are preferred for
use herein.
[0088] The other antidiabetic agent may be an SGLT2 inhibitor such
as disclosed in U.S. application Ser. No. 09/679,027, filed Oct. 4,
2000 (attorney file LA49NP), which is incorporated herein by
reference, employing dosages as set out herein. Preferred are the
compounds designated as preferred in the above application.
[0089] The other antidiabetic agent which may be optionally
employed in combination with the DP4 inhibitor of formula I may be
an aP2 inhibitor such as disclosed in U.S. application Ser. No.
09/391,053, filed Sep. 7, 1999, and U.S. application Ser. No.
09/519,079, filed Mar. 6, 2000 (attorney file LA27NP), which is
incorporated herein by reference, employing dosages as set out
herein. Preferred are the compounds designated as preferred in the
above application.
[0090] The other antidiabetic agent which may be optionally
employed in combination with the DP4 inhibitor of formula I may be
a glycogen phosphorylase inhibitor such as disclosed in WO
96/39384, WO 96/39385, EP 978279, WO 2000/47206, WO 99/43663, and
U.S. Pat. Nos. 5,952,322 and 5,998,463, WO 99/26659 and EP
1041068.
[0091] The meglitinide which may optionally be employed in
combination with the compound of formula I of the invention may be
repaglinide, nateglinide (Novartis) or KAD1229 (PF/Kissei), with
repaglinide being preferred.
[0092] The DP4 inhibitor of formula I will be employed in a weight
ratio to the meglitinide, PPAR .gamma. agonist, PPAR
.alpha./.gamma. dual agonist, SGLT2 inhibitor, aP2 inhibitor, or
glycogen phosphorylase inhibitor within the range from about 0.01:1
to about 100:1, preferably from about 0.1:1 to about 10:1.
[0093] The hypolipidemic agent or lipid-modulating agent which may
be optionally employed in combination with the compounds of formula
I of the invention may include 1,2,3 or more MTP inhibitors, HMG
CoA reductase inhibitors, squalene synthetase inhibitors, fibric
acid derivatives, ACAT inhibitors, lipoxygenase inhibitors,
cholesterol absorption inhibitors, ileal Na.sup.+/bile acid
cotransporter inhibitors, upregulators of LDL receptor activity,
ATP citrate lyase inhibitors, cholesteryl ester transfer protein
inhibitors, bile acid sequestrants, and/or nicotinic acid and
derivatives thereof.
[0094] MTP inhibitors employed herein include MTP inhibitors
disclosed in U.S. Pat. No. 5,595,872, U.S. Pat. No. 5,739,135, U.S.
Pat. No. 5,712,279, U.S. Pat. No. 5,760,246, U.S. Pat. No.
5,827,875, U.S. Pat. No. 5,885,983 and U.S. application Ser. No.
09/175,180 filed Oct. 20, 1998, now U.S. Pat. No. 5,962,440.
Preferred are each of the preferred MTP inhibitors disclosed in
each of the above patents and applications.
[0095] All of the above U.S. patents and applications are
incorporated herein by reference.
[0096] Most preferred MTP inhibitors to be employed in accordance
with the present invention include preferred MTP inhibitors as set
out in U.S. Pat. Nos. 5,739,135 and 5,712,279, and U.S. Pat. No.
5,760,246 as well as implitapide (Bayer)
[0097] The most preferred MTP inhibitor is
9-[4-[4-[[2-(2,2,2-Trifluoroeth-
oxy)benzoyl]amino]-1-piperidinyl]butyl]-N-(2,2,2-trifluoroethyl)-9H-fluore-
ne-9-carboxamide 21
[0098] The hypolipidemic agent may be an HMG CoA reductase
inhibitor which includes, but is not limited to, mevastatin and
related compounds as disclosed in U.S. Pat. No. 3,983,140,
lovastatin (mevinolin) and related compounds as disclosed in U.S.
Pat. No. 4,231,938, pravastatin and related compounds such as
disclosed in U.S. Pat. No. 4,346,227, simvastatin and related
compounds as disclosed in U.S. Pat. Nos. 4,448,784 and 4,450,171.
Other HMG CoA reductase inhibitors which may be employed herein
include, but are not limited to, fluvastatin, disclosed in U.S.
Pat. No. 5,354,772, cerivastatin disclosed in U.S. Pat. Nos.
5,006,530 and 5,177,080, atorvastatin disclosed in U.S. Pat. Nos.
4,681,893, 5,273,995, 5,385,929 and 5,686,104, atavastatin
(Nissan/Sankyo's nisvastatin (NK-104)) disclosed in U.S. Pat. No.
5,011,930, Shionogi-Astra/Zeneca visastatin (ZD-4522) disclosed in
U.S. Pat. No. 5,260,440.
[0099] The squalene synthetase inhibitors suitable for use herein
include, but are not limited to, .alpha.-phosphono-sulfonates
disclosed in U.S. Pat. No. 5,712,396, those disclosed by Biller et
al, J. Med. Chem., 1988, Vol. 31, No. 10, pp 1869-1871, including
isoprenoid (phosphinylmethyl)phosphonates as well as other known
squalene synthetase inhibitors, for example, as disclosed in U.S.
Pat. No. 4,871,721 and 4,924,024 and in Biller, S. A.,
Neuenschwander, K., Ponpipom, M. M., and Poulter, C. D., Current
Pharmaceutical Design, 2, 1-40 (1996).
[0100] In addition, other squalene synthetase inhibitors suitable
for use herein include the terpenoid pyrophosphates disclosed by P.
Ortiz de Montellano et al, J. Med. Chem., 1977, 20, 243-249, the
farnesyl diphosphate analog A and presqualene pyrophosphate
(PSQ-PP) analogs as disclosed by Corey and Volante, J. Am. Chem.
Soc., 1976, 98, 1291-1293, phosphinylphosphonates reported by
McClard, R. W. et al, J.A.C.S., 1987, 109, 5544 and cyclopropanes
reported by Capson, T. L., PhD dissertation, June, 1987, Dept. Med.
Chem. U of Utah, Abstract, Table of Contents, pp 16, 17, 40-43,
48-51, Summary.
[0101] Other hypolipidemic agents suitable for use herein include,
but are not limited to, fibric acid derivatives, such as
fenofibrate, gemfibrozil, clofibrate, bezafibrate, ciprofibrate,
clinofibrate and the like, probucol, and related compounds as
disclosed in U.S. Patent No. 3,674,836, probucol and gemfibrozil
being preferred, bile acid sequestrants such as cholestyramine,
colestipol and DEAE-Sephadex (Secholex.RTM., Policexide.RTM.), as
well as lipostabil (Rhone-Poulenc), Eisai E-5050 (an N-substituted
ethanolamine derivative), imanixil (HOE-402), tetrahydrolipstatin
(THL), istigmastanylphosphorylcholine (SPC, Roche),
aminocyclodextrin (Tanabe Seiyoku), Ajinomoto AJ-814 (azulene
derivative), melinamide (Sumitomo), Sandoz 58-035, American
Cyanamid CL-277,082 and CL-283,546 (disubstituted urea
derivatives), nicotinic acid, acipimox, acifran, neomycin,
p-aminosalicylic acid, aspirin, poly(diallylmethylamine)
derivatives such as disclosed in U.S. Pat. No. 4,759,923,
quaternary amine poly(diallyldimethylammonium chloride) and ionenes
such as disclosed in U.S. Pat. No. 4,027,009, and other known serum
cholesterol lowering agents.
[0102] The other hypolipidemic agent may be an ACAT inhibitor such
as disclosed in, Drugs of the Future 24, 9-15 (1999), (Avasimibe);
"The ACAT inhibitor, Cl-1011 is effective in the prevention and
regression of aortic fatty streak area in hamsters", Nicolosi et
al, Atherosclerosis (Shannon, Irel). (1998), 137(1), 77-85; "The
pharmacological profile of FCE 27677: a novel ACAT inhibitor with
potent hypolipidemic activity mediated by selective suppression of
the hepatic secretion of ApoB100-containing lipoprotein", Ghiselli,
Giancarlo, Cardiovasc. Drug Rev. (1998), 16(1), 16-30; "RP 73163: a
bioavailable alkylsulfinyl-diphenylimidazole ACAT inhibitor",
Smith, C., et al, Bioorg. Med. Chem. Lett. (1996), 6(1), 47-50;
"ACAT inhibitors: physiologic mechanisms for hypolipidemic and
anti-atherosclerotic activities in experimental animals", Krause et
al, Editor(s): Ruffolo, Robert R., Jr.; Hollinger, Mannfred A.,
Inflammation: Mediators Pathways (1995), 173-98, Publisher: CRC,
Boca Raton, Fla.; "ACAT inhibitors: potential anti-atherosclerotic
agents", Sliskovic et al, Curr. Med. Chem. (1994), 1(3), 204-25;
"Inhibitors of acyl-CoA:cholesterol O-acyl transferase (ACAT) as
hypocholesterolemic agents. 6. The first water-soluble ACAT
inhibitor with lipid-regulating activity. Inhibitors of
acyl-CoA:cholesterol acyltransferase (ACAT). 7. Development of a
series of substituted
N-phenyl-N'-[(1-phenylcyclopentyl)methyl]ureas with enhanced
hypocholesterolemic activity", Stout et al, Chemtracts: Org. Chem.
(1995), 8(6), 359-62, or TS-962 (Taisho Pharmaceutical Co.
Ltd).
[0103] The hypolipidemic agent may be an upregulator of LD2
receptor activity such as MD-700 (Taisho Pharmaceutical Co. Ltd)
and LY295427 (Eli Lilly).
[0104] The hypolipidemic agent may be a cholesterol absorption
inhibitor preferably Schering-Plough's SCH48461 as well as those
disclosed in Atherosclerosis 115, 45-63 (1995) and J. Med. Chem.
41, 973 (1998).
[0105] The hypolipidemic agent may be an ileal Na.sup.+/bile acid
cotransporter inhibitor such as disclosed in Drugs of the Future,
24, 425-430 (1999).
[0106] The lipid-modulating agent may be a cholesteryl ester
transfer protein (CETP) inhibitor such as Pfizer's CP 529,414
(WO/0038722 and EP 818448) and Pharmacia's SC-744 and SC-795.
[0107] The ATP citrate lyase inhibitor which may be employed in the
combination of the invention may include, for example, those
disclosed in U.S. Pat. No. 5,447,954.
[0108] Preferred hypolipidemic agents are pravastatin, lovastatin,
simvastatin, atorvastatin, fluvastatin, cerivastatin, atavastatin
and ZD-4522.
[0109] The above-mentioned U.S. patents are incorporated herein by
reference. The amounts and dosages employed will be as indicated in
the Physician's Desk Reference and/or in the patents set out
above.
[0110] The compounds of formula I of the invention will be employed
in a weight ratio to the hypolipidemic agent (were present), within
the range from about 500:1 to about 1:500, preferably from about
100:1 to about 1:100.
[0111] The dose administered must be carefully adjusted according
to age, weight and condition of the patient, as well as the route
of administration, dosage form and regimen and the desired
result.
[0112] The dosages and formulations for the hypolipidemic agent
will be as disclosed in the various patents and applications
discussed above.
[0113] The dosages and formulations for the other hypolipidemic
agent to be employed, where applicable, will be as set out in the
latest edition of the Physicians' Desk Reference.
[0114] For oral administration, a satisfactory result may be
obtained employing the MTP inhibitor in an amount within the range
of from about 0.01 mg/kg to about 500 mg and preferably from about
0.1 mg to about 100 mg, one to four times daily.
[0115] A preferred oral dosage form, such as tablets or capsules,
will contain the MTP inhibitor in an amount of from about 1 to
about 500 mg, preferably from about 2 to about 400 mg, and more
preferably from about 5 to about 250 mg, one to four times
daily.
[0116] For oral administration, a satisfactory result may be
obtained employing an HMG CoA reductase inhibitor, for example,
pravastatin, lovastatin, simvastatin, atorvastatin, fluvastatin or
cerivastatin in dosages employed as indicated in the Physician's
Desk Reference, such as in an amount within the range of from about
1 to 2000 mg, and preferably from about 4 to about 200 mg.
[0117] The squalene synthetase inhibitor may be employed in dosages
in an amount within the range of from about 10 mg to about 2000 mg
and preferably from about 25 mg to about 200 mg.
[0118] A preferred oral dosage form, such as tablets or capsules,
will contain the HMG CoA reductase inhibitor in an amount from
about 0.1 to about 100 mg, preferably from about 5 to about 80 mg,
and more preferably from about 10 to about 40 mg.
[0119] A preferred oral dosage form, such as tablets or capsules
will contain the squalene synthetase inhibitor in an amount of from
about 10 to about 500 mg, preferably from about 25 to about 200
mg.
[0120] The other hypolipidemic agent may also be a lipoxygenase
inhibitor including a 15-lipoxygenase (15-LO) inhibitor such as
benzimidazole derivatives as disclosed in WO 97/12615, 15-LO
inhibitors as disclosed in WO 97/12613, isothiazolones as disclosed
in WO 96/38144, and 15-LO inhibitors as disclosed by Sendobry et al
"Attenuation of diet-induced atherosclerosis in rabbits with a
highly selective 15-lipoxygenase inhibitor lacking significant
antioxidant properties", Brit. J. Pharmacology (1997) 120,
1199-1206, and Cornicelli et al, "15-Lipoxygenase and its
Inhibition: A Novel Therapeutic Target for Vascular Disease",
Current Pharmaceutical Design, 1999, 5, 11-20.
[0121] The compounds of formula I and the hypolipidemic agent may
be employed together in the same oral dosage form or in separate
oral dosage forms taken at the same time.
[0122] The compositions described above may be administered in the
dosage forms as described above in single or divided doses of one
to four times daily. It may be advisable to start a patient on a
low dose combination and work up gradually to a high dose
combination.
[0123] The preferred hypolipidemic agent is pravastatin,
simvastatin, lovastatin, atorvastatin, fluvastatin or
cerivastatin.
[0124] The other type of therapeutic agent which may be optionally
employed with the DP4 inhibitor of formula I may be 1, 2, 3 or more
of an anti-obesity agent including a beta 3 adrenergic agonist, a
lipase inhibitor, a serotonin (and dopamine) reuptake inhibitor, a
thyroid receptor beta drug, an anorectic agent and/or a fatty acid
oxidation upregulator.
[0125] The beta 3 adrenergic agonist which may be optionally
employed in combination with a compound of formula I may be AJ9677
(Takeda/Dainippon), L750355 (Merck), or CP331648 (Pfizer) or other
known beta 3 agonists as disclosed in U.S. Pat. Nos. 5,541,204,
5,770,615, 5,491,134, 5,776,983 and 5,488,064, with AJ9677,
L750,355 and CP331648 being preferred.
[0126] The lipase inhibitor which may be optionally employed in
combination with a compound of formula I may be orlistat or ATL-962
(Alizyme), with orlistat being preferred.
[0127] The serotonin (and dopoamine) reuptake inhibitor which may
be optionally employed in combination with a compound of formula I
may be sibutramine, topiramate (Johnson & Johnson) or axokine
(Regeneron), with sibutramine and topiramate being preferred.
[0128] The thyroid receptor beta compound which may be optionally
employed in combination with a compound of formula I may be a
thyroid receptor ligand as disclosed in WO97/21993 (U. Cal SF),
W099/00353 (KaroBio) and GB98/284425 (KaroBio), with compounds of
the KaroBio applications being preferred.
[0129] The anorectic agent which may be optionally employed in
combination with a compound of formula I may be dexamphetamine,
phentermine, phenylpropanolamine or mazindol, with dexamphetamine
being preferred.
[0130] The fatty acid oxidation upregulator which may be optionally
employed in combination with the compound of formula I can be
famoxin (Genset).
[0131] The various anti-obesity agents described above may be
employed in the same dosage form with the compound of formula I or
in different dosage forms, in dosages and regimens as generally
known in the art or in the PDR.
