BACKGROUND OF THE INVENTION
[0001] The present invention is directed to compounds that are inhibitors of cysteine proteases,
in particular, cathepsins B, K, L, F, and S and are therefore useful in treating diseases
mediated by these proteases. The present invention is directed to pharmaceutical compositions
comprising these compounds and processes for preparing them.
STATE OF THE ART
[0002] Cysteine proteases represent a class of peptidases characterized by the presence
of a cysteine residue in the catalytic site of the enzyme. Cysteine proteases are
associated with the normal degradation and processing of proteins. However, the aberrant
activity of cysteine proteases, for example as a result of increased expression or
enhanced activation, may have pathological consequences. In this regard, certain cysteine
proteases are associated with a number of disease states, including arthritis, muscular
dystrophy, inflammation, tumor invasion, glomerulonephritis, malaria, periodontal
disease, metachromatic leukodystrophy and others. For example, increased cathepsin
B levels and redistribution of the enzyme are found in tumors; thus, suggesting a
role for the enzyme in tumor invasion and metastasis. In addition, aberrant cathepsin
B activity is implicated in such disease states as rheumatoid arthritis, osteoarthritis,
pneumocystis carinii, acute pancreatitis, inflammatory airway disease and bone and
joint disorders.
[0003] The prominent expression of cathepsin K in osteoclasts and osteoclast-related multinucleated
cells and its high collagenolytic activity suggest that the enzyme is involved in
osteoclast-mediated bone resorption and, hence, in bone abnormalities such as occurs
in osteoporosis. In addition, cathepsin K expression in the lung and its elastinolytic
activity suggest that the enzyme plays a role in pulmonary disorders as well.
[0004] Cathepsin L is implicated in normal lysosomal proteolysis as well as in several disease
states, including, but not limited to, metastasis of melanomas. Cathepsin S is implicated
in Alzheimer's disease and certain autoimmune disorders, including, but not limited
to juvenile onset diabetes, multiple sclerosis, pemphigus vulgaris, Graves' disease,
myasthenia gravis, systemic lupus erythemotasus, rheumatoid arthritis and Hashimoto's
thyroiditis. In addition, cathepsin S is implicated in: allergic disorders, including,
but not limited to asthma; and allogeneic immune responses, including, but not limited
to, rejection of organ transplants or tissue grafts.
[0005] In view of the number of diseases wherein it is recognized that an increase in cysteine
protease activity contributes to the pathology and/or symptomatology of the disease,
molecules which inhibit the activity of this class of enzymes, in particular molecules
that inhibit cathepsins B, K, L, F, and/or S, will therefore be useful as therapeutic
agents.
SUMMARY OF THE INVENTION
[0007] In one aspect, this invention is directed to a compound of Formula I:

wherein:
[0008] R
1 is aryl or heteroaryl, wherein the aryl ring or heteroaryl ring is optionally substituted
by one, two, or three groups independently selected from alkyl, halo, hydroxy, hydroxyalkyl,
alkoxy, alkoxyalkyl, haloalkyl, haloalkoxy, cyano, nitro, acyl, aryl, aryloxy, arylsulfonyl,
heteroaryl, heteroaryloxy, heteroarylsulfonyl, heterocyclyl, heterocyclyloxy, cycloalkyl,
cycloalkyloxy, carboxy, allcoxycarbonyl, alkylsulfonyl, alkylsulfinyl, aminosulfonyl,
and aminoalkyl;
[0009] Y is oxygen or -S(O)m, in which m is 0, 1, or 2;
[0010] R
2 is hydrogen, R
7-C≡C-, or cis or trans R
7-CH=CH-, in which R
7 is lower alkyl of 1-3 carbon atoms or cycloalkyl of 3-6 carbon atoms;
[0011] R
3 is hydrogen or lower alkyl of 1-3 carbon atoms;
[0012] R
4 is -A-X-R
8, in which A is alkylene of 1-3 carbon atoms optionally substituted by one, two, or
three groups independently selected from alkyl and halo, X is a covalent bond, oxygen
or -S(O)
n, in which n is 0, 1 or 2, and R
8 is hydrogen, alkyl, haloalkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl, heteroaryl,