[0132] The infertility agent which may be optionally employed in
combination with the DP4 inhibitor of the invention may be 1, 2, or
more of clomiphene citrate (Clomid.RTM., Aventis), bromocriptine
mesylate (Parlodel.RTM., Novartis), LHRH analogs, Lupron (TAP
Pharm.), danazol, Danocrine (Sanofi), progestogens or
glucocorticoids, which may be employed in amounts specified in the
PDR.
[0133] The agent for polycystic ovary syndrome which may be
optionally employed in combination with the DP4 inhibitor of the
invention may be 1, 2, or more of gonadotropin releasing hormone
(GnRH), leuprolide (Lupron.RTM.), Clomid.RTM., Parlodel.RTM., oral
contraceptives or insulin sensitizers such as PPAR agonists, or
other conventional agents for such use which may be employed in
amounts specified in the PDR.
[0134] The agent for treating growth disorders and/or frailty which
may be optionally employed in combination with the DP4 inhibitor of
the invention may be 1, 2, or more of a growth hormone or growth
hormone secretagogue such as MK-677 (Merck), CP-424,391 (Pfizer),
and compounds disclosed in U.S. Ser. No. 09/506,749 filed Feb. 18,
2000 (attorney docket LA26), as well as selective androgen receptor
modulators (SARMs), which is incorporated herein by reference,
which may be employed in amounts specified in the PDR, where
applicable.
[0135] The agent for treating arthritis which may be optionally
employed in combination with the DP4 inhibitor of the invention may
be 1, 2, or more of aspirin, indomethacin, ibuprofen, diclofenac
sodium, naproxen, nabumetone (Relafen.RTM., SmithKline Beecham),
tolmetin sodium (Tolectin.RTM., Ortho-McNeil), piroxicam
(Feldene.RTM., Pfizer), ketorolac tromethamine (Toradol.RTM.,
Roche), celecoxib (Celebrex.RTM., Searle), rofecoxib (Vioxx.RTM.,
Merck) and the like, which may be employed in amounts specified in
the PDR.
[0136] Conventional agents for preventing allograft rejection in
transplantation such as cyclosporin, Sandimmune (Novartis),
azathioprine, Immuran (Faro) or methotrexate may be optionally
employed in combination with the DP4 inhibitor of the invention,
which may be employed in amounts specified in the PDR.
[0137] Conventional agents for treating autoimmune diseases such as
multiple sclerosis and immunomodulatory diseases such as lupus
erythematosis, psoriasis, for example, azathioprine, Immuran,
cyclophosphamide, NSAIDS such as ibuprofen, cox 2 inhibitors such
as Vioxx and Celebrex, glucocorticoids and hydroxychloroquine, may
be optionally employed in combination with the DP4 inhibitor of the
invention, which may be employed in amounts specified in the
PDR.
[0138] The AIDS agent which may be optionally employed in
combination with the DP4 inhibitor of the invention may be a
non-nucleoside reverse transcriptase inhibitor, a nucleoside
reverse transcriptase inhibitor, a protease inhibitor and/or an
AIDS adjunct anti-infective and may be 1, 2, or more of dronabinol
(Marinol.RTM., Roxane Labs), didanosine (Videx.RTM., Bristol-Myers
Squibb), megestrol acetate (Megace.RTM., Bristol-Myers Squibb),
stavudine (Zerit.RTM., Bristol-Myers Squibb), delavirdine mesylate
(Rescriptor.RTM., Pharmacia), lamivudine/zidovudine (Combivir.TM.,
Glaxo), lamivudine (Epivir.TM., Glaxo), zalcitabine (Hivid.RTM.,
Roche), zidovudine (Retrovir.RTM., Glaxo), indinavir sulfate
(Crixivan.RTM., Merck), saquinavir (Fortovase.TM., Roche),
saquinovir mesylate (Invirase.RTM., Roche), ritonavir (Norvir.RTM.,
Abbott), nelfinavir (Viracept.RTM., Agouron).
[0139] The above anti-AIDS agents may be employed in amounts
specified in the PDR.
[0140] The agent for treating inflammatory bowel disease or
syndrome which may be optionally employed in combination with the
DP4 inhibitor of the invention may be 1, 2, or more of
sulfasalazine, salicylates, mesalamine (Asacol.RTM., P&G) or
Zelmac.RTM., (Bristol-Myers Squibb), which may be employed in
amounts specified in the PDR or otherwise known in the art.
[0141] The agent for treating osteoporosis which may be optionally
employed in combination with the DP4 inhibitor of the invention may
be 1, 2, or more of alendronate sodium (Fosamax.RTM., Merck,
tiludronate (Skelid.RTM., Sanofi), etidronate disodium
(Didronel.RTM., P&G), raloxifene HCl (Evista.RTM., Lilly),
which may be employed in amounts specified in the PDR.
[0142] In carrying our the method of the invention, a
pharmaceutical composition will be employed containing the
compounds of structure I, with or without another antidiabetic
agent and/or other type therapeutic agent, in association with a
pharmaceutical vehicle or diluent. The pharmaceutical composition
can be formulated employing conventional solid or liquid vehicles
or diluents and pharmaceutical additives of a type appropriate to
the mode of desired administration. The compounds can be
administered to mammalian species including humans, monkeys, dogs,
etc. by an oral route, for example, in the form of tablets,
capsules, granules or powders, or they can be administered by a
parenteral route in the form of injectable preparations. The dose
for adults is preferably between 10 and 1,000 mg per day, which can
be administered in a single dose or in the form of individual doses
from 1-4 times per day.
[0143] A typical capsule for oral administration contains compounds
of structure I (250 mg), lactose (75 mg) and magnesium stearate (15
mg). The mixture is passed through a 60 mesh sieve and packed into
a No. 1 gelatin capsule.
[0144] A typical injectable preparation is produced by aseptically
placing 250 mg of compounds of structure I into a vial, aseptically
freeze-drying and sealing. For use, the contents of the vial are
mixed with 2 mL of physiological saline, to produce an injectable
preparation.
[0145] DP4 inhibitor activity of the compounds of the invention may
be determined by use of an in vitro assay system which measures the
potentiation of inhibition of DP4. Inhibition constants (Ki values)
for the DP4 inhibitors of the invention may be determined by the
method described below.
[0146] Purification of Porcine Dipeptidyl Peptidase IV
[0147] Porcine enzyme was purified as previously described (1),
with several modifications. Kidneys from 15-20 animals were
obtained, and the cortex was dissected away and frozen at
-80.degree. C. Frozen tissue (2000-2500 g) was homogenized in 12 L
of 0.25 M sucrose in a Waring blender. The homogenate then was left
at 37.degree. C. for 18 hours to facilitate cleavage of DP-4 from
cell membranes. After the cleavage step, the homogenate was
clarified by centrifugation at 7000.times.g for 20 min at 4.degree.
C., and the supernatant was collected. Solid ammonium sulfate was
added to 60% saturation, and the precipitate was collected by
centrifugation at 10,000.times. g and was discarded. Additional
ammonium sulfate was added to the supernatant to 80% saturation,
and the 80% pellet was collected and dissolved in 20 mM
Na.sub.2HPO.sub.4, pH 7.4.
[0148] After dialysis against 20 mM Na.sub.2HPO.sub.4, pH 7.4, the
preparation was clarified by centrifugation at 10,000.times. g. The
clarified preparation then was applied to 300 mL of ConA Sepharose
that had been equilibrated in the same buffer. After washing with
buffer to a constant A.sub.280, the column was eluted with 5% (w/v)
methyl .alpha.-D-mannopyranoside. Active fractions were pooled,
concentrated, and dialyzed against 5 mM sodium acetate, pH 5.0.
Dialyzed material then was flowed through a 100 mL Pharmacia
Resource S column equilibrated in the same buffer. The flow through
material was collected and contained most of the enzyme activity.
Active material again was concentrated and dialyzed into 20 mM
Na.sub.2HPO.sub.4, pH 7.4. Lastly, the concentrated enzyme was
chromatographed on a Pharmacia S-200 gel filtration column to
removed low molecular weight contaminants. Purity of column
fractions was analyzed by reducing SDS-PAGE, and the purest
fractions were pooled and concentrated. Purified enzyme was stored
in 20% glycerol at -80.degree. C.
[0149] Assay of Porcine Dipeptidyl Peptidase IV
[0150] Enzyme was assayed under steady-state conditions as
previously described (2) with gly-pro-p-nitroanilide as substrate,
with the following modifications. Reactions contained, in a final
volume of 100 .mu.l, 100 mM Aces, 52 mM TRIS, 52 mM ethanolamine,
500 .mu.M gly-pro-p-nitroanilide, 0.2% DMSO, and 4.5 nM enzyme at
25.degree. C., pH 7.4. For single assays at 10 .mu.M test compound,
buffer, compound, and enzyme were added to wells of a 96 well
microtiter plate, and were incubated at room temperature for 5 min.
Reactions were started by addition of substrate. The continuous
production of p-nitroaniline was measured at 405 nM for 15 min
using a Molecular Devices Tmax plate reader, with a read every 9
seconds. The linear rate of p-nitroaniline production was obtained
over the linear portion of each progress curve. A standard curve
for p-nitroaniline absorbance was obtained at the beginning of each
experiment, and enzyme catalyzed p-nitroaniline production was
quantitated from the standard curve. Compounds giving greater than
50% inhibition were selected for further analysis.
[0151] For analysis of positive compounds, steady-state kinetic
inhibition constants were determined as a function of both
substrate and inhibitor concentration. Substrate saturation curves
were obtained at gly-pro-p-nitroanilide concentrations from 60
.mu.M to 3600 .mu.M. Additional saturation curves also were
obtained in the presence of inhibitor. Complete inhibition
experiments contained 11 substrate and 7 inhibitor concentrations,
with triplicate determinations across plates. For tight binding
inhibitors with Kis less than 20 nM, the enzyme concentration was
reduced to 0.5 nM and reaction times were increased to 120 min.
Pooled datasets from the three plates were fitted to the
appropriate equation for either competitive, noncompetitive or
uncompetitive inhibition.
[0152] (1) Rahfeld, J. Schutkowski, M., Faust, J., Neubert., Barth,
A., and Heins, J. (1991) Biol. Chem. Hoppe-Seyler, 372,
313-318.
[0153] (2) Nagatsu, T., Hino, M., Fuyamada, H., Hayakawa, T.,
Sakakibara, S., Nakagawa, Y., and Takemoto, T. (1976) Anal.
Biochem., 74, 466-476.
[0154] The following abbreviations are employed in the Examples and
elsewhere herein:
[0155] Ph=phenyl
[0156] Bn=benzyl
[0157] i-Bu=iso-butyl
[0158] Me=methyl
[0159] Et=ethyl
[0160] Pr=propyl
[0161] Bu=butyl
[0162] TMS=trimethylsilyl
[0163] FMOC=fluorenylmethoxycarbonyl
[0164] Boc or BOC=tert-butoxycarbonyl
[0165] Cbz=carbobenzyloxy or carbobenzoxy or benzyloxycarbonyl
[0166] HOAc or AcOH=acetic acid
[0167] DMF=N,N-dimethylformamide
[0168] EtOAc=ethyl acetate
[0169] THF=tetrahydrofuran
[0170] TFA=trifluoroacetic acid
[0171] Et.sub.2NH=diethylamine
[0172] NMM=N-methyl morpholine
[0173] n-BuLi=n-butyllithium
[0174] Pd/C=palladium on carbon
[0175] PtO.sub.2=platinum oxide
[0176] TEA=triethylamine
[0177] EDAC=3-ethyl-3'-(dimethylamino)propyl-carbodiimide
hydrochloride (or
1-[(3-(dimethyl)amino)propyl])-3-ethylcarbodiimide
hydrochloride)
[0178] HOBT or HOBT.H.sub.2O=1-hydroxybenzotriazole hydrate
[0179] HOAT=1-hydroxy-7-azabenzotriazole
[0180] PyBOP reagent=benzotriazol-1-yloxy-tripyrrolidino
phosphonium hexafluorophosphate
[0181] min=minute(s)
[0182] h or hr=hour(s)
[0183] L=liter
[0184] mL=milliliter
[0185] .mu.L=microliter
[0186] g=gram(s)
[0187] mg=milligram(s)
[0188] mol=mole(s)
[0189] mmol=millimole(s)
[0190] meq=milliequivalent
[0191] rt=room temperature
[0192] sat or sat'd=saturated
[0193] aq.=aqueous
[0194] TLC=thin layer chromatography
[0195] HPLC=high performance liquid chromatography
[0196] LC/MS=high performance liquid chromatography/mass
spectrometry
[0197] MS or Mass Spec=mass spectrometry
[0198] NMR=nuclear magnetic resonance
[0199] mp=melting point
[0200] The following Examples represent preferred embodiments of
the invention.
EXAMPLE 1
[0201] Step 1. 22
[0202] Step 1 title compound was synthesized by following the
literature procedure [Stephen Hanessian, Ulrich Reinhold, Michel
Saulnier, and Stephen Claridge; Bioorganic & Medicinal
Chemistry Letters 8 (1998) 2123-2128] or with the following
modifications. L-pyroglutamic acid ethyl ester was N-protected as
the t-butylcarbamate (Boc.sub.2O, DMAP or NaH) and then dehydrated
to the 4,5-dehydroproline ethyl ester in one pot by carbonyl
reduction (triethylborohydride, toluene, -78.degree. C.) followed
by dehydration (TFAA, lutidine). The title compound was obtained by
cyclopropanation of the 4,5-dehydroproline ethyl ester (Et.sub.2Zn,
ClCH.sub.2I, 1,2-dichloroethane, -15.degree. C.). A more detailed
protocol is as follows:
[0203] Synthesis of 4,5-dehydro-L-proline ethyl ester:
L-pyroglutamic acid ethyl ester (200 g, 1.27 mol) was dissolved in
1.2 liters of methylene chloride and treated sequentially with
di-tert-butyldicarbonate (297 g, 1.36 mol) and a catalytic DMAP
(1.55 g, 0.013 mol) at ambient temperature. After 6 h, the mixture
was quenched with saturated brine and the organic phase was dried
(Na.sub.2SO.sub.4) and filtered through a short silica gel column
to give 323 g (100%) of N-Boc-L-pyroglutamic acid ethyl ester.
N-Boc-L-pyroglutamic acid ethyl ester (160 g, 0.62 mol) was
dissolved in 1 liter of toluene, cooled to -78.degree. C. and
treated with lithium triethylborohydride (666 mL of a 1.0 M soln in
THF) and added dropwise over 90 minutes. After 3 h, 2,6-lutidine
(423 mL, 3.73 mol) was added dropwise followed by DMAP (0.2 g,
0.0016 mol). To this mixture was added TFAA (157 g, 0.74 mol) and
the reaction was allowed to come to ambient temperature over 2 h.
The mixture was diluted with EtOAc and water and the organics were
washed with 3 N HCl, water, aqueous bicarbonate and brine and dried
(Na.sub.2SO.sub.4) and filtered through a silica gel plug to give
165 g of the crude 4,5-dehydroproline ethyl ester that was purified
by flash column chromatography on silica gel with 1:5 ethyl
acetate:hexanes to give 120 g, 75% of the olefin.
[0204] Cyclopropanation of 4,5-dehydro-L-proline ethyl ester:
4,5-Dehydro-L-proline ethyl ester (35.0 g, 0.145 mol) was added to
a solution of neat Et.sub.2Zn (35.8 g, 0.209 mol) in 1 liter of
1,2-dichloroethane at -15.degree. C. To this mixture was added a
dropwise addition of ClCH.sub.2I (102 g, 0.58 mol) over 1 h and the
mixture stirred at -15.degree. C. for 18 h. The reaction was
quenched with saturated aqueous bicarbonate and the solvent was
evaporated and the reaction was taken up in EtOAc, washed with
brine and purified by silica gel chromatography using a stepwise
gradient of from 20% EtOAc/hexanes to 50% EtOAc/hexanes to give
17.5 g (50%) of diastereomerically pure step 1 title compound.