heteroaralkyl, heterocyclyl, or heterocyclylalkyl, all of which are optionally substituted
with 1, 2, or 3 substituents selected from the group consisting of lower alkyl of
1-4 carbon atoms, halo, and cyano;
[0013] with the proviso that R
8 cannot be hydrogen when X is oxygen or -S(O)
n;
[0014] E is a covalent bond or -CH(R
9)-C(O)-C(O)-NH-, in which R
9 is hydrogen or lower alkyl of 1-6 carbon atoms optionally substituted by one, two,
three, or four groups independently selected from halo and cycloalkyl of 3-7 carbon
atoms;
[0015] Z is -C(R
5)(R
6)-R
10; in which
[0016] R
5 is hydrogen or lower alkyl of 1-4 carbon atoms; and
[0017] R
6 is hydrogen, lower alkyl of 1-4 carbon atoms, cycloalkyl, or aryl; or
[0018] R
5 and R
6 when taken together with the carbon to to which they are attached form a cycloalkyl
group of 3-6 carbon atoms optionally substituted by lower alkyl of 1-4 carbon atoms,
halo, or hydroxyl; and;
[0019] R
10 is hydrogen or cyano;
[0020] with the proviso that when E is a covalent bond, R
10 cannot be hydrogen; and with the proviso that when E is -CH(R
9)-C(O)-C(O)-NH-, R
10 cannot be cyano.
[0021] or a pharmaceutically salt or N-oxide thereof.
[0022] In a second aspect, this invention is directed to a pharmaceutical composition comprising
a compound of Formula I or a pharmaceutically acceptable salt or N-oxide thereof and
at least one pharmaceutically acceptable excipient.
[0023] The present invention also provides a pharmaceutical composition as defined above
for use in a method for treating a disease in an animal mediated by Cathepsin B, K,
L, F or S, which method comprises administering to the animal said pharmaceutical
composition optionally in admixture with one or more suitable excipients. Optionally
the disease is asthma, arthritis, atherosclerosis, COPD, MS, or psoriasis.
[0024] The present invention also provides a compound of Formula I or a pharmaceutically
acceptable salt or N-oxide thereof for use in the treatment of the human or animal
body by therapy.
[0025] The therapy may be e.g. a method for treating a disease in an animal mediated by
cysteine proteases, which method comprises administering to the animal a therapeutically
effective amount of a compound of Formula I or a pharmaceutically acceptable salt
thereof
[0026] Processes are described for preparing compounds of Formula I and pharmaceutically
acceptable salts or prodrugs thereof.
[0027] A method is described of treating a patient undergoing a therapy wherein the therapy
causes an immune response, in particular a deleterious immune response, in the patient,
comprising administering to the patient a compound of Formula I or a pharmaceutically
acceptable salt thereof. Typically, the immune response is mediated by MHC class II
molecules. The compounds of this invention can be administered prior to, simultaneously,
or after the therapy. The therapy may involve treatment with a biologic.
[0028] This invention is directed to the use of a compound of Formula I or a pharmaceutically
acceptable salt thereof for the manufacture of a medicament.
DETAILED DESCRIPTION OF THE INVENTION
Definitions:
[0029] Unless otherwise stated, the following terms used in the specification and claims
are defined for the purposes of this Application and have the following meanings.
[0030] "Alkyl" represented by itself means a straight or branched, saturated aliphatic radical
containing 1, 2, 3, 4, 5, or 6 carbon atoms, unless otherwise indicated e.g., methyl,
ethyl, n-propyl, isopropyl, butyl,
sec-butyl, isobutyl,
tert-butyl, n-pentyl, n-hexyl, and the like.
[0031] "Alkylene", unless indicated otherwise, means a straight or branched, saturated aliphatic,
divalent radical having 1, 2, 3, 4, 5, or 6 carbon atoms, e.g., methylene (-CH
2-), ethylene (-CH
2CH
2-), trimethylene (-CH
2CH
2CH
2-), tetramethylene (-CH
2CH
2CH
2CH
2-) 2-methyltetramethylene (-CH
2CH(CH
3)CH
2CH
2-), pentamethylene (-CH
2CH
2CH
2CH
2CH
2-), and the like.
[0032] "Amino" means an -NH
2 radical.