[0205] Step 2. 23
[0206] To a stirred solution of Step 1 compound (411 mg, 1.61 mmol)
in CH.sub.2Cl.sub.2 (1.5 mL) at rt was added TFA (1.5 mL). The
reaction mixture was stirred at rt for 2 h and evaporated. The
residue was diluted with CH.sub.2Cl.sub.2 and then evaporated and
re-evaporated three times to give the title compound as a colorless
oil, 433 mg, 100% yield.
[0207] Step 3. 24
[0208] To a stirred solution of
(S)-N-tert-butoxycarbonyl-isoleucine (372.6 mg, 1.61 mmol) and
benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate
(1.25 g, 2.42 mmol) in CH.sub.2Cl.sub.2 (6 mL) under nitrogen at rt
was added 4-methylmorpholine (NMM) (0.36 mL, 3.2 mmol). After 5
min, a solution of Step 2 compound (433 mg, 1.61 mmol) and NMM
(0.27 mL, 2.4 mmol) in CH.sub.2Cl.sub.2 (1 mL) was added. After
addition, the reaction mixture was stirred under nitrogen at room
temperature overnight. The reaction mixture was diluted with
CH.sub.2Cl.sub.2 (40 mL) and washed with 4% KHSO.sub.4 (10 mL),
aqueous NaHCO.sub.3 (10 mL) and brine (10 mL), dried
(Na.sub.2SO.sub.4) and evaporated. Purification by flash
chromatography (1:4 EtOAc/hexane) gave the title compound as a
colorless oil, 530 mg, 89% yield.
[0209] Step 4 25
[0210] To a stirred solution of Step 3 compound (530 mg, 1.44 mmol)
in MeOH (4 mL) and H.sub.2O (4 mL) at rt was added LiOH--H.sub.2O
(91 mg, 2.16 mmol). The reaction mixture was stirred at rt
overnight and evaporated. Water (10 mL) was added to the residue
and extracted with Et.sub.2O (2.times.10 mL). The aqueous layer was
acidified to .about.pH 4 by adding 4% KHSO.sub.4 dropwise. The
milky solution was extracted with EtOAc (15 mL.times.3). Combined
EtOAc layers were washed with brine, dried over Na.sub.2SO.sub.4
and evaporated to give the title compound as a white solid, 440 mg,
90% yield.
[0211] Step 5 26
[0212] To a stirred solution of Step 4 compound (300 mg, 0.88 mmol)
in THF (6 mL) at -15.degree. C. under nitrogen, was added
4-methylmorpholine (0.12 mL, 1.06 mmol) and then isobutyl
chloroformate (0.13 mL, 0.97 mmol) over 2 min. White precipitate
was formed. The reaction mixture was stirred at -15.degree. C.
under nitrogen for 25 min and a solution of NH.sub.3 in dioxane
(8.8 mL, 4.4 mmol) was added. The reaction mixture was stirred at
-15.degree. C. for 30 min, warmed to rt and stirred at rt
overnight. The reaction mixture was quenched by 4% KHSO.sub.4 to
.about.pH 4 and extracted with EtOAc (20 mL.times.3). The extracts
were combined, washed with brine (10 mL) dried (Na.sub.2SO.sub.4)
and evaporated. Purification by flash column chromatography (1:1
EtOAc/hexane) gave the title compound as a white foam, 268 mg, 90%
yield.
[0213] Step 6 27
[0214] To a stirred solution of Step 5 compound (248 mg, 1.38 mmol)
and imidazole (94 mg, 1.38 mmol) in dry pyridine (12 mL) at
-35.degree. C. under nitrogen was added POCl.sub.3 (0.26 mL, 2.76
mmol) dropwise. The reaction mixture was stirred between
-35.degree. C. to -20.degree. C. for 1 h and evaporated.
CH.sub.2Cl.sub.2 (10 mL) was added and white precipitates were
formed. After filtration, the filtrate was concentrated and
purified by flash chromatography (2:5 EtOAc/hexane) to give the
title compound as a colorless oil, 196 mg, 88% yield.
[0215] Step 7 28
[0216] To a stirred solution of Step 6 compound (130 mg, 0.4 mmol)
in CH.sub.2Cl.sub.2 (2 mL) at rt was added TFA (2 mL). The reaction
mixture was stirred at rt for 2 h. The reaction mixture was added
slowly to a pre-cooled slurry of NaHCO.sub.3 (3.8 g) in H.sub.2O (3
mL). The mixture was extracted with CH.sub.2Cl.sub.2 (6
mL.times.5), and the combined CH.sub.2Cl.sub.2 layers were
evaporated and purified by preparative HPLC to give the title
compound as a white powder, 77 mg. 57% yield, mp=141-143.degree. C.
LC/MS gave the correct molecular ion [(M+H).sup.+=222] for the
desired compound.
EXAMPLE 2
[0217] Step 1 29
[0218] Step 1 title compound was synthesized by following the
literature procedure. [Stephen Hanessian, Ulrich Reinhold, Michel
Saulnier, and Stephen Claridge; Bioorganic & Medicinal
Chemistry Letters 8 (1998) 2123-2128.]
[0219] Step 2 30
[0220] The title compound was prepared from Step 1 compound,
employing the same procedure as that described for Example 1, Steps
2-6. LC/MS gave the correct molecular ion [(M+H).sup.+=222] for the
desired compound.
EXAMPLE 3
[0221] Step 1 31
[0222] Step 1 title compound was prepared by following the
literature procedure. [Willy D. Kollmeyer, U.S. Pat. No.
4,183,857.].
[0223] Step 2 32
[0224] To a stirred solution of
(S)-N-tert-butoxycarbonyl-isoleucine (231 mg, 1 mmol) and
benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate
(780 mg, 1.5 mmol) in CH.sub.2Cl.sub.2 (6 mL) under nitrogen at rt
was added 4-methylmorpholine (0.33 mL, 3 mmol). After 5 min, Step 1
compound (120 mg, 1 mmol) was added in one portion. The reaction
mixture was stirred under nitrogen at rt overnight and then diluted
with CH.sub.2Cl.sub.2 (30 mL), washed with 4.1% KHSO.sub.4 (10 mL),
aqueous NaHCO.sub.3 (10 mL), brine (10 mL), dried
(Na.sub.2SO.sub.4) and evaporated. Purification by flash
chromatography on silica gel (2.4.times.20 cm column, 1:3
EtOAc/hexane) gave the title compound as a colorless oil, 290 mg,
90% yield. LC/MS gave the correct molecular ion [(M+H).sup.+=297]
for the desired compound.
[0225] Step 3 33
[0226] The reaction mixture of Step 2 compound (220 mg, 0.74 mmol)
and 4 M HCl in dioxane (1.5 mL, 6 mmol) was stirred at rt for 2 h
and evaporated under reduced pressure. Et.sub.2O was added to the
residue and a precipitate was formed. Et.sub.2O was decanted and
this was done three times. The precipitate was dried in vacuo to
give the title compound as a white powder, 130 mg (76% yield), mp
205-206.degree. C. LC/MS gave the correct molecular ion
[(M+H).sup.+=197] for the desired compound.
EXAMPLES 4-4A
[0227] Step 1 34
[0228] Step 1 title compound, as a 1:1 ratio of enantiomers, was
prepared by following the literature procedure. [Willy D.
Kollmeyer, U.S. Pat. No. 4,183,857.]
[0229] Step 2 35
[0230] A slurry of (S)-N-tert-butoxycarbonyl-isoleucine (92.5 mg,
0.4 mmol), 1-[(3-(dimethyl)amino)propyl]-3-ethylcarbodiimide(77 mg,
0.4 mmol) and HOAT (54.4 mg, 0.4 mmol) in ClCH.sub.2CH.sub.2Cl (0.3
mL) was stirred under nitrogen at rt for 1 h, then Step 1 compound
(22 mg, 0.2 mmol) was added, followed by Et.sub.3N (0.015 mL, 0.1
mmol). The reaction mixture was stirred under nitrogen at rt
overnight and then diluted with CH.sub.2Cl.sub.2 (3 mL), washed
with H.sub.2O (1 mL), aqueous NaHCO.sub.3(1 mL) and brine (1 mL),
dried (Na.sub.2SO.sub.4) and evaporated. Purification by flash
chromatography on silica gel (2.4.times.12 cm column, 2:7
EtOAc/hexane) gave the title compound as a colorless oil, 33 mg,
51% yield. LC/MS gave the correct molecular ion [(M+H).sup.+=322]
for the desired compound.
[0231] Step 3 36
[0232] To a stirred solution of Step 2 compound (30 mg, 0.4 mmol)
in CH.sub.2Cl.sub.2 (0.5 mL) at rt was added TFA (0.5 mL). The
reaction mixture was stirred at rt for 2 h. The reaction mixture
was added slowly to a precooled slurry of NaHCO.sub.3 (0.8 g) in
H.sub.2O (1 mL). The mixture was extracted with CH.sub.2Cl.sub.2 (2
mL.times.5), and combined CH.sub.2Cl.sub.2 layers were evaporated
and purified by preparative HPLC to give the title compounds as a
1:1 ratio of diastereomers, 22 mg, 73% yield. LC/MS gave the
correct molecular ion [(M+H).sup.+=222] for the desired
compounds.
EXAMPLES 5-5A
[0233] 37
[0234] To a solution of Example 4, Step 1 compound (150 mg, 1.39
mmol) in 2-propanol (0.8 mL), was added NaCN (40 mg, 1.0 mmol). The
reaction mixture was heated to reflux for 3 h. After cooling to rt,
the reaction mixture was evaporated and then slurried in Et.sub.2O
(5 mL). After filtration, the filtrate was evaporated to give
Example 4 Step 1 compounds and Example 5 Step 1 compounds (140 mg,
93%) as a 2:1 mixture of diastereomers, each as a racemic
mixture.
[0235] Step 2 38
[0236] A slurry of (S)-N-tert-butoxycarbonyl-isoleucine (595 mg,
2.57 mmol), 1-[(3-(dimethyl)amino)propyl]-3-ethylcarbodiimide(493
mg, 2.57 mmol) and 1-hydroxy-7-azabenzotriazole (350 mg, 2.57 mmol)
in ClCH.sub.2CH.sub.2Cl (2 mL) was stirred under nitrogen at rt for
1 h, then Step 1 compound mixture (139 mg, 1.28 mmol) was added.
The reaction mixture was stirred under nitrogen at rt overnight and
then diluted with CH.sub.2Cl.sub.2 (30 mL), washed with H.sub.2O
(10 mL), saturated aqueous NaHCO.sub.3 (10 mL) and brine (10 mL),
dried (Na.sub.2SO.sub.4) and evaporated. Purification by flash
chromatography on silica gel (2.4.times.20 cm column, 1:3
EtOAc/hexane) gave the Example 4, Step 2 compound (260 mg), and the
title compounds (105 mg) as a ratio of 1:1 diastereomers. LC/MS
gave the correct molecular ion [(M+H).sup.+=322] for the desired
compounds.
[0237] Step 3 39
[0238] To a stirred solution of Step 2 compounds (104 mg, 0.32
mmol) in CH.sub.2Cl.sub.2 (1 mL) at rt was added TFA (1 mL). The
reaction mixture was stirred at rt for 2 h. The reaction mixture
was added slowly to a precooled slurry of NaHCO.sub.3 (2 g) in
H.sub.2O (2 mL). The mixture was extracted with CH.sub.2Cl.sub.2 (4
mL.times.4), and combined CH.sub.2Cl.sub.2 layers were evaporated
and purified by preparative HPLC to give the title compound Example
5 (36 mg) and Example 5A (36 mg). LC/MS gave the correct molecular
ion [(M+H).sup.+=222] for the desired compounds.
EXAMPLE 6
[0239] General Method A:
[0240] Parallel array synthesis methods for preparation of
inhibitors from commercially available amino acids. As shown in
Scheme 3, the ester 11, described in Example 1 Step 1, was
saponified to the acid with LiOH in THF/H.sub.2O and converted to
the amide 12 by treatment with isobutyl chloroformate/NMM followed
by ammonia in dioxane. The Boc protecting group was removed under
acidic conditions using TFA in methylene chloride to give 13. The
TFA salt was coupled to Boc-t-butylglycine using either
EDAC/HOBT/DMF or EDAC/DMAP/CH.sub.2Cl.sub.2 to give 14. The amide
was dehydrated to the nitrile 15 using POCl.sub.3/imidazole in
pyridine at -20.degree. C. and finally deprotected with TFA in
CH.sub.2Cl.sub.2 at ambient temperature to afford the target 16.
40
[0241] Step 1 41
[0242] To a stirred solution of Example 1 Step 1 compound (1.40 g,
5.49 mmol) in 40 mL of a 1:1 methanol:water solution at rt was
added lithium hydroxide (0.20 g, 8.30 mmol). The reaction mixture
was stirred at rt for 18 h and then heated to 50.degree. C. for 2
h. The mixture was diluted with equal volumes of ether and water
(50 mL) and then acidified with KHSO.sub.4 to pH 3. The milky
solution was extracted with ether (3.times.20 mL). The combined
ether layers were dried over Na.sub.2SO.sub.4 and evaporated. The
residue was stripped from toluene (2 X 10 mL) and dried under
reduced pressure to give the title compound as a thick syrup, 1.20
g, 96%.
[0243] Step 2 42
[0244] To a stirred solution of Step 1 compound (1.20 g, 5.28 mmol)
in THF (20 mL) at -15.degree. C. under nitrogen was added
4-methylmorpholine (0.71 mL, 6.50 mmol) and then isobutyl
chloroformate (0.78 mL, 6.00 mmol) over 5 min. The reaction was
stirred at -15.degree. C. for 30 min, cooled to -30.degree. C. and
treated with a solution of NH.sub.3 in dioxane (50 mL, 25 mmol).
The reaction mixture was stirred at -30.degree. C. for 30 min,
warmed to rt and stirred overnight. The reaction mixture was
quenched with citric acid solution (pH 4) and extracted with ether
(3.times.50 mL). The combined organic fractions were washed with
brine, dried over Na.sub.2SO.sub.4 and concentrated. Purification
by flash column chromatography on silica gel with EtOAc gave the
Step 2 compound, 1.00 g, 84%.
[0245] Step 3 43
[0246] To a stirred solution of Step 2 compound (0.90 g, 4.00 mmol)
in CH.sub.2Cl.sub.2 (3 mL) at 0.degree. C. was added TFA (3 mL).
The reaction mixture was stirred at 0.degree. C. for 18 h. The
reaction mixture was concentrated under reduced pressure to produce
title compound in the form of a thick oil, 0.98 g, 100%. The oil
gradually solidified upon prolonged standing.
[0247] Step 4 44
[0248] An oven-dried 15-mL test tube was charged with Step 3
compound (56 mg, 0.22 mmol), N-tert-butoxycarbonyl-(L)-tert-leucine
(53 mg, 0.23 mmol), dimethylaminopyridine (0.11 g, 0.88 mmol), and
CH.sub.2Cl.sub.2 (4 mL). The tube was sealed under nitrogen
atmosphere and treated with
1-[(3-(dimethyl)amino)propyl]-3-ethylcarbodiimide (84 mg, 0.44
mmol). The mixture was placed in a shaker and vortexed overnight.
The product was purified by solid phase extraction using a United
Technology SCX column (2 g of sorbent in a 6 mL column) by loading
the material on a SCX ion exchange column and successively washing
with CH.sub.2Cl.sub.2 (5 mL), 30% methanol in CH.sub.2Cl.sub.2 (5
mL), 50% methanol in CH.sub.2Cl.sub.2 (5 mL) and methanol (10 mL).
The product containing fractions were concentrated under reduced
pressure to give the desired amide. Further purification by reverse
phase preparative column chromatography on a YMC S5 ODS
20.times.250 mm column gave the title compound, 50 mg (68% yield).