[0033] "Alkylamino" or "dialkylamino" refers to a -NHR and NRR' radical respectively, where
R and R' are independently alkyl groups as defined above e.g., methylamino, dimethylamino,
and the like.
[0034] "Alkoxy" refers to an -OR radical where R is an alkyl group as defined above e.g.,
methoxy, ethoxy, and the like.
[0035] "Alkoxycarbonyl" refers to a -C(O)OR radical where R is an alkyl group as defined
above e.g., methoxycarbonyl, ethoxycarbonyl, and the like.
[0036] "Alkoxycarbonylalkyl" means an -(alkylene)-C(O)OR radical where R is alkyl as defined
above e.g., methoxycarbonylmethyl, 2-, or 3-ethoxycarbonylmethyl, and the like.
[0037] "Alkoxyalkyl" means a linear monovalent hydrocarbon radical of 1, 2, 3, 4, 5, or
6 carbon atoms or a branched monovalent hydrocarbon radical of 3, 4, 5, or 6 carbons
substituted with at least one alkoxy group, preferably one or two alkoxy groups, as
defined above, e.g., 2-methoxy-ethyl, 1-, 2-, or 3-methoxypropyl, 2-ethoxyethyl, and
the like.
[0038] "Alkoxyalkyloxyalkyl" refers to a -(alkylene)-O-(alkylene)-OR radical where R is
an alkyl group as defined above, e.g., 2-methoxyethyloxymethyl, 3-methoxypropyloxyethyl,
and the like.
[0039] "Aminoalkyl" means a linear monovalent hydrocarbon radical of 1, 2, 3, 4, 5, or 6
carbon atoms or a branched monovalent hydrocarbon radical of 3, 4, 5, or 6 carbon
atoms substituted with at least one, preferably one or two, -NRR' where R is hydrogen,
alkyl, or - COR
a where R
a is alkyl, and R' is hydrogen or alkyl as defined above e.g., aminomethyl, methylaminoethyl,
dimethylaminoethyl, 1,3-diaminopropyl, acetylaminopropyl, and the like.
[0040] "Aminosulfonyl" refers to an -SO
2R radical where R is -NRR' where R is hydrogen, alkyl, or -COR
a where R
a is alkyl, and R' is hydrogen or alkyl as defined above e.g., aminosulfonyl, methylaminosulfonyl,
dimethylaminosulfonyl, and the like.
[0041] "Alkylthio" refers to an -SR radical where R is an alkyl group as defined above e.g.,
methylthio, ethylthio, and the like.
[0042] "Alkylsulfinyl" refers to an -S(O)R radical where R is an alkyl group as defined
above e.g., methylsulfinyl, ethylsulfinyl, and the like.
[0043] "Alkylsulfonyl" refers to an -SO
2R radical where R is an alkyl group as defined above e.g., methylsulfonyl, ethylsulfonyl,
and the like.
[0044] "Acyl" refers to a -COR radical where R is hydrogen, alkyl, haloalkyl, aryl, aralkyl,
heteroaryl, heteroaralkyl, or heterocyclyl as defined herein, e.g., formyl, acetyl,
trifluoroacetyl, benzoyl, piperazin-1-ylcarbonyl, and the like.
[0045] "Aminocarbonyl" refers to a -CONRR' radical where R is hydrogen or alkyl and R' hydrogen,
alkyl, aryl, aralkyl, heteroaryl, or heteroaralkyl.
[0046] "Animal" includes humans, non-human mammals (e.g., dogs, cats, rabbits, cattle, horses,
sheep, goats, swine, deer, and the like) and non-mammals (e.g., birds, and the like).
[0047] "Aromatic" refers to a moiety wherein the constituent atoms make up an unsaturated
ring system, all atoms in the ring system are
sp2 hybridized and the total number of pi electrons is equal to 4n+2.
[0048] "Aryl" refers to a monocyclic or fused bicyclic ring assembly containing 6, 7, 8,
9 or 10 ring carbon atoms wherein each ring is aromatic e.g., phenyl or naphthyl.
[0049] "Aralkyl" refers to an -(alkylene)-R radical where R is aryl as defined above e.g.,
benzyl, phenethyl, and the like.
[0050] "Aryloxy" refers to an -OR radical where R is aryl as defined above e.g., phenoxy,
and the like.