Purification conditions: Gradient elution from 30%
methanol/water/0.1 TFA to 90% methanol/water/0.1 TFA over 15 min. 5
min. hold at 90% methanol/water/0.1 TFA. Flow rate: 20 mL/min.
Detection wavelength: 220. Retention Time: 14 min.
[0249] Step 5 45
[0250] An oven-dried 15-mL test tube was charged with Step 4
compound (50 mg, 0.15 mmol), imidazole (31 mg, 0.46 mmol), and
pyridine (1 mL). The tube was sealed under nitrogen atmosphere and
cooled to -30.degree. C. Slow addition of POCl.sub.3 (141 mg, 88
uL, 0.92 mmol) gave after mixing a thick slurry. The tube was mixed
at -30.degree. C. for 3 h and the volatiles evaporated. The product
was purified by solid phase extraction using a United Technology
silica extraction column (2 g of sorbent in a 6 mL column) by
loading the material on a silica column and successively washing
with CH.sub.2Cl.sub.2 (5 mL), 5% methanol in CH.sub.2Cl.sub.2 (5
mL), 7% methanol in CH.sub.2Cl.sub.2 (5 mL) and 12% methanol in
CH.sub.2Cl.sub.2 (10 mL). The product containing fractions were
pooled and concentrated under reduced pressure to give the title
compound, 46 mg, 96%.
[0251] Step 6 46
[0252] An oven-dried 15-mL test tube was charged with Step 5
compound (0.45 mg, 0.14 mmol), CH.sub.2Cl.sub.2 (1 mL), and TFA (1
mL). The reaction mixture was vortexed for 40 min at rt, diluted
with toluene (4 mL) and concentrated under reduced pressure to a
thick oil. The product was purified by reverse phase preparative
column chromatography on a YMC S5 ODS 20.times.250 mm column to
give the Example 6 compound, 14 mg, 35%. Purification conditions:
gradient elution from 10% methanol/water/0.1 TFA to 90%
methanol/water/0.1 TFA over 18 min; 5 min hold at 90%
methanol/water/0.1 TFA. Flow rate: 20 mL/min. Detection wavelength:
220. Retention Time: 10 min.
[0253] Examples 7-27 were prepared from amino acids available from
commercial sources according to the procedure in Example 6.
1TABLE 1 47 Example R [M + H] 7 48 302 8 49 295 9 50 240 10 51 222
11 52 222 12 53 222 13 54 208 14 55 270 15 56 222 16 57 206 17 58
256 18 59 268 19 60 220 20 61 220 21 62 210 22 63 262 23 64 242 24
65 210 25 66 281 26 67 281 27 68 272
EXAMPLE 27
[0254] Step 1 69
[0255] (2S,4S,5S)-4,5-methano-L-proline carboxylamide, TFA salt (53
mg, 0.22 mmol) was coupled to N-Boc-L-Tyrosine-benzyl ether (82 mg,
0.22 mmol) using PyBop (172 mg, 0.33 mmol) and N-methylmorpholine
(67 mg, 0.66 mmol) in 4 mL CH.sub.2Cl.sub.2. The reaction stirred
for 16 h, was taken up in EtOAc, washed with H.sub.2O, 1N aqueous
HCl, brine, then evaporated and purified by silica gel flash
chromatography to give the coupled product (FAB MH+ 480).
[0256] Step 2 70
[0257] The Step 1 amide was dehydrated to the nitrile using the
general method C (which follows Example 29) (FAB MH+ 462).
[0258] Step 3 71
[0259] The Step 2 benzyl ether was cleaved by catalytic
hydrogenolysis using 10% palladium on carbon and 1 atmosphere
hydrogen gas in MeOH at rt for 1.5 h. The reaction was filtered
through celite and concentrated to an oil and taken on without
further purification (FAB MH+ 372).
[0260] Step 4 72
[0261] Step 3
N-[N-Boc-L-Tyrosine-]-(2S,4S,5S)-2-cyano-4,5-methano-L-proly-
lamide was dissolved in CH.sub.2Cl.sub.2 and TFA was added at rt.
The reaction stirred for 1 h and was evaporated and purified by
preparative HPLC as described in general method B (set out
following Example 29) to afford the title compound (FAB MH+
272).
EXAMPLE 28
[0262] 73
[0263] The title compound was prepared by coupling
(2S,4S,5S)-4,5-methano-- L-proline carboxylamide, TFA salt
described in Example 6 Step 3 compound with
N-(tert-butyloxy-carbonylhydroxyvaline. After hydroxyl protection
with triethylsilyl chloride and dehydration of the amide with
POCl.sub.3/imidazole in pyridine and deprotection (N-terminal
nitrogen and valine hydroxyl) with TFA using general method C (FAB
MH+ 224), the title compound was obtained.
EXAMPLE 29
[0264] Step 1 74
[0265] N-Boc-L-homoserine (1.20 g, 5.47 mmol) upon treatment with
tert-butyldimethylsilyl chloride (1.67 g, 11.04 mmol) and imidazole
(938 mg, 13.8 mmol) in THF (17 mL) was stirred as thick slurry for
48 h under N.sub.2. The solvent was evaporated, and the crude
material was dissolved in MeOH (10 mL). The resulting solution was
stirred at rt for 2 h. The solvent was evaporated, and the crude
material was diluted with CH.sub.2Cl.sub.2 (50 mL) and treated with
0.1N HCl (2.times.10 mL). The CH.sub.2Cl.sub.2layer was washed with
brine and dried over MgSO.sub.4. Removal of the volatiles gave
title compound as an oil (1.8 g), which was used without further
purification (LC/Mass, +ion): 334 (M+H).
[0266] Step 2 75
[0267] To a stirred solution of Step 1 compound (333 mg, 1.0 mmol)
in 6 mL of CH.sub.2Cl.sub.2 was added
1-[3-(dimethylamino)propyl]-3-ethylcarbodii- mide hydrochloride
(256 mg, 1.32 mmol) The solution was then stirred at rt for 30 min,
followed by addition with Example 6 Step 3 amine TFA salt (160 mg,
0.66 mmol) and 4-(dimethylamino)pyridine (244 mg, 2.0 mmol). The
solution was then stirred at rt overnight. The mixture was diluted
with CH.sub.2Cl.sub.2 (5 mL) and washed sequentially with H.sub.2O,
10% citric acid, brine, then dried over Na.sub.2SO.sub.4 and
evaporated to give the title compound (350 mg) which was used
without further purification (LC/Mass, +ion): 442 (M+H).
[0268] Step 3 76
[0269] An oven-dried 10-mL round bottomed flask was charged with
Step 2 compound (350 mg, 0.79 mmol), imidazole (108 mg, 1.58 mmol),
pyridine (3 mL). The flask under argon was cooled to -30.degree. C.
Slow addition of POCl.sub.3 (0.30 mL, 3.16 mmol) gave after mixing
a thick slurry. The slurry was mixed at -30.degree. C. for 3 h and
the volatiles evaporated. Dichloromethane (5 mL) was then added and
the insoluble solid was removed by filtration. The organic layer
was washed with H.sub.2O, 10% citric acid, brine and dried over
Na.sub.2SO.sub.4. Removal of solvent gave crude desired nitrile
(330 mg) (LC/Mass, +ion): 424 (M+H).
[0270] Step 4 77
[0271] Trifluoroacetic acid (3.3 mL) was added to a stirred
solution of Step 3 compound (330 mg, 0.58 mmol) in 3.3 mL
CH.sub.2Cl.sub.2. The solution was then stirred at rt for 30 min, a
few drops of water were added and the mixture mixture stirred for
0.5 h. The mixture was diluted with CH.sub.2Cl.sub.2 (5 mL) and
concentrated under reduced pressure to a thick oil. The product was
purified by reverse phase preparative column chromatography on a
YMC 5 ODS 20.times.100 mm column to give the title compound, 59 mg,
17%. Purification conditions: gradient elution from 10%
methanol/water/0.1 TFA to 90% methanol/water/0.1 TFA over 15 min; 5
min hold at 90% methanol/water/0.1 TFA. Flow rate: 20 mL/min.
Detection wavelength: 220. Retention Time 10 Min. (LC/Mass, +ion):
210 (M+H).
[0272] General Method B:
[0273] Claisen rearrangement sequence to Boc-protected amino acids.
78
[0274] General method B affords the quaternary Boc-protected amino
acids. Examples 30-47 contain the vinyl sidechain by coupling amino
acids of which Scheme 4, compound 20 is representative.
Cyclopentanone was olefinated under Horner-Emmons conditions to
afford 17 which was reduced to the allylic alcohol 18 using DIBAL-H
in toluene -78.degree. C. to rt. Allylic alcohol 18 was esterified
with N-Boc glycine using DCC/DMAP in CH.sub.2Cl.sub.2 to give 19.
Glycine ester 19 was subjected to a Lewis acid mediated Claisen
rearrangement by complexation with anhydrous zinc chloride and
deprotonation at -78.degree. C. with lithium diisopropylamide
followed by warming to ambient temperature to afford 20. 79
[0275] Step 1
[0276] Cyclopentylideneacetic Acid Ethyl Ester.
[0277] To a flame-dried 500-mL round-bottomed flask containing NaH
(5.10 g of a 60% dispersion in mineral oil, 128 mmol, 1.10 equiv)
in 120 mL anhydrous THF at 0C under argon was added
triethylphosphonoacetate (25.6 mL, 128 mmol, 1.10 equiv) dropwise
through an addition funnel. The mixture was allowed to warm to rt,
stirring for an additional 1 h. A solution of cyclopentanone (10.3
mL, 116 mmol) in 10 mL anhydrous THF was added dropwise over 20 min
through an addition funnel, and the mixture was allowed to stir at
rt for 2.5 h. Ether (200 mL) and water (100 mL) were then added,
and the layers were separated. The organic phase was washed
successively with water (100 mL) and brine (100 mL), dried
(Na.sub.2SO.sub.4), and concentrated under reduced pressure, giving
17.5 g (98%) of the desired ester as a colorless oil.
[0278] Step 2
[0279] 2-Cyclopentylideneethanol.
[0280] To a flame-dried 500-mL round-bottomed flask containing
cyclopentylideneacetic acid ethyl ester (17.5 g, 113 mmol) in 100
mL anhydrous toluene at -78.degree. C. under argon was added
DIBAL-H (189 mL of a 1.5 M solution in toluene, 284 mmol, 2.50
equiv) dropwise over a 30 min period through an addition funnel,
and the mixture was then allowed to warm to rt, stirring for 18 h.
The reaction mixture was then recooled to -78.degree. C., and
quenched by the careful addition of 30 mL anhydrous MeOH. Upon
warming to rt, 1 N Rochelle's salt (100 mL) was added, and the
mixture was stirred 90 min. The biphasic reaction mixture was then
diluted with Et.sub.2O (200 mL) in a separatory funnel, and the
layers were separated. The organic layer was then washed with brine
(100 mL), dried (Na.sub.2SO.sub.4), and concentrated under reduced
pressure. Purification by flash column chromatography (silica gel,
CH.sub.2Cl.sub.2/EtOAc, 10:1) gave 11.6 g (92%) of the desired
allylic alcohol as a colorless oil.
[0281] Step 3
[0282] (2-Cyclopentylideneethyl)-N-(tert-Butyloxycarbonyl)
glycinate. 80
[0283] To a flame-dried 500-mL round-bottomed flask containing
N-(tert-butyloxycarbonyl)glycine (13.45 g, 76.75 mmol) in 100 mL
CH.sub.2Cl.sub.2 at rt was added Step 2 compound (8.61 g, 76.75
mmol, 1.00 equiv) in 20 mL CH.sub.2Cl.sub.2, followed by
dicyclohexylcarbodiimide (16.63 g, mmol, 1.05 equiv) in 80 mL
CH.sub.2Cl.sub.2. To this reaction mixture was then added
4-dimethylaminopyridine (0.94 mg, mmol, 0.10 equiv), and the
mixture was allowed to stir overnight. The reaction mixture was
then filtered through a medium sintered-glass funnel, rinsing with
100 mL CH.sub.2Cl.sub.2, and concentrated under reduced pressure.
The crude product was then purified by flash chromatography (silica
gel, hexanes/EtOAc, 20:1 to 1:1 gradient) to give 19.43 g (94%) of
the desired glycinyl ester as a colorless oil.
[0284] Step 4
[0285] N-(tert-Butyloxycarbonyl)(1'vinylcyclopentyl)-glycine 81
[0286] A flame-dried 500-mL round-bottomed flask under argon was
charged with ZnCl.sub.2 (11.8 g, mmol, 1.20 equiv) and 20 mL
toluene. The mixture was heated under vacuum with vigorous stirring
to azeotrope off any traces of moisture with the distilling
toluene, repeating this process (2.times.). The flask was then
cooled to rt under argon, (2-cyclopentylideneethyl)
N-(tert-butyloxycarbonyl)glycinate (19.36 g, 71.88 mmol) was added
via cannula as a solution in 180 mL THF, and the mixture was then
cooled to -78.degree. C. In a separate flame-dried 200-mL
round-bottomed flask containing diisopropylamine (26.3 mL, mmol,
2.60 equiv) in 90 mL THF at -78.degree. C. was added n-butyllithium
(71.89 mL of a 2.5 M solution in hexanes, mmol, 2.5 equiv), and the
mixture was allowed to warm to 0.degree. C. for 30 min before
recooling to -78.degree. C. The lithium diisopropylamine thus
generated was then added via cannula to the ZnCl.sub.2 ester
mixture dropwise at a steady rate over 40 min, and the resultant
reaction mixture was allowed to slowly warm to rt and stir
overnight. The yellow reaction mixture was then poured into a
separatory funnel, diluted with 300 mL Et.sub.2O, and the resultant
organic solution was washed successively with 300 mL 1N HCl and 300
mL brine, dried (Na.sub.2SO.sub.4), and concentrated under reduced
pressure. Purification by flash chromatography (silica gel, 3% MeOH
in CH.sub.2Cl.sub.2 with 0.5% HOAc) gave 17.8 g (92%) of the
desired amino acid product as a white solid. (FAB MH+ 270).
EXAMPLE 30
[0287] General Method C:
[0288] Peptide coupling to 4,5-methanoprolinamide, amide
dehydration and final deprotection. 82
[0289] The TFA salt of amide 13 was coupled to a variety of racemic
quaternary protected amino acids using HOBT/EDC in DMF at rt to
give a D/L mixture of diastereomers at the N-terminal amino acid.
The desired L diastereomer was chromatographically isolated either
as the amide 21 or as the nitrile 22. Nitrile 22 was obtained by
treatment of the amide with POCl.sub.3/imidazole in pyridine at
-20.degree. C. The final target 23 was obtained by deprotection
under acidic conditions using TFA in CH.sub.2Cl.sub.2. 83
[0290] Step 1 84
[0291] Example 6 Step 3 compound (877 mg, 3.65 mmol) and N-Boc
cyclopentylvinylamino acid, described in Step 4 of general method B
(1.13 g, 4.20 mmol) were dissolved in 20 mL anhydrous DMF, cooled
to 0.degree. C. and to this mixture was added EDAC (1.62 g, 8.4
mmol), HOBT hydrate (2.54 g, 12.6 mmol, and TEA (1.27 g, 12.6 mmol)
and the reaction was allowed to warm to rt and stirred for 24 h.
The reaction mixture was taken up in EtOAc (100 mL), washed with
H.sub.2O (3.times.20 mL), dried (Na.sub.2SO.sub.4), and purified by
silica gel flash column chromatography (100% EtOAc) to give 1.38 g
(86%) of Step 1 compound (MH+, 378).