[0051] "Aryloxyalkyl" refers to an -(alkylene)-OR radical where R is aryl as defined above
e.g., phenoxymethyl, 2-, or 3-phenoxymethyl, and the like
[0052] "Arylsulfonyl" refers to an -SO
2R radical where R is an aryl group as defined above e.g., phenylsulfonyl, and the
like.
[0053] "Biologic" means a therapeutic agent originally derived from living organisms for
the treatment or management of a disease. examples include, but are not limited to,
proteins (recombinant and plasma derived), monoclonal or polyclonal, humanized or
murine antibodies, toxins, hormones, Remicade
®, Refacto
®, Referon-A
®, Factor VIII, Factor VII, Betaseron
®, Epogen
®, Enbrel
®, Interferon beta, Botox
®, Fabrazyme
®, Elspar
®, Cerezyme
®, Myobloc
®, Aldurazyme
®, Verluma
®, Interferon alpha, Humira
®, Aranesp
®, Zevalin
® or OKT3 and the like. Biologics are currently available for the treatment of a variety
of diseases such as cancer, rheumatoid arthritis, and haemophilia.
[0054] "Carboxy" refers to the -C(O)OH radical.
[0055] "Carboxyalkyl" refers to an -(alkylene)-C(O)OH radical e.g., carboxymethyl, carboxyethyl,
and the like.
[0056] "Cycloalkyl" refers to a monovalent saturated or partially unsaturated, monocyclic
ring containing 3, 4, 5, 6, 7, or 8 ring carbon atoms e.g., cyclopropyl, cyclobutyl,
cyclopentyl, cyclohexyl, cyclohexenyl, 2,5-cyclohexadienyl, and the like.
[0057] "Cycloalkyloxy" refers to a radical -O-R where R is cycloalkyl group as defined above,
e.g cyclopropyloxy, cyclohexyloxy, cyclopentyloxy, and the like.
[0058] "Cycloalkylalkyl" refers to an -(alkylene)-R radical where R is cycloalkyl as defined
above e.g., cyclopropylmethyl, cyclobutylethyl, cyclobutylmethyl, and the like
[0059] "Cycloalkylene" refers to a divalent saturated or partially unsaturated monocyclic
ring containing 3, 4, 5, 6, 7, or 8 ring carbon atoms. For example, the instance wherein
"R
1 and R
2 together with the carbon atom to which both R
1 and R
2 are attached form cycloalkylene" includes, but is not limited to, the following:

and the like.
[0060] "Disubstituted amino" refers to a -NRR' radical where R is alkyl, aryl, aralkyl,
heteroaryl, heteroaralkyl, or heterocyclyl and R' is alkyl, aryl, aralkyl, heteroaryl,
heteroaralkyl, cycloalkyl, heterocyclyl, cycloalkylalkyl, hydroxyalkyl, alkoxyalkyl,
or acyl as defined herein. Representative examples include, but are not limited to,
dimethylamino, methylphenylamino, benzylmethylamino, acetylmethylamino, and the like.
[0061] "Disease" specifically includes any unhealthy condition of an animal or part thereof
and includes an unhealthy condition that may be caused by, or incident to, medical
or veterinary therapy applied to that animal, i.e., the "side effects" of such therapy.
[0062] "Deleterious immune response" means an immune response that prevents effective treatment
of a patient or causes disease in a patient. As an example, dosing a patient with
a murine antibody either as a therapy or a diagnostic agent causes the production
of human antimouse antibodies that prevent or interfere with subsequent treatments.
The incidence of antibody formation versus pure murine monoclonal can exceed 70%.
(
see Khazaeli, M. B. et al. J. Immunother. 1994, 15 , pp 42-52;
Dillman R. O. et al. Cancer Biother. 1994, 9, pp 17-28; and
Reinsberg, J. Hybridoma. 1995,14, pp 205-208). Additional examples of known agents that suffer from deleterious immune responses
are blood-clotting factors such as factor VIII. When administered to hemophilia A
patients, factor VIII restores the ability of the blood to clot. Although factor VIII
is a human protein, it still elicits an immune response in hemophiliacs as endogenous
factor VIII is not present in their blood and thus it appears as a foreign antigen
to the immune system. Approximately 29-33% of new patients will produce antibodies
that bind and neutralize the therapeutically administered factor VIII (
see Lusher J. M. Semin Thromb Hemost. 2002, 28(3), pp 273-276). These neutralizing antibodies require the administration of larger amounts of factor
VIII in order to maintain normal blood clotting parameters; an expensive regimen of
treatment in order to induce immune tolerance (
see Briet E et al. Adv. Exp. Med. Bio. 2001, 489, pp 89-97). Another immunogenic example is adenoviral vectors. Retroviral therapy remains experimental
and is of limited utility. One reason is that the application of a therapeutic virus
generates an immune response capable of blocking any subsequent administration of
the same or similar virus
(see Yiping Yang et al. J. of Virology. 1995, 69, pp 2004-2015). This ensures that retroviral therapies must be based on the transient expression
of a protein or the direct incorporation of viral sequence into the host genome. Directed
research has identified multiple viral neutralizing epitopes recognized by host antibodies
(see Hanne, Gahery-Segard et al. J. of Virology 1998. 72, pp 2388-2397) suggesting that viral modifications will not be sufficient to overcome this obstacle.
This invention will enable a process whereby an adenoviral therapy will have utility
for repeated application. Another example of an immunogenic agent that elicits neutralizing
antibodies is the well-known cosmetic agent Botox. Botulin toxin protein, is purified
from the fermentation of
Clostridium botulinum. As a therapeutic agent, it is used for muscle disorders such as cervical dystonia
in addition to cosmetic application. After repeated exposure patients generate neutralizing
antibodies to the toxin that results in reduced efficacy
(see Birklein F. et al. Ann Neurol. 2002, 52, pp 68-73 and
Rollnik, J. D. et al. Neurol. Clin. Neurophysiol. 2001, 2001(3), pp 2-4). A "deleterious immune response" also encompasses diseases caused by therapeutic
agents. A specific example of this is the immune response to therapy with recombinant
human erythropoietin (EPO). Erythropoeitin is used to stimulate the growth or red
cells and restore red blood cell counts in patients who have undergone chemotherapy
or dialysis. A small percentage of patients develop antibodies to EPO and subsequently
are unresponsive to both therapeutically administered EPO and their own endogenous
EPO (
see Casadevall, N. et al., NEJM. 2002, 346, pp 469-475). They contract a disorder, pure red cell aplasia, in which red blood cell production
is severely diminished
(see Gershon S. K. et. al. NEJM. 2002, 346, pp 1584-1586). This complication of EPO therapy is lethal if untreated. Another specific example
is the murine antibody, OKT3 (a.k.a., Orthoclone) a monoclonal antibody directed towards
CD-3 domain of activated T-cells. In clinical trials 20-40% of patients administered
OKT3 produce antibodies versus the therapy. These antibodies besides neutralizing
the therapy also stimulate a strong host immune reaction. The immune reaction is severe
enough that patients with high titers of human antimouse antibodies are specifically
restricted from taking the drug (
see Orthoclone package label). A final example is a human antibody therapeutic. Humira
® is a monoclonal antibody directed against TNF and is used to treat rheumatoid arthritis
patients. When taken alone ∼12% of patients develop neutralizing antibodies. In addition,
a small percentage of patients given the drug also contract a systemic lupus erthematosus-like
condition that is an IgG-mediated immune response induced by the therapeutic agent
(
see Humira package label). Another example of "deleterious immune response" is a host
reaction to small molecule drugs. It is known to those skilled in the art that certain
chemical structures will conjugate with host proteins to stimulate immune recognition
(see
Ju. C. et al. 2002. Current Drug Metabolism 3, pp 367-377 and
Kimber I. et al. 2002, Toxicologic Pathology 30, pp 54-58.) A substantial portion of this host reactions are IgG mediated. Specific "deleterious
immune responses" that are IgG mediated and include: hemolytic anemia, Steven-Johnson
syndrome and drug induced Lupus.
[0063] "Halo" refers to fluoro, chloro, bromo or iodo.
[0064] "Haloalkyl" refers to alkyl as defined above substituted by one or more, preferably
1, 2, 3, 4, or 5 "halo" atoms, as such terms are defined above. Haloalkyl includes
monohaloalkyl, dihaloalkyl, trihaloalkyl, perhaloalkyl and the like e.g. chloromethyl,
dichloromethyl, difluoromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, perfluoroethyl,
2,2,2-trifluoro-1,1-dichloroethyl, and the like.