[0292] Step 2 85
[0293] Step 1 compound (1.38 g, 3.65 mmol) and imidazole (497 mg,
7.30 mmol) were dried by toluene azeotrope (5 mL.times.2),
dissolved in 10 mL anhydrous pyridine, cooled to -30.degree. C.
under nitrogen gas and POCl.sub.3 (2.23 g, 14.60 mmol) was added by
syringe. The reaction was complete after 1 h and was evaporated to
dryness and the remainder purified by two sequential flash column
chromatographies over silica gel. The first column (100% EtOAc) was
used to isolate the mixture of diastereomers (1.15 g, 88%) from the
by-products of the reaction. The second column (gradient of 25%
EtOAC/hexanes to 50% EtOAc/hexanes) was run to resolve the mixture
of diastereomers and provided 504 mg of the desired Step 2 nitrile
(MH+360).
[0294] Step 3 86
[0295] Step 2 compound (32 mg, 0.09 mmol) was dissolved in 1 mL of
CH.sub.2Cl.sub.2 and 1 mL of TFA was added and the reaction stirred
for 30 min at rt and was evaporated to dryness. The product was
purified by reverse phase preparative column chromatography on a
YMC S5 ODS 20.times.250 mm column to give 12 mg of the TFA salt
(lyophilized from water or isolated after evaporation of eluent and
trituration with ether) the title compound. Purification
conditions: gradient elution from 10% methanol/water/0.1 TFA to 90%
methanol/water/0.1 TFA over 18 min; 5 min. hold at 90%
methanol/water/0.1 trifluoroacetic acid. Flow rate: 20 mL/min.
Detection wavelength: 220.
[0296] Examples 30-39 were prepared by the methods outlined in
General Method B and General Method C starting from cyclopentanone,
cyclobutanone, cyclohexanone, cycloheptanone, cyclooctanone,
cis-3,4-dimethylcyclopentanone, and 4-pyranone,
cyclopropaneethylhemiacet- al, acetone, and 3-pentanone
respectively.
2TABLE 2 87 MS Example R [M + H] 30 88 260 31 89 246 32 90 274 33
91 288 34 92 302 35 93 288 36 94 276 37* 95 232 38 96 234 39 97 262
*Step 3 compound was prepared by the method described in
Tetrahedron Letters 1986, 1281-1284.
EXAMPLE 40
[0297] Step 1 98
[0298] Step 1 compound was prepared employing general method B
starting from cyclopentanone and 2-fluoro-triethylphosphonoacetate
instead of triethylphosphonoacetate.
[0299] Step 2 99
[0300] Title compound was prepared by the peptide coupling of Step
1 acid followed by dehydration and final deprotection as described
in general method C [MS (M+H) 278].
EXAMPLE 41
[0301] Step 1 100
[0302] Step 1 compound was prepared employing general method B
starting from cyclobutanone and 2-fluoro-triethylphosphonoacetate
instead of triethylphosphonoacetate.
[0303] Step 2 101
[0304] Title compound was prepared by the peptide coupling of Step
1 acid followed by dehydration and final deprotection as described
in general method C. MS (M+H) 264.
EXAMPLE 42
[0305] Step 1 102
[0306] Step 1 compound was prepared employing general method B
starting from cyclopentanone and triethylphosphonopropionate
instead of triethylphosphonoacetate.
[0307] Step 2 103
[0308] Title compound was prepared by the peptide coupling of Step
1 acid followed by dehydration and final deprotection as described
in general method C. MS (M+H) 274
EXAMPLE 43
[0309] Step 1 104
[0310] Step 1 compound was prepared employing general method B
starting from cyclobutanone and triethylphosphonopropionate instead
of triethylphosphonoacetate.
[0311] Step 2 105
[0312] Title compound was prepared by the peptide coupling of Step
1 acid followed by dehydration and final deprotection as described
in general method C. MS (M+H) 260.
EXAMPLE 44
[0313] General Method D:
[0314] Oxidative cleavage of vinyl substituent by ozonolysis. The
protected cyclopentylvinyl nitrile 22 was treated with ozone for
6-8 min and subjected to a reductive quench with sodium borohydride
to furnish the hydroxymethyl analog 24 directly. This compound was
deprotected under acidic conditions with TFA in CH.sub.2Cl.sub.2 at
0.degree. C. to give the target compound 25. 106
[0315] Step 1 107
[0316] Cyclopentylvinyl compound prepared in Step 2 of general
method C (1.28 g, 3.60 mmol) was dissolved in 56 mL of a 2:5
mixture of CH.sub.2Cl.sub.2:methanol, cooled to -78.degree. C. and
was treated with a stream of ozone until the reaction mixture took
on a blue color, at which time, NaBH.sub.4 (566 mg, 15.0 mmol, 4.2
equiv) was added and the reaction was warmed to 0.degree. C. After
30 min, the reaction was quenched with 2 mL saturated aqueous
NaHCO.sub.3 and then warmed to rt. The reaction mixture was
evaporated to dryness and taken up in EtOAc. A small amount of
water was added to dissolve the inorganics and the layers
separated. The EtOAc layer was dried (Na.sub.2SO.sub.4), filtered
and evaporated to an oil that was purified by flash column
chromatography on silica gel with EtOAc to give 922 mg (71%) of
Step 1 compound. MS(M+H)364.
[0317] Step 2 108
[0318] Step 1 compound (900 mg, 2.48 mmol) was dissolved in 60 mL
of CH.sub.2Cl.sub.2, cooled to 0.degree. C. and treated with 20 mL
of freshly distilled TFA. The reaction was complete in 80 min and
the mixture was evaporated to dryness and purified by preparative
HPLC (YMC S5 ODS 30.times.100 mm, 18 minute gradient 80% Solv
A:Solv B to 100% Solv B, Solvent A=10% MeOH-90%H.sub.2O-0.1% TFA,
Solvent B=90% MeOH-10% H.sub.2O-0.1% TFA, collected product from
5.1-6.5 min) to give, after lyophillization from water, 660 mg
(71%) of title compound, TFA salt as a white lyophillate.
(MH+264).
EXAMPLE 45
[0319] General Method E:
[0320] Oxidative cleavage of vinyl substituent by osmium
tetroxide-sodium periodate followed by sodium borohydride reduction
to alcohol. The cyclobutylolefin 26 was treated with osmium
tetroxide and sodium periodate in THF:water, 1:1, and the
intermediate aldehyde was isolated crude and immediately reduced
with sodium borohydride to give 27 in 56% yield. Standard
deprotection conditions using TFA afforded the target compound 28.
109 110
[0321] N-Boc protected cyclobutylvinyl compound (Example 31,
prepared by general method C) (0.16 g, 0.46 mmol) was dissolved in
10 mL of a 1:1 mixture of THF:water and treated with OsO.sub.4 (12
mg, catalyst) and NaIO.sub.4 (0.59 g, 2.76 mmol, 6 equiv). After 2
h, the reaction mixture was diluted with 50 mL of ether and 10 mL
of water. The layers were equilibrated and the organic fraction was
washed one time with NaHCO.sub.3 solution, dried over MgSO.sub.4
and concentrated to give a dark oil. The oil was diluted with 10 mL
of methanol and treated with NaBH.sub.4 (0.08 g, 2.0 mmol). The
mixture turned very dark and after 30 min was diluted with ether
and the reaction was quenched with aqueous NaHCO.sub.3 solution.
The mixture was equilibrated and layers separated. The organic
fraction was washed with solutions of NaHCO.sub.3 and 0.1 M HCl.
The organics were dried (MgSO.sub.4) and concentrated to give 90 mg
(56%) of the Step 1 compound as a dark oil.
[0322] Step 2 111
[0323] Step 1 compound (90 mg, 0.26 mmol) was dissolved in 3 mL of
CH.sub.2Cl.sub.2, cooled to 0.degree. C. and treated with 3 mL of
freshly distilled TFA. The reaction was complete in 80 min and
evaporated to dryness and purified by preparative HPLC (YMC S5 ODS
30.times.100 mm, 10 minute gradient 100%A to 100%, Solvent A=10%
MeOH-90%H.sub.2O-0.1% TFA, Solvent B=90% MeOH-10% H.sub.2O-0.1%
TFA, to give, after removal of water, 50 mg (60%) of title
compound. (MH+250).
3TABLE 3 112 Method of Example R Preparation [M + H] 44 113
Ozonolysis/ borohydride 264 45 114 Osmium/periodate/ borohydride
250 46 115 Ozonolysis/ borohydride 278 47 116 Osmium/periodate/
borohydride 292 48 117 Ozonolysis/ borohydride 292
EXAMPLE 49
[0324] Step 1 118
[0325] Part A.
[0326] A 50-mL flask was charged with
dihydro-4,4-dimethyl-2,3-furandione (5.0 g, 39.0 mmol), acetic acid
(10 mL), sodium acetate (3.82 g, 39.0 mmol) and hydroxylamine
hydrochloride (2.71 g, 39.0 mmol). The reaction mixture was stirred
for 2 h at rt and concentrated under reduced pressure to remove
most of the acetic acid. The remainder was poured into water (100
mL) and the aqueous phase extracted with EtOAc (3.times.40 mL). The
organics were dried over Na.sub.2SO.sub.4 and concentrated to a
colorless oil which solidified on standing.
[0327] Part B.
[0328] A 200-mL round bottomed flask was charged with Part A solid
(@ 39 mmol) and diluted with 80 mL of ethanol and 39 mL of 2N HCl
(78 mmol). The mixture was treated with 1.0 g of 5% Pd/carbon and
the mixture degassed. The flask was placed under an atmosphere of
H.sub.2 for 8 h. The mixture was filtered through celite and the
filtrate concentrated to an off white solid.
[0329] Part C.
[0330] A 250-mL round bottomed flask was charged with Part B solid
and diluted with THF (50 mL) and water (15 mL). The mixture was
treated with di-tert-butyldicarbonate (12.7 g, 117 mmol) and sodium
bicarbonate (10.0 g, 117 mmol). After 4 h of stirring the mixture
was diluted with 50 mL of ether and 50 mL of water. The layers were
separated and the organic fraction dried over MgSO.sub.4 and
concentrated. The residue was purified by flash column
chromatography on silica gel with 30% EtOAc in hexanes to give 2.00
g (22% overall) of Step 1 compound as a white solid.
[0331] Step 2 119
[0332] To a stirred solution of Step 1 compound (1.00 g, 3.80 mmol)
in THF (20 mL) at rt under nitrogen was added LiOH hydrate (0.16 g,
3.80 mmol) and then water (5 mL). The reaction was stirred at
40.degree. C. for 0.5 h and then cooled to rt. The mixture was
concentrated to dryness and the remainder was stripped from THF
(2.times.), toluene (2.times.) and THF (1.times.). The remaining
glass was diluted with 5 mL of THF and treated with imidazole (0.63
g, 9.19 mmol) followed by t-butyl-dimethylsilyl chloride (1.26 g,
8.36 mmol). The reaction was stirred overnight and quenched with 10
mL of methanol. After 1 h of stirring the mixture was concentrated.
An additional portion of methanol was added and the mixture
concentrated. The oil was diluted with ether and 0.1 N HCl (pH 2).
The layers were equilibrated and aqueous drawn off. The organic
fraction was dried over MgSO.sub.4 and concentrated to give 1.25 g
(83%) of Step 2 compound as a colorless glass.
[0333] Step 3 120
[0334] The Title compound was prepared by the peptide coupling of
Step 2 carboxylic acid with Example 6 Step 3 amine, followed by
dehydration and deprotection as outlined in General Method C. MS
(M+H) 238.
[0335] General Method F:
[0336] Catalytic Hydrogenation of vinyl substituent. As shown in
Scheme 8, the protected vinyl substituted amino acid 20 was
transformed to the corresponding saturated analog 29 by catalytic
hydrogenation using 10% Pd/C and hydrogen at atmospheric pressure.
121
[0337] Step 1.
[0338] The N-(tert-Butyloxycarbonyl)(1'vinylcyclopentyl)glycine
(2.23 g, 8.30 mmol) was dissolved in 50 mL MeOH and placed in a
hydrogenation vessel purged with argon. To this mixture was added
10% Pd--C (224 mg, 10% w/w) and the reaction stirred under 1 atm
H.sub.2 at rt for 12 h. The reaction was filtered through celite
and concentrated and purified by flash column chromatography on
silica gel with 1:9 methanol:CH.sub.2Cl.sub.2 to give the Step 1
compound as a glass. (FAB MH+ 272)
[0339] Examples 50-56 were prepared by the peptide coupling of
amino acids (where the vinyl substituent has been hydrogenated
according to general method F) followed by dehydration and
deprotection as described in general method C.
4TABLE 4 122 MS Example R1, R2 [M + H] 50 Cyclopentyl 262 51
cyclobutyl 248 52 cycloheptyl 290 53 4-pyranyl 278 54 methyl, 236
methyl 55 ethyl, ethyl 264 56 methyl, ethyl 250
EXAMPLE 57
[0340] 123
[0341] The title compound in Example 57 was prepared by the peptide
coupling of the isopropyl cyclobutane amino acid
[0342] (where the olefin substituent has been hydrogenated
according to general method F) followed by dehydration and
deprotection as described in general method C.
EXAMPLE 58
[0343] 124
[0344] The title compound in Example 58 was prepared by the peptide
coupling of the isopropyl cyclopentane amino acid (where the olefin
substituent has been hydrogenated according to general method F)
followed by dehydration and deprotection as described in general
method C. MS (M+H) 276
[0345] General Method G:
[0346] L-Amino acids synthesized by Asymmetric Strecker Reaction.
Commercially available adamantyl carboxylic acid was esterified
either in MeOH with HCl at reflux or using
trimethylsilyldiazomethane in Et.sub.2O/methanol to give 30. The
ester was reduced to the alcohol 31 with LAH in THF and then
subjected to a Swern oxidation to give aldehyde 32. Aldehyde 32 was
transformed to 33 under asymmetric Strecker conditions with KCN,
NaHSO.sub.3 and R-(-)-2-phenylglycinol. The nitrile of 33 was
hydrolyzed under strongly acidic conditions using 12M HCl in HOAc
to give 34. The chiral auxiliary was removed by catalytic reduction
using Pearlman's catalyst in acidic methanol under 50 psi hydrogen
to give 35 and the resulting amino group was protected as the
t-butylcarbamate to give 36. 125
[0347] Step 1 126
[0348] Adamantane-1-carboxylic acid (10.0 g, 55 mmol, 1 equiv) was
dissolved in a mixture of Et.sub.2O (160 mL) and MeOH (40 mL), and
was treated with trimethylsilyl diazomethane (2.0 M in hexane, 30
mL, 60 mmol, 1.1 equiv) and stirred at rt for 3 h. The volatiles
were then removed by rotary evaporation and the product purified by
flash column chromatography on silica gel (5.times.15 cm) with 40%
CH.sub.2Cl.sub.2/hexanes to give the product as a white crystalline
solid (10.7 g, 100%).
[0349] Step 2 127
[0350] Step 1 compound (10.7 g, 0.055 mmol, 1 equiv) was dissolved
in anhydrous THF (150 mL) under argon and was treated with a
solution of LiAlH.sub.4 (1 M in THF, 69 mL, 69 mmol, 1.25 equiv).
After stirring at rt for 1.5 h, the reaction was cooled to
0.degree. C. and quenched sequentially with H.sub.2O (5.1 mL), 15%
aq NaOH (5.1 mL), and H.sub.2O (10.2 mL). After stirring at rt for
15 min, the slurry was vacuum filtered, and the solids washed with
EtOAc (2.times.100 mL). The filtrate was concentrated by rotary
evaporation and the resulting solid purified by flash column
chromatography on silica gel (5.times.15 cm) with 10%
EtOAc/CH.sub.2Cl.sub.2. This afforded the Step 2 product as a white
solid (8.74 g, 96%).