[0065] "Haloalkylene" refers to alkylene radical as defined above where one to six hydrogen
atoms are replaced by chlorine or fluorine atoms(s), preferably one or two hydrogens
are replaced with fluoroine or chlorine atoms, more preferably two atoms on the same
carbon of the alkylene chain are replaced with fluorine atoms e.g. dichloromethylene,
difluoromethylene, 1,2-difluoroethylene, and the like.
[0066] "Haloalkoxy" refers to a -OR radical where R is a haloalkyl group as defined above
e.g., trifluoromethoxy, 2,2,2-trifluoroethoxy, difluoromethoxy, and the like.
[0067] "Heteroaryl" as a group or part of a group denotes an aromatic monocyclic or multicyclic
moiety of 5, 6, 7, 8, 9, or 10 ring atoms in which one or more, preferably one, two,
or three, of the ring atom(s) is(are) selected from nitrogen, oxygen or sulfur, the
remaining ring atoms being carbon. Representative heteroaryl rings include, but are
not limited to, pyrrolyl, furanyl, thienyl, oxazolyl, isoxazolyl, thiazolyl, imidazolyl,
triazolyl, tetrazolyl, pyridinyl, pyrimidinyl, pyrazinyl, pyridazinyl, indolyl, benzofuranyl,
benzothienyl, benzimidazolyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl,
pyrazolyl, and the like.
[0068] "Heteroaralkyl" refers to a -(alkylene)-R radical where R is heteroaryl as defined
above e.g., pyridinylmethyl, 1- or 2-furanylethyl, imidazolylmethyl, and the like.
[0069] "Heteroaryloxyalkyl" refers to an-(alkylene)-OR radical where R is heteroaryl as
defined above e.g., furanyloxymethyl, 2-, or 3-indolyloxyethyl, and the like.
[0070] "Heteroaryloxy" refers to an -OR radical where R is heteroaryl as defined above.
[0071] "Heteroaralkyloxy" refers to an -OR radical where R is heteroaralkyl as defined above.
[0072] "Heteroarylsulfonyl" refers to an -SO
2R radical where R is an heteroaryl group as defined above e.g., pyridinylsulfonyl,
and the like.
[0073] "Heterocyclyl" refers to a saturated or partially unsaturated, mono or bicyclic radical
of 4, 5 or 6 carbon ring atoms wherein one or more, preferably one, two, or three
of the ring carbon atoms are replaced by a heteroatom selected from -N=, -N-, -O-,
-S-, -SO-, or -S(O)
2-and further wherein one or two ring atoms are optionally replaced by a keto (-CO-)
group. The heterocyclyl ring is optionally fused to aryl or heteroaryl ring as defined
herein. Representative examples include, but are not limited to, imidazolidinyl, morpholinyl,
thiomorpholinyl, thiomorpholino-1-oxide, thiomorpholino-1,1-dioxide, tetrahydropyranyl,
tetrahydrothiopyranyl, 1-oxo-tetrahydrothiopyranyl, 1,1-dioxotetrathiopyranyl, indolinyl,
piperazinyl, piperidyl, pyrrolidinyl, pyrrolinyl, quinuclidinyl, and the like.
[0074] "Heterocyclylalkyl" refers to a -(alkylene)-heterocyclyl radical as defined in this
Application. Representative examples include, but are not limited to, imidazolidin-1-ylmethyl,
morpholin-4-ylmethyl, thiomorpholin-4-ylmethyl, thiomorpholin-4-ylmethyl-1-oxide,
indolinylethyl, piperazinylmethyl or ethyl, piperidylmethyl or ethyl, pyrrolidinylmethyl
or ethyl, and the like.
[0075] "Heterocyclyloxy" refers to an -OR radical where R is heterocyclyl as defined above
e.g., piperidinyloxy, tetrahydrofuranyloxy, and the like.
[0076] "Heterocyclylsulfonyl" refers to an -SO
2R radical where R is an heterocyclyl group as defined above e.g., piperidinylsulfonyl,
piperazinylsulfonyl, and the like.
[0077] "Heterocyclylalkylene" refers to a divalent heterocyclyl group, as defined in this
Application, e.g., the instance wherein R
1 and R
2 together with the carbon atom to which both R
1 and R
2 are attached form heterocyclylalkylene" includes, but is not limited to, the following:

in which R is a substituent defined in the Summary of the Invention
[0078] "Hydroxy" means -OH radical.
[0079] "Hydroxyalkyl" means a linear monovalent hydrocarbon radical of 1, 2, 3, 4, 5, or
6 carbon atoms or a branched monovalent hydrocarbon radical of 3, 4, 5, 6 carbons
substituted with one or two hydroxy groups, provided that if two hydroxy groups are
present they are not both on the same carbon atom. Representative examples include,
but are not limited to, hydroxymethyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl,
1-(hydroxymethyl)-2-methylpropyl, 2-hydroxybutyl, 3-hydroxybutyl, 4-hydroxybutyl,
2,3-dihydroxypropyl, 1-(hydroxymethyl)-2-hydroxyethyl, 2,3-dihydroxybutyl, 3,4-dihydroxybutyl
and 2-(hydroxymethyl)-3-hydroxypropyl, preferably 2-hydroxyethyl, 2,3-dihydroxypropyl,
and 1-(hydroxymethyl)-2-hydroxyethyl.
[0080] "Isomers" mean compounds having identical molecular formulae but differ in the nature
or sequence of bonding of their atoms or in the arrangement of their atoms in space.
Isomers that differ in the arrangement of their atoms in space are termed "stereoisomers".
Stereoisomers that are not mirror images of one another are termed "diastereomers"
and stereoisomers that are nonsuperimposable mirror images are termed "enantiomers"
or sometimes "optical isomers". A carbon atom bonded to four nonidentical substituents
is termed a "chiral center". A compound with one chiral center has two enantiomeric
forms of opposite chirality is termed a "racemic mixture". A compound that has more
than one chiral center has 2
n-1 enantiomeric pairs, where
n is the number of chiral centers. Compounds with more than one chiral center may exist
as either an individual diastereomer or as a mixture of diastereomers, termed a "diastereomeric
mixture". When one chiral center is present a stereoisomer may be characterized by
the absolute configuration of that chiral center. Absolute configuration refers to
the arrangement in space of the substituents attached to the chiral center. Enantiomers
are characterized by the absolute configuration of their chiral centers and described
by the
R- and
S-sequencing rules of Cahn, Ingold and Prelog. Conventions for stereochemical nomenclature,
methods for the determination of stereochemistry and the separation of stereoisomers
are well known in the art (e.g., see "
Advanced Organic Chemistry", 4th edition, March, Jerry, John Wiley & Sons, New York,
1992). It is understood that the names and illustration used in this Application to describe
compounds of Formula (I) are meant to be encompassed all possible stereoisomers.
[0081] "Keto" means a -C(O) radical.
[0082] "Monosubstituted amino" refers to an -NHR radical where R is alkyl, aryl, aralkyl,
heteroaryl, heteroaralkyl, cycloalkyl, cycloalkylalkyl, hydroxyalkyl, alkoxyalkyl,
or acyl as defined herein. Representative examples include, but are not limited to,
methylamino, phenylamino, benzylamino, cycloalkylmethylamino, acetylamino, trifluoroacetyl,
and the like.
[0083] "Nitro" means -NO
2 radical.
[0084] "Optional" or "optionally" or "may be" means that the subsequently described event
or circumstance may or may not occur, and that the description includes instances
where the event or circumstance occurs and instances in which it does not. For example,
the phrase "wherein the aromatic ring in R
a is optionally substituted with one or two substituents independently selected from
alkyl" means that the aromatic ring may or may not be substituted with alkyl in order
to fall within the scope of the invention.
[0085] The present invention also includes
N-oxide derivatives of a compound of Formula I.
N-oxide derivative mean a compound of Formula I in which a nitrogen atom is in an oxidized
state (i.e., N→O) e.g., pyridine
N-oxide, and which possess the desired pharmacological activity.
[0086] "Pathology" of a disease means the essential nature, causes and development of the
disease as well as the structural and functional changes that result from the disease
processes.
[0087] "Pharmaceutically acceptable" means that which is useful in preparing a pharmaceutical
composition that is generally safe, non-toxic and neither biologically nor otherwise
undesirable and includes that which is acceptable for veterinary use as well as human
pharmaceutical use.