[0351] Step 3 128
[0352] An oven-dried 3-neck flask equipped with 125-mL addition
funnel was charged with anhydrous CH.sub.2Cl.sub.2 (150 mL) and
anhydrous DMSO (10.3 mL, 0.145 mol, 2.5 equiv) under argon
atmosphere and cooled to -78.degree. C. Slow dropwise addition of
oxalyl chloride (6.7 mL, 0.0768 mol, 1.32 equiv) followed by
stirring for 15 min provided an activated DMSO adduct. This was
treated with a solution of Step 2 compound (9.67 g, 58.2 mmol, 1
equiv) in dry CH.sub.2Cl.sub.2 (75 mL) and the reaction allowed to
stir for 1 h. The resulting white mixture was then treated dropwise
with triethylamine (40.5 mL, 0.291 mol, 5 equiv). After 30 min, the
cooling bath was removed, and the reaction quenched sequentially
with cold 20% aq KH.sub.2PO.sub.4 (25 mL) and cold H.sub.2O (150
mL). After stirring at rt for 15 min the mixture was diluted with
Et.sub.2O (400 mL)and the layers were separated. The organics were
washed organic with cold 10% aq KH.sub.2PO.sub.4 (3.times.150 mL)
and satd aq NaCl (100 mL). The organics were dried
(Na.sub.2SO.sub.4), filtered and concentrated. The residue was
purified by flash column chromatography on silica gel (5.times.10
cm) with CH.sub.2Cl.sub.2 to give the Step 3 compound as a white
solid (9.40 g, 98%).
[0353] Step 4 129
[0354] Step 3 compound (9.40 g, 57 mmol, 1 equiv) was suspended in
H.sub.2O (145 mL) and cooled to 0.degree. C. The mixture was
treated with NaHSO.sub.3 (5.95 g, 57 mmol, 1 equiv), KCN (4.0 g, 59
mmol, 1.04 equiv), and a solution of (R)-(-)-phenylglycinol (8.01
g, 57 mmol, 1 equiv) in MeOH (55 mL). The resulting mixture was
stirred at rt for 2 h, then refluxed for 16 h. The mixture was
cooled to rt, and 200 mL of EtOAc added. After mixing for 15 min
the layers were separated. The aqueous fraction was extracted with
EtOAc. The combined EtOAc extracts were washed with brine (50 mL),
dried over anhydrous Na.sub.2SO.sub.4, filtered and the filtrate
concentrated. The product was purified by flash column
chromatography on silica gel (6.4.times.20 cm) with 20%
EtOAc/hexanes to give the desired (R,S) product as a white solid
(11.6 g, 37.4 mmol, 65%): MS m/e 311 (M+H).sup.+.
[0355] Step 5 130
[0356] The Step 4 nitrile (5.65 g, 18 mmol) was heated in conc. HCl
(120 mL) and HOAC (30 mL) at 80.degree. C. for 18 h, at which time
the reaction was cooled in an ice bath. Vacuum filtration of the
resulting precipitate afforded the desired product as a white solid
(5.21 g, 14 mmol, 78%). MS m/e 330 (m+H).sup.+.
[0357] Step 6 131
[0358] The Step 6 compound (5.21 g, 14 mmol) was dissolved in MeOH
(50 mL) and HOAc (10 mL), and hydrogenated with H.sub.2 (50 psi)
and Pearlman's catalyst (20% Pd(OH).sub.2, 1.04 g, 20% w/w) for 18
h. The reaction was filtered through a PTFE membrane filter and the
catalyst washed with MeOH (3.times.25 mL). The filtrate was
concentrated by rotary evaporation to afford a white solid. The
product was used in Step 7 without further purification.
[0359] Step 7 132
[0360] The crude Step 6 compound (@14 mmol) was dissolved in
anhydrous DMF (50 mL) under argon and treated with K.sub.2CO.sub.3
(5.90 g, 42 mmol, 3 equiv) and di-tert-butyldicarbonate (3.14 g, 14
mmol, 1 equiv) under argon at rt. After 19 h, the DMF was removed
by rotary evaporation (pump) and the residue dried further under
reduced pressure. The residue was mixed with H.sub.2O (100 mL) and
Et.sub.2O (100 mL), the layers separated, and the alkaline aqueous
with Et.sub.2O (2.times.100 mL) to remove the by-product from the
hydrogenolysis step. The aqueous was cooled to 0.degree. C.,
diluted with EtOAc (200 mL), and stirred vigorously while carefully
acidifying the aqueous to pH 3 with 1N aq HCl. The layers separated
and the aqueous extracted with EtOAc (100 mL). The combined EtOAc
extracts were washed with brine (50 mL), dried (Na.sub.2SO.sub.4),
filtered and the filtrate concentrated by rotary evaporation. The
residue was purified by Sio.sub.2 flash column (5.times.12 cm) with
5% MeOH/CH.sub.2Cl.sub.2+0.5% HOAc. The product was chased with
hexanes to afford the product as a white foam (4.07 g, 13 mmol,
92%): MS m/e 310 (m+H).sup.+.
EXAMPLE 59
[0361] 133
[0362] The title compound in Example 59 was prepared by the peptide
coupling of the Step 7 compound in general method G followed by
dehydration and deprotection as described in general method C.MS
m/e 300 (m+H).sup.+.
EXAMPLE 60
[0363] Step 1 134
[0364] A solution of KMnO.sub.4 (337 mg, 2.13 mmol, 1.1 equiv) in
2% aq KOH (6 mL) was heated to 60.degree. C. and Step 7 compound in
general method G (600 mg, 1.94 mmol, 1 equiv) was added in
portions, and heating increased to 90.degree. C. After 1.5 h, the
reaction was cooled to 0.degree. C., EtOAc (50 mL) was added, and
the mixture was carefully acidified to pH 3 with 1N HCl. The layers
were separated and the aqueous was extracted with EtOAc (50 mL).
The combined organic extracts were washed with brine, dried over
Na.sub.2SO.sub.4, filtered and concentrated. The residue was
purified by flash column chromatography on silica gel (3.8.times.15
cm) with 2% (200 mL), 3% (200 mL), 4% (200 mL), and 5% (500 mL)
MeOH/CH.sub.2Cl.sub.2+0.5% HOAc. After isolation of the product,
the material was chased with hexanes to afford a white solid (324
mg, 51%): MS m/e 326 (m+H).sup.+.
[0365] Step 2 135
[0366] The Step 1 compound (404 mg, 1.24 mmol, 1 equiv) was
dissolved in anhydrous DMF (10 mL) under argon and cooled to
0.degree. C. The following were added in order: Example 6 Step 3
salt (328 mg, 1.37 mmol, 1.1 equiv), HOBT (520 mg, 3.85 mmol, 3.1
equiv), EDAC (510 mg, 2.61 mmol, 2.1 equiv), and TEA (0.54 mL, 3.85
mmol, 3.1 equiv). The reaction mixture was allowed to warm to rt
overnight and the DMF removed by rotary evaporation (pump). The
remainder was dried further under vacuum. The residue was dissolved
in EtOAc (100 mL), washed with satd aq NaHCO.sub.3 (50 mL) and satd
aq NaCl (25 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered
and concentrated by rotary evaporation. The product was purified
flash column chromatography on silica gel (3.8.times.15 cm) with a
gradient of 6% (200 mL), 7% (200 mL), and 8% (500 mL)
MeOH/CH.sub.2Cl.sub.2 to give the product as a white solid (460 mg,
1.06 mmol, 85%): MS m/e 434 (m+H).sup.+.
[0367] Step 3 136
[0368] The Step 2 compound (95 mg, 0.22 mmol, 1 equiv) was
dissolved in anhydrous CH.sub.2Cl.sub.2 (2.5 mL) under argon and
cooled to -78.degree. C. The mixture was treated with
diisopropylethylamine (65 .mu.L, 0.37 mmol, 1.7 equiv), and
triethylsilyl triflate (75 .mu.L, 0.33 mmol, 1.5 equiv), and
stirred at 0.degree. C. for 1.5 h. The reaction was mixed with MeOH
(0.5 mL), silica gel (200 mg) and H.sub.2O (2 drops) and stirred at
rt for 18 h. The solvent was removed by rotary evaporation and the
residue purified flash column chromatography on silica
gel(2.5.times.10 cm) with 4% MeOH/CH.sub.2Cl.sub.2 to afford the
product (92 mg, 0.17 mmol, 77%): MS m/e 548 (m+H).sup.+.
[0369] Step 4 137
[0370] The Step 3 compound (90 mg, 0.16 mmol, 1 equiv) was
dissolved in anhydrous pyridine (2 mL) under argon and cooled to
-30.degree. C. Treatment with imidazole (24 mg, 0.35 mmol, 2.1
equiv) and phosphorous oxychloride (66 .mu.L, 0.67 mmol, 4.1
equiv), and continued stirring at -30.degree. C. for 45 min gave a
thick slurry. Volatiles were by rotary evaporation and the cake
dried further under reduced pressure. The product was purified by
flash column chromatography on silica gel (2.5.times.10 cm) with 7%
EtOAc/CH.sub.2Cl.sub.2 to afford the product as a white foam (76
mg, 87%): MS m/e 530 (m+H).sup.+
[0371] Step 5 138
[0372] The Step 4 compound (76 mg, 0.14 mmol) was dissolved in
anhydrous CH.sub.2Cl.sub.2 (1 mL) and cooled to 0.degree. C. and
treated with TFA (1 mL) and H.sub.2O (2 drops) and stirred for 1.5
hr at 0.degree. C. The solvents were removed by rotary evaporation
and the residue was chased with toluene (5 mL) and dried under
reduced pressure. Trituration with Et.sub.2O afforded the title
compound as a white solid (54 mg, 88%): MS m/e 316 (m+H).sup.+.
EXAMPLE 61
[0373] 139
[0374] An oven-dried flask purged with argon was charged with
anhydrous CH.sub.2Cl.sub.2 (3 mL) and cooled to -78.degree. C.
Treatment with diethylaminosulfur trifluoride (DAST, 60 .mu.L, 0.45
mmol, 1.5 equiv), followed by a solution of the Example 60 Step 2
compound (131 mg, 0.30 mmol, 1 equiv) in dry CH.sub.2Cl.sub.2 (3
mL). After 15 min, the reaction was poured into a separatory funnel
containing satd aq NaHCO.sub.3 (25 mL) and the layers were
separated. The aqueous fraction was extracted with CH.sub.2Cl.sub.2
(25 mL), then the combined organic extracts were washed with brine
(10 mL), dried (Na.sub.2SO.sub.4), filtered and concentrated. The
product was purified by flash column chromatography on silica gel
(2.5.times.10 cm) with 5% MeOH/CH.sub.2Cl.sub.2 to give Step 1
compound (124 mg, 0.29 mmol, 94%): MS m/e 436 (m+H).sup.+. 140
[0375] The fluorinated amide from Step 1 (161 mg, 0.37 mmol, 1
equiv) was dissolved in anhydrous pyridine (4 mL) under argon and
cooled to -30.degree. C. The mixture was treated with imidazole (54
mg, 0.77 mmol, 2.1 equiv) and phosphorous oxychloride (143 .mu.L,
1.52 mmol, 4.1 equiv) and stirred at -30.degree. C. for 40 min. The
solvent was removed by rotary evaporation and dried further under
reduced pressure. The product was purified by flash column
chromatography on silica gel (2.5.times.10 cm) with 5%
EtOAc/CH.sub.2Cl.sub.2 to give the Step 2 compound as a white foam
(126 mg, 82%): MS m/e 418 (m+H).sup.+. 141
[0376] The Step 2 compound (125 mg, 0.30 mmol) was dissolved in
TFA/CH.sub.2C1.sub.2 (1:1 v/v, 2 mL), and stirred at rt. After 30
min., the solvents were removed by rotary evaporation, the
remainder was chased with toluene (2.times.5 mL), and the solid
dried under reduced pressure. Trituration with Et.sub.2O afforded
the title compound as a white solid (93 mg, 0.21 mmol, 72%): MS m/e
318 (m+H).sup.+.
EXAMPLE 62
[0377] 142
[0378] The Step 1 compound was prepared beginning with
2-adamantanal and elaborated to the homochiral Boc-amino acid by an
asymmetric Strecker synthesis according to general method G.
143
[0379] The title compound in Example 62 was prepared by the peptide
coupling of the 2-adamantyl amino acid described in Step 1 followed
by dehydration and deprotection as described in general method C.MS
(M+H) 300.
EXAMPLE 63
[0380] 144
[0381] An oven-dried flask equipped with a condenser and drying
tube was charged with norbornane-2-carboxylic acid (4.92 g, 35
mmol, 1 equiv) and treated with bromine (2.1 mL, 41 mmol, 1.15
equiv) and phosphorous trichloride (0.153 mL, 1.8 mmol, 0.05
equiv). The mixture was heated at 85.degree. C. for 7 h protected
from light. Additional bromine (0.4 mL, 7.8 mmol, 0.22 equiv) was
added with continued heating for 1 h. The mixture was cooled to rt,
and Et.sub.2O (100 mL) was added. The mixture was washed with 10%
aq NaHSO.sub.3 (50 mL), H.sub.2O (2.times.50 mL), and brine (25
mL). The ether fraction was dried (Na.sub.2SO.sub.4), filtered and
concentrated by rotary evaporation. The product was purified by
flash column chromatography on silica gel (5.times.15 cm) with 2%
to 4% MeOH/CH.sub.2Cl.sub.2+0.5% HOAc. The product was chased with
hexanes to remove residual HOAc. The isolated material consists of
two inseparable materials (4.7 g), which was used without further
purification in the next step. 145
[0382] The crude product from above,
exo-2-bromonorbornane-1-carboxylic acid (4.7 g, impure) in
Et.sub.2O (80 mL) and MeOH (20 mL), was mixed with
trimethylsilyldiazomethane (2.0 M in hexane, 11.8 mL, 23.6 mol),
and stirred at rt for 1 h. Solvent was removed by rotary
evaporation, and purification of the oil by flash column
chromatography on silica gel (5.times.18 cm) with a gradient of
CH.sub.2Cl.sub.2/hexanes (600 mL each of 20% and 30%) followed by
CH.sub.2Cl.sub.2 afforded the product as a white solid (3.97 g,
0.017 mol, 79% for 2 steps): MS m/e 233/235 (m+H).sup.+. 146
[0383] Methyl exo-2-bromonorbornane-1-carboxylate (2.0 g, 8.58
mmol, 1 equiv) was dissolved in anhydrous THF (50 mL) in an
oven-dried 3-neck flask equipped with a condenser, and purged with
argon. The mixture was treated with AIBN (288 mg, 1.71 mmol, 0.2
equiv) and tributyltin hydride (3.6 mL, 12.87 mmol, 1.5 equiv), and
then heated to reflux for 2 h. The flask was cooled to rt, and the
THF was removed by rotary evaporation to give the crude product.
The product was purified by flash column chromatography on silica
gel (5.times.10 cm) with 5% EtOAc/hexanes. The resulting material
was used in the next step without further purification.
[0384] Step 2 147
[0385] The Step 1 compound was prepared beginning with 1-norbonyl
methyl carboxylate and elaborated to the homochiral Boc amino acid
by an asymmetric Strecker synthesis according to general method
G.
[0386] Step 3 148
[0387] The title compound in Example 63 was prepared by the peptide
coupling of the 1-norbonyl amino acid described in Step 2, followed
by dehydration and deprotection as described in general method C.
MS (M+H) 260.
EXAMPLE 64
[0388] 149
[0389] The Step 1 compound was prepared beginning with
4-formylpyran and elaborated to the homochiral Boc amino acid by an
asymmetric Strecker synthesis according to general method G.
150
[0390] The title compound in Example 64 was prepared by the peptide
coupling of the 4-pyranyl amino acid described in Step 2, followed
by dehydration and deprotection as described in general method C.
MS (M+H) 250.
[0391] General Method H:
[0392] Strecker Synthesis of Racemic Amino Acids. 151 152
[0393] To a stirred solution of 1-phenylcyclo-1-pentanecarboxylic
acid (5.00 g, 26.3 mmol) in 25 mL of THF at 0.degree. C. was added
LAH (52 mL , 52 mmol, 1M) in THF. The reaction mixture was slowly
warmed to rt and then refluxed for 18 h. The reaction was quenched
according to the Fieser procedure: careful addition of 2 mL of
water; 6 mL of 15% NaOH in water; and 2 mL of water. The biphasic
mixture was diluted with 100 mL of ether and the granular white
solid filtered off. The ether fraction was dried over
Na.sub.2SO.sub.4 and evaporated to give 4.30 g (93%) of the Step 1
compound. 153
[0394] To a stirred solution of Step 1 compound (0.80 g, 4.50 mmol)
in 15 mL of CH.sub.2Cl.sub.2 at rt was added celite (5 g) followed
by PCC (1.95 g, 5.00 mmol). After stirring for 3 h the reaction
mixture was diluted with 40 mL of CH.sub.2Cl.sub.2 and filtered
through celite. The filtrate was filtered an additional time
through silica gel resulting in a colorless filtrate. The
CH.sub.2Cl.sub.2 fraction was evaporated to give 0.72 g (91%) of
the aldehyde as a colorless oil. 154
[0395] To a 50-mL round-bottomed flask containing Step 2 compound
(0.72 g, 4.20 mmol) in 8 mL of water at rt was added NaCN (0.20 g,
4.20 mmol) followed by NH.sub.4Cl (0.20 g, 5.00 mmol). To this
reaction mixture was then added methanol (8 mL) and the mixture was
allowed to stir overnight. The reaction mixture was then extracted
with ether (2.times.15 mL), dried (MgSO.sub.4) and concentrated
under reduced pressure to give the crude Strecker product.
[0396] To a 100-mL round-bottomed flask containing the crude
Strecker product was added 10 mL of HOAc and 10 mL of conc. HCl.
The mixture was refluxed overnight. The mixture was concentrated
under reduced pressure to give a yellow solid. The solid was
triturated with 5 mL of 1:1 mixture of ether and hexanes. The white
solid was treated with triethylamine (1.4 mL, 9.99 mmol) and
di-tert-butyldicarbonate (1.00 g, 4.60 mmol) in 50 mL DMF. After 4
h the pH of the mixture was adjusted to 9 with saturated
Na.sub.2CO.sub.3 soln. After an additional 3 h of stirring the
mixture was extracted with 1:1 ether and hexanes and the aqueous
fraction acidified to pH 2 with 5% KHSO.sub.4 solution. The aqueous
phase was washed with ether (2.times.40 mL), the organics dried
(MgSO.sub.4), and evaporated to an oil that was purified by silica
gel flash chromatography with 8:92 methanol:CH.sub.2Cl.sub.2 to
give 0.3 g (23%) of the Boc-protected amino acid as a light oil
(M-H, 318).
EXAMPLE 65
[0397] 155
[0398] The synthesis of the Step 1 compound was described in
general method H for the Strecker synthesis of racemic amino acids.
156
[0399] The title compound in Example 65 was prepared by the peptide
coupling of the cyclopentylphenyl amino acid described in Step 1
and general method H followed by dehydration and deprotection as
described in general method C. MS (M+H) 310.
EXAMPLE 66
[0400] 157
[0401] Step 1 compound was prepared using racemic Strecker
synthesis according to general method H starting from
2,2-dimethyl-phenylacetic acid. 158
[0402] The title compound in Example 66 was prepared by the peptide
coupling of the dimethylphenyl amino acid described in step 1
followed by dehydration and deprotection as described in general
method C. MS (M+H) 284.
EXAMPLE 67
[0403] 159
[0404] N-(Benzyloxycarbonyl) succinimide (5.6 g, 22.4 mmol) was
dissolved in CH.sub.2Cl.sub.2 (25 mL) and the solution was added to
a cooled (0.degree. C.) and stirred solution of diethyl
aminomalonate hydrochloride (5.0 g, 23.6 mmol) and triethylamine
(13.4 mL, 95 mmol) in CH.sub.2Cl.sub.2 (125 ml). The resulting
solution was stirred at 0.degree. C. for 10 min and then at rt for
1 h. The solution was washed with 10% citric acid (2.times.50
mL),10% sodium hydrogen carbonate (2.times.50 mL), and water (50
mL) and was then dried (Na.sub.2SO.sub.4) and evaporated to afford
diethyl N-benzyloxycarbonylaminomalonate as a colorless oil, which
crystallized upon standing at 0.degree. C. (6.3 g) (LC/Mass
+ion):310 (M+H).
[0405] Step 2 160
[0406] Step 1 compound (6.18 g, 20 mmol) was dissolved in dry
ethanol (30 mL) and added to a solution of sodium ethoxide (2.85 g,
8.8 m mol; 21% w/w solution in ethanol (6 mL). A solution of
3-methyl-2-butenal (1.68 g, 20 mmol) in ethanol (12 mL) was added,
and the solution stirred at 25.degree. C. for 24 h. Acetic acid
(0.56 mL) was then added the solution hydrogenated at 50 psi for 24
h using 10% Pd/C (2.0 g) as catalyst. The solution was filtered,
evaporated and the residue chromatographed on silica with
CH.sub.2Cl.sub.2/EtOAc (9:1) to give 2,2-dicarboethoxy-3,3-di-
methyl-pyrrolidine (1.6 g) (LC/Mass, +ion): 244 (M+H).
[0407] This diester (850 mg) was refluxed in 5 M hydrochloric acid
(10 mL)/TFA (1 mL) for 8 h to give, after evaporation, a powdery
white solid. Crystallization from methanol/ether gave
3,3-dimethyl-dl-proline hydrochloride (190 mg) as white crystals mp
110-112.degree. C.
[0408] Step 3 161
[0409] Step 2 compound (173 mg, 0.97 mmol) was dissolved in DMF (3
mL)/water (3 mL). To this clear solution was added triethylamine
(0.46 mL, 3.18 mmol) and di-t-butyl dicarbonate (0.23 g, 1.06
mmol), and the reaction mixture was stirred at rt for 5 h. The
solution was evaporated and the residue chromatographed on silica
column using CH.sub.2Cl.sub.2/methanol (9:1) as eluent to yield
t-butyloxy-carbonyl-3,3-dimethyl-dl-proline (200 mg) as an oil
(LC/Mass, +ion): 244 (M+H).
[0410] Step 4 162
[0411] The title compound in Example 67 was prepared by the peptide
coupling of the t-butyloxycarbonyl-3,3-dimethyl-dl-proline amino
acid described in Step 3 followed by dehydration and deprotection
as described in general method C. MS (M+H) 220.
EXAMPLE 68
[0412] Step 1 163
[0413] Sodium ethoxide (940 mg of 21 wt % solution in ethanol, 2.9
mmol) in ethanol (2 mL) was added to a stirred solution of diethyl
acetamidomalonate (4.31g, 19.8 mmol) in EtOH (23 mL) at rt under
argon. The reaction mixture was cooled to 0.degree. C.; and
trans-2-pentenal (1.51 g, 18.0 mmol) was added dropwise maintaining
the reaction temperature at <5.degree. C. After the addition,
the reaction was allowed to warm to rt, stirred for 4 h, then
quenched with acetic acid (460 .mu.l). The solution was
concentrated in vacuo, and the residue dissolved in EtOAc (25 mL),
washed with 10% NaHCO.sub.3 solution (2.times.5 mL), brine and
dried (MgSO.sub.4). The solution was filtered and concentrated to a
10 mL volume, then heated to reflux and diluted with hexane (20
mL). Upon cooling to rt, the title compound precipitated and was
collected to give 3.0 g (50%) of the Step 1 compound (mp
106-109.degree. C.; LC/Mass: +ions, 324 M+Na).
[0414] Step 2 164
[0415] To a solution of Step 1 compound (2.87 g, 9.5 mmol) and
triethylsilane (2.28 mL, 14.3 mmol) in CH.sub.2Cl.sub.2 (30 mL)
under argon was added TFA (7.35 mL, 95.3 mmol) dropwise with
stirring while maintaining the internal temperature at 25.degree.
C. by means of an ice bath. After stirring for 4 h at rt, the
solution was concentrated. The residue was diluted with
CH.sub.2Cl.sub.2 (100 mL), then treated with H.sub.2O (50 mL) and
solid Na.sub.2CO.sub.3 with vigorous stirring until the mixture was
basic. The organic layer was separated, dried (Na.sub.2SO.sub.4),
filtered, then concentrated to give the Step 2 compound as a yellow
oil which was used without further purification (LC/Mass: +ions,
308 M+Na).
[0416] Step 3 165
[0417] Step 2 compound (3.73 g, 9.5 mmol) was suspended in 6 N HCl
(20 mL) and HOAc (5 mL) and heated at reflux for 20 h. The reaction
mixture was then cooled, washed with EtOAc (20 mL), then
concentrated to give an oil which crystallized upon trituration
with ether to give the title compound (1.2 g, 70.6%) (LC/Mass,
+ion): 144 (M+H).
[0418] Step 4 166
[0419] Step 3 compound (692 mg, 3.76 mmol) was dissolved in acetone
(12 mL)/water (12 mL). To this clear solution was added
triethylamine (1.9 mL, 12.8 mmol) and di-t-butyl dicarbonate (928
mg, 4.24 mmol). The reaction mixture was stirred at rt for 18 h.
The solvents were evaporated and the residue chromatographed on
silica with 1:9 methanol:CH.sub.2Cl.sub.2 to give the Step 4
compound as an oil (LC/Mass: +ions, 266 M+Na).
[0420] Step 5 167
[0421] Example 68 compound was prepared by peptide coupling of Step
4 amino acid followed by dehydration and deprotection as described
in general method C (MS (M+H) 234).
EXAMPLE 69
[0422] 168
[0423] Sodium ethoxide (940 mg, 2.9 mmol; 21% w/w solution in
ethanol) in ethanol (2 mL) was added to a stirred solution of
diethyl acetamidomalonate (4.31 g, 19.8 mmol) in EtOH (23 mL) at rt
under argon. The reaction mixture was cooled to 0.degree. C.; and
4-methyl-2-pentenal (1.77 g, 18.0 mmol)was added dropwise
maintaining the reaction temperature at <5.degree. C. After the
addition, the reaction was allowed to warm to rt, stirred for 4 h,
then quenched with acetic acid (460 .mu.l). The solution was
concentrated and the remainder dissolved in EtOAc (25 mL). The
organics were washed with 10% NaHCO.sub.3 solution (2.times.5 mL),
brine and dried (MgSO.sub.4). The solution was filtered and
concentrated to 10 mL volume, then heated to reflux and treated
with hexane (20 mL). On cooling, the Step 1 compound precipitated
and was collected (3.3 g) (LC/Mass, +ion): 338 (M+Na).
[0424] Step 2 169
[0425] To a solution of Step 1 compound (3.0 g, 9.5 mmol) and
triethylsilane (2.28 mL, 14.3 mmol) in CH.sub.2Cl.sub.2 (30 mL)
under argon was added TFA (7.35 mL, 95.3 mmol) dropwise with
stirring while maintaining the internal temperature at 25.degree.
C., by means of an ice bath. After stirring for 4 h at rt, the
solution was concentrated, the residue diluted with
CH.sub.2Cl.sub.2 (100 mL), then treated with H.sub.2O (50 mL) and
solid Na.sub.2CO.sub.3 with vigorous stirring until the mixture was
basic. The organic layer was separated, dried (Na.sub.2SO.sub.4),
filtered, then concentrated to give the title compound as an oil
which was used without further purification (LC/Mass:+ions, 300
M+H).
[0426] Step 3 170
[0427] Step 2 compound (3.8 g, 9.5 mmol) was suspended in 6 N HCl
(20 mL) and HOAc (5 mL) and heated at reflux for 20 h. The reaction
mixture was cooled, washed with EtOAc (20 mL), then concentrated to
give an oil which crystallized upon trituration with ether to give
the step 3 compound (1.4 g, 76.0%). LC/Mass: +ions, 158 (M+H).
[0428] Step 4 171
[0429] Step 3 compound (728 mg, 3.76 mmol) was dissolved in a 1:1
acetone/water solution (24 mL). To this clear solution was added
triethylamine (1.9 mL, 12.8 mmol) and di-t-butyl dicarbonate (928
mg, 4.24 mmol). The reaction mixture was stirred at rt for 18 h.
The solution was evaporated and the residue chromatographed on
silica column using CH.sub.2Cl.sub.2/methanol (9:1) as eluent to
give the title compound as an oil (LC/Mass, +ion): 258 (M+H).
[0430] Step 5 172
[0431] Example 69 compound was prepared by peptide coupling of Step
4 amino acid followed by dehydration and deprotection as described
in general method C (MS (M+H) 248).
EXAMPLE 70
[0432] Step 1 173
[0433] Step 1 compound was prepared by the procedure described in
General Method C starting from N-Boc-S-t-butylcysteine.
[0434] Step 2 174
[0435] A 25-mL round-bottomed flask equipped with a magnetic
stirring bar and N.sub.2 inlet was charged with Step 1 compound (78
mg, 0.21 mmol) and chloroform (3 mL). The mixture was cooled to
0.degree. C. and treated with m-chloroperoxybenzoic acid (85 mg,
0.44 mmol) in CHCl.sub.3 (2 mL). After 3 h the solution was diluted
with CHCl.sub.3 (7 mL), washed with 5% NaHCO.sub.3 (2.times.5 mL),
H.sub.2O and dried over Na.sub.2SO.sub.4. Removal of solvent gave
crude sulfoxide (100 mg), which was used without further
purification (LC/Mass, +ions): 384 (M+H).
[0436] Step 3 175
[0437] Trifluoroacetic acid (1.5 mL) was added to a cooled
(0.degree. C.) solution of Step 2 compound (100 mg, 0.26 mmol) in 5
mL CH.sub.2Cl.sub.2. The solution was then stirred at 0.degree. C.
for 1.5 h, diluted with CH.sub.2Cl.sub.2 (5 mL) and concentrated
under reduced pressure to a thick oil. The product was purified by
reverse phase preparative column chromatography on a YMC S5 ODS
20.times.100 mm column to give the title compound of Example 70 ,
17 mg, 16%. Purification conditions: gradient elution from 10%
methanol/water/0.1 TFA to 90% methanol/water/0.1 TFA over 15 min 5
min hold at 90% methanol/water/0.1 TFA. Flow rate: 20 mL/min.
Detection wavelength: 220. Retention Time 10 Min (LC/Mass, +ion):
284 (M+H).
EXAMPLE 71
[0438] 176
[0439] A 25-mL round-bottomed flask equipped with a magnetic
stirring bar and N.sub.2 inlet was charged with compound from
Example 70, Step 1 (78 mg, 0.21 mmol) in chloroform (3 mL). The
mixture was cooled to 0.degree. C. and treated with
m-chloroperoxybenzoic acid (144 mg, 0.84 mmol) in CHCl.sub.3 (2
mL). After 30 min at rt, the solution was diluted with CHCl.sub.3
(7 mL), washed with 5% NaHCO.sub.3 (2.times.10 mL), H.sub.2O and
dried over Na.sub.2SO.sub.4. Removal of solvent gave the crude
sulfone (100 mg), which was used without further purification
(LC/Mass, +ion): 344 (M+H-Bu).
[0440] Step 2 177
[0441] Trifluoroacetic acid (1.5 mL) was added to a cooled
(0.degree. C.) and stirred solution of Step 1 compound (100 mg,
0.26 mmol) in 5 mL CH.sub.2Cl.sub.2. The solution was stirred at
0.degree. C. for 30 min, diluted with CH.sub.2Cl.sub.2 (5 mL) and
concentrated under reduced pressure to a thick oil. The product was
purified by reverse phase preparative column chromatography on a
YMC S5 ODS 20x100 mm column to give the title compound, 14 mg, 17%.
Purification conditions: gradient elution from 10%
methanol/water/0.1 TFA to 90% methanol/water/0.1 TFA over 15 min. 5
min hold at 90% methanol/water/0.1 TFA. Flow rate:20 mL/min.
Detection wavelength: 220. Retention Time 10 Min. (LC/Mass, +ion):
300 (M+H).
EXAMPLE 72
[0442] 178
[0443] The title compound was prepared following a published
procedure (Sasaki et al, Tetrahedron Lett. 1995, 36, 3149, Sasaki
et al. Tetrahedron 1994, 50, 7093) used to synthesize
(2S,3R,4S)-N-Boc-3,4-metha- no-L-proline carboxylate. The
corresponding amide was prepared by general method A and
deprotected with TFA to give the TFA salt also as described in
general method A.
EXAMPLE 73
[0444] 179
[0445] The title compound was prepared by coupling
(2S,3R,4S)-3,4-methano-- L-proline carboxamide-N-trifluoroacetate
described in Example 72 with L-cyclohexylglycine and then
dehydrated to the amide with POCl.sub.3/imidazole and deprotected
(N-terminal nitrogen) with TFA using general C (FAB MH+ 248).
EXAMPLE 74
[0446] 180
[0447] The title compound was prepared by coupling
(2S,3R,4S)-3,4-methano-- L-proline carboxamide-N-trifluoroacetate
described in Example 72 with L-tert-butylglycine and then
dehydrated to the amide with POCl.sub.3/imidazole and deprotected
(N-terminal nitrogen) with TFA using general C (FAB MH+ 222).
EXAMPLE 75
[0448] 181
[0449] The title compound was prepared by coupling
(2S,3R,4S)-3,4-methano-- L-proline carboxamide-N-trifluoroacetate
described in Example 72 with L-valine and then dehydrated to the
amide with POCl.sub.3/imidazole and deprotected (N-terminal
nitrogen) with TFA using general C (FAB MH+207).
EXAMPLE 76
[0450] 182
[0451] The title compound was prepared by coupling
(2S,3R,4S)-3,4-methano-- L-proline carboxamide-N-trifluoroacetate
described in Example 72 with
N-(tert-butyloxycarbonyl)-(1'ethylcyclopentyl)glycine described in
General Method B and then dehydrated to the amide with
POCl.sub.3/imidazole and deprotected (N-terminal nitrogen) with TFA
using general C (FAB MH+ 262).
EXAMPLE 77
[0452] 183
[0453] The title compound was prepared by coupling
(2S,3R,4S)-3,4-methano-- L-proline carboxamide-N-trifluoroacetate
described in Example 72 with
N-(tert-butyloxycarbonyl)-(1'vinylcyclopentyl)glycine described in
General Method B and then dehydrated to the amide with
POCl.sub.3/imidazole and deprotected (N-terminal nitrogen) with TFA
using General Method C (FAB MH+ 260).
EXAMPLE 78
[0454] 184
[0455]
N-[((S)-cyclopentylvinyl)-N-tert-butoxycarbonylglycinyl]-(2S,4S,5S)-
-2-cyano-4,5-methano-L-prolylamide (70 mg, 0.19 mmol) described in
General Method C, Step 2 was dissolved in a mixture of 2 mL
t-BuOH/3 mL THF and N-methylmorpholine-N-oxide (33mg, 0.28 mmol)
was added followed by osmium tetroxide (0.1 mmol, 50 mol%). The
reaction was quenched with 1 mL of 10% aqueous Na.sub.2SO.sub.3 and
was taken up in EtOAc and washed with H.sub.2O 5 mL, dried
(Na.sub.2SO.sub.4), filtered, evaporated and purified by silica gel
flash chromatography (5% MeOH/CH.sub.2Cl.sub.2) to give 41 mg (55%)
of the protected diol as an oil. The title compound was obtained by
deprotection of the amine functionality with TFA according to
General Method C (FAB MH+ 294).
EXAMPLE 79
[0456] 185
[0457] General Procedure I:
[0458] Synthesis of Quaternary Amino Acids Via Michael Addition to
Malonates followed by Selective Hydrolysis and Curtius
Rearrangement. Examples 79-84.
[0459] Cyclohexanone and diethylmalonate underwent Knoevenagel
condensation mediated by titanium tetrachloride in THF and
CCl.sub.4 to give 40. Copper (I) mediated Grignard addition of
methylmagnesium bromide gave 41 which was selectively saponified to
42. Curtius rearrangement with trapping by benzyl alcohol gave 43
which was converted to 44 by a standard deprotection-protection
protocol. Ester 44 was saponified to give the quaternary amino acid
45. 186
[0460] Step 1 187
[0461] According to literature procedure (Tetrahedron 1973, 29,
435), a mixture of dry tetrahydrofuran (400 mL) and dry carbon
tetrachloride (50 mL) was cooled to 0.degree. C. (ice-salt bath)
and treated with titanium tetrachloride (22.0 mL, 0.2 mole). The
resulting yellow suspension was stirred at 0.degree. C. for 5 min,
treated sequentially with cyclohexanone (10.3 mL, 0.1 mole) and
distilled diethylmalonate (15.2 mL, 0.1 mole) then stirred at
0.degree. C. for 30 min. The reaction mixture was then treated with
a solution of dry pyridine (32 mL, 0.40 mole) in dry THF (60 mL),
stirred at 0.degree. C. for 1.0 h, then at rt for 72 h. The
reaction mixture was quenched with water (100 mL), stirred for 5
min then extracted with ether (2.times.200 mL). The combined
organic extracts were washed with saturated sodium chloride (100
mL), saturated sodium bicarbonate (100 mL) and brine (100 mL),
dried over anhydrous magnesium sulfate, filtered and concentrated.
Flash chromatography using 5% EtOAc in hexane gave step 1 compound
as a light yellow oil. Yield: 5.25 g (22%). MS (M+Na) 263.
[0462] Step 2 188
[0463] According to literature (Org. Syn. VI, 442, 1988; Liebigs
Ann. Chem. 1981, 748) a mixture of 3.0 M methylmagnesium iodide
(3.1 mL, 9.36 mmol) and cuprous chloride (9.0 mg) was stirred at
0.degree. C. (ice-salt water bath), treated with a solution of Step
1 compound (1.5 g, 6.24 mmol) in dry ether (1.8 mL) over 5 min and
stirred at 0.degree. C. for 1 h, then at rt for 40 min. The mixture
was slowly added to a slurry of ice and water (15 mL), treated
dropwise with 10% HCl (3.7 mL) then extracted with EtOAc
(3.times.25 mL). The combined organic extracts were washed with 1%
sodium thiosulfate (2.0 mL) and saturated sodium chloride (2.0 mL),
dried over anhydrous magnesium sulfate, filtered, and concentrated.
Flash chromatography on a silica gel column using 5% ether in
hexane (1.0 L) gave step 2 compound as a clear syrup. Yield: 1.09
g,(68%). MS (M+H)257.
[0464] Step 3 189
[0465] A solution of Step 2 compound (1.09 g, 4.03 mmol) in a
mixture of methanol (5.4 mL) and water (2.7 mL) was treated with 1N
sodium hydroxide (4.84 mL, 4.84 mmol or 1.2 equiv) and stirred at
rt for 6 days. The reaction mixture still showed the presence of
starting material, so THF (4.0 mL) was added and the entire mixture
stirred for another 2 days. The solution was evaporated to dryness
and the resulting syrup partitioned between water (8.0 mL) and
ether (15 mL). The aqueous phase was acidified with 1N hydrochloric
acid (4.8 mL) to pH 2-3 and extracted with EtOAc (3.times.25 mL).
The combined organic extracts were washed with brine (10.0 mL),
dried over anhydrous magnesium sulfate, filtered, and concentrated
to give step 3 compound as a thick syrup. Yield: 875 mg, (95.1%).
MS (M +H) 229.
[0466] Or alternately: solutions of the diester in a mixture of
ethanol, THF, dioxane and water or mixtures thereof may be
hydrolyzed with sodium hydroxide.
[0467] Step 4 190
[0468] According to literature (J. Org. Chem 1994, 59, 8215), a
solution of Step 3 compound (0.875 g, 3.83 mmol) in dry benzene
(4.0 mL) was treated with triethylamine (0.52 mL, 3.83 mmol) and
diphenylphosphoryl azide (0.85 mL, 3.83 mmol), refluxed under
nitrogen for 1 h and cooled to rt. The solution was treated with
benzyl alcohol (0.60 mL, 5.75 mmol or 1.5 equiv), refluxed for 17
h, cooled then diluted with ether (40 mL). The solution was washed
with 10% aqueous citric acid (2.times.3 mL),back-extracting the
citric acid wash with ether (40 mL). The combined organic extracts
were washed with 5% sodium bicarbonate (2.times.3 mL), dried
(MgSO.sub.4), filtered, and concentrated. Flash chromatography on
silica gel of the crude product with 10% EtOAc in hexane (1.0 L)
gave step 4 compound as a clear thick syrup. Yield: 1.15 g (90%).
MS(M+H) 334.
[0469] Step 5 191
[0470] A solution of Step 4 compound (1.15 g, 3.46 mmol) in EtOAc
(60 mL) was treated with palladium hydroxide on carbon (298 mg) and
hydrogenated at rt for 20 h. The mixture was filtered through a
celite pad and then washing the pad well with EtOAc (3.times.25 mL)
then the filtrate was concentrated to give the free amine. A
solution of the amine in tetrahydrofuran (12 mL) and water (12 mL)
was treated with di-t-butyl dicarbonate (1.0 g, 4.58 mmol or 1.48
equiv) and potassium carbonate (854 mg, 6.18 mmol or 2.0 equiv),
then stirred at rt for 20 h. The reaction mixture was partitioned
between water (8 mL) and diethyl ether (3.times.40 mL) and the
combined organic extracts were washed with brine (8 mL), dried
(MgSO.sub.4), filtered, and concentrated. Flash chromatography of
the crude product with 10% EtOAc in hexane (1 L) gave step 5
compound as a clear thick syrup. Yield: 1.18 g (100%). MS:(M+H)
300.
[0471] Other methods can also be employed, for example: According
to Tetrahedron Lett. 1988, 29, 2983, where a solution of the
benzylcarbamate in ethanol may be treated with triethylsilane (2
equiv), di-t-butyldicarbonate (1.1 equiv), catalytic palladium
acetate and triethylamine (0.3 equiv) to give the BOC-protected
amine in a "one-pot" manner.
[0472] Or alternately: Solutions of the benzylcarbamate in methanol
may be subjected to hydrogenolysis in the present of
di-t-butyldicarbonate to give the BOC-protected amine in a
"one-pot" manner.
[0473] Step 6 192
[0474] A solution of Step 5 compound (1.18 g, 3.09 mmol) in dioxane
(8.0 mL) was treated with 1N sodium hydroxide (9.1 mL, 9.1 mmol or
3.0 equiv) and stirred at 60.degree. C. (oil bath) for 28 h. The
reaction mixture was concentrated to a syrup which was dissolved in
water (15 mL) and extracted with ether (25 mL). The aqueous phase
was acidified to pH 2-3 with 1N hydrochloric acid (9.2 mL) then
extracted with EtOAc (3.times.50 mL). The combined organic extracts
were washed with saturated sodium chloride (10 mL), dried
(MgSO.sub.4), filtered, and concentrated to give Step 6 compound as
an off-white solid. Yield: 808 mg (96%). MS (M+H) 272.
[0475] Step 7 193
[0476] The title compound was prepared from Step 6 compound
according to the procedure in General Method C where the amino acid
was coupled, the amide was dehydrated, and the protecting group
removed to give the title compound. MS (M+H) 262.
[0477] Compounds 90-100 were prepared by General Method I and
General Method C starting from cyclohexanone, cyclopentanone and
cyclobutanone, and employing methyl-, ethyl-, allyl- and
propylmagnesium halides as Grignard reagents.
5TABLE 5 194 MS Data Example # Cycloalkane R M + H 79 cyclohexane
Methyl 262 80 cyclohexane Ethyl 276 81 cyclopentane Methyl 248 82
cyclopentane Allyl 274 83 cyclopentane Propyl 276 84 cyclobutane
Methyl 234
EXAMPLE 85
[0478] Step 1 195
[0479] According to Example 79: A mixture of dry carbon
tetrachloride (50 mL) was cooled to 0.degree. C. (ice-salt bath)
and treated with titanium tetrachloride (11.0 mL, 0.1 mol). The
resulting yellow suspension was stirred at 0.degree. C. for 5 min,
treated sequentially with cyclopentanone (4.42 mL, 0.05 mol) and
distilled diethylmalonate (7.6 mL, 0.05 mol) then stirred at
0.degree. C. for 30 min. The reaction mixture was then treated with
a solution of dry pyridine (16 mL, 0.20 mol) in dry THF (30 mL),
stirred at 0.degree. C. for 1.0 h, then at rt for 20 h. The
reaction mixture was quenched with water (50 mL), stirred for 5 min
then extracted with ether (2.times.100 mL). The combined organic
extracts were washed with saturated sodium chloride (50 mL),
saturated sodium bicarbonate (50 mL) and brine (50 mL), dried
(MgSO.sub.4), filtered and concentrated. Flash chromatography using
5% EtOAc in hexane gave Step 1 compound as a light yellow oil.
Yield: 7.67 g (68%). MS (M+H) 226.
[0480] Step 2 196
[0481] A solution of Step 1 compound (1.00 g, 4.42 mmol) in
methanol (50 mL) was treated with 10% Pd/C (0.20 g, 10 mol%) and
hydrogenated (balloon pressure) at rt for 20 h. The mixture was
diluted with methanol and filtered through a pad of celite. The
filtrate was concentrated and purified by flash column
chromatography on silica gel with 7% EtOAc in hexanes to give 0.84
g (91%) of Step 2 compound. MS (M+H) 229.
[0482] Step 3 197
[0483] The Step 3 compound was prepared by the process outlined in
General Method H, where the ester underwent hydrolysis, Curtius
Rearrangement, protecting group exchange, and again final ester
hydrolysis.
[0484] Step 4 198
[0485] The title compound was prepared from Step 3 compound
according to the procedure in General Method C where the amino acid
was coupled, the amide was dehydrated, and the protecting group
removed to give the title compound. MS (M+H)234.
[0486] Examples 86 and 87 were prepared by the procedures used for
Example 85 starting from cyclohexanone and cyclobutanone
respectively.
6 199 Mass Spec Example # Cycloalkane M + H 85 cyclopentyl 234 86
cyclohexyl 248 87 cyclobutyl 220
EXAMPLE 89
[0487] 200
[0488] Step 1 201
[0489] Step 1 compound was prepared in Example 6 Step 1.
[0490] Step 2 202
[0491] The title compound was prepared from Step 1 compound
according to General Method C, where the carboxylic acid underwent
a peptide coupling, the amide dehydration and protecting group
removal. MS (M+H) 218.
EXAMPLES 90 TO 99
[0492] Examples of compounds where X=H include the following
compounds which may be prepared employing procedures as described
hereinbefore.
7 203 Ex. # n x y R.sup.1 R.sup.2 R.sup.3 R.sup.4 90 0 0 1 t-Bu H H
-- 91 0 0 1 adamantyl H H -- 92 0 0 1 204 H H -- 93 0 0 1 205 H Me
-- 94 0 1 0 t-Bu H H -- 95 0 1 0 adamantyl H H -- 96 0 1 0 206 H H
-- 97 0 1 0 207 H Me -- 98 1 0 1 H H H t-Bu 99 1 1 0 Me H H
t-Bu
EXAMPLES 100 TO 109
[0493] Examples of compounds where n=1 include the following
compounds which may be prepared employing procedures as described
hereinbefore.
8 208 Ex. # X x y R.sup.1 R.sup.2 R.sup.3 R.sup.4 100 CN 0 1 H H H
t-Bu 101 CN 0 1 H H H adamantyl 102 CN 0 1 H Me H 209 103 CN 0 1
210 H Me H 104 CN 1 0 t-Bu H H H 105 CN 1 0 adamantyl H H Me 106 CN
1 0 211 Et H H 107 CN 1 0 H H Me 212 108 H 0 1 t-Bu H H H 109 H 1 0
Me H H t-Bu
* * * * *