[0088] "Pharmaceutically acceptable salts" means salts of compounds of Formula I which are
pharmaceutically acceptable, as defined above, and which possess the desired pharmacological
activity. Such salts include acid addition salts formed with inorganic acids such
as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid,
and the like; or with organic acids such as acetic acid, propionic acid, hexanoic
acid, heptanoic acid, cyclopentanepropionic acid, glycolic acid, pyruvic acid, lactic
acid, malonic acid, succinic acid, malic acid, maleic acid, fumaric acid, tartaric
acid, citric acid, benzoic acid,
o-(4-hydroxybenzoyl)benzoic acid, cinnamic acid, mandelic acid, methylsulfonic acid,
ethanesulfonic acid, 1,2-ethanedisulfonic acid, 2-hydroxy-ethanesulfonic acid, benzenesulfonic
acid, p-chlorobenzenesulfonic acid, 2-naphthalenesulfonic acid,
p-toluenesulfonic acid, camphorsulfonic acid, 4-methylbicyclo[2.2.2]oct-2-ene-1-carboxylic
acid, glucoheptonic acid, 4,4'-methylenebis(3-hydroxy-2-ene-1-carboxylic acid), 3-phenylpropionic
acid, trimethylacetic acid, tertiary butylacetic acid, lauryl sulfuric acid, gluconic
acid, glutamic acid, hydroxynaphthoic acid, salicylic acid, stearic acid, muconic
acid and the like.
[0089] Pharmaceutically acceptable salts also include base addition salts which may be formed
when acidic protons present are capable of reacting with inorganic or organic bases.
Acceptable inorganic bases include sodium hydroxide, sodium carbonate, potassium hydroxide,
aluminum hydroxide and calcium hydroxide. Acceptable organic bases include ethanolamine,
diethanolamine, triethanolamine, tromethamine,
N-methylglucamine and the like.
[0090] Prodrugs of a compound of Formula I are described. Prodrug means a compound that
is convertible
in vivo by metabolic means (e.g. by hydrolysis) to a compound of Formula I. For example an
ester of a compound of Formula I containing a hydroxy group may be convertible by
hydrolysis in vivo to the parent molecule. Alternatively an ester of a compound of
Formula I ontaining a carboxy group may be convertible by hydrolysis in vivo to the
parent molecule. Suitable esters of compounds of Formula I containing a hydroxy group,
are for example acetates, citrates, lactates, tartrates, malonates, oxalates, salicylates,
propionates, succinates, fumarates, maleates, methylene-bis-b-hydroxynaphthoates,
gentisates, isethionates, di-
p-toluoyltartrates, methylsulphonates, ethanesulphonates, benzenesulphonates, p-toluenesulphonates,
cyclohexylsulphamates and quinates. Suitable esters of compounds of Formula I containing
a carboxy group, are for example those described by
Leinweber, F.J. Drug Metab. Res., 1987, 18, page 379. An especially useful class of esters of compounds of Formula I containing a hydroxy
group, may be formed from acid moieties selected from those described by
Bundgaard et al., J. Med. Chem., 1989, 32, pp 2503-2507, and include substituted (aminomethyl)-benzoates, for example, dialkylamino-methylbenzoates
in which the two alkyl groups may be joined together and/or interrupted by an oxygen
atom or by an optionally substituted nitrogen atom, e.g. an alkylated nitrogen atom,
more especially (morpholino-methyl)benzoates, e.g. 3- or 4-(morpholinomethyl)-benzoates,
and (4-alkylpiperazin-1-yl)benzoates, e.g. 3- or 4-(4-alkylpiperazin-1-yl)benzoates.
[0092] "Therapeutically effective amount" means that amount which, when administered to
an animal for treating a disease, is sufficient to effect such treatment for the disease.
[0093] "Treatment" or "treating" means any administration of a compound of the present invention
and includes:
[0094] (1) preventing the disease from occurring in an animal which may be predisposed to
the disease but does not yet experience or display the pathology or symptomatology
of the disease,
[0095] (2) inhibiting the disease in an animal that is experiencing or displaying the pathology
or symptomatology of the diseased (i.e., arresting further development of the pathology
and/or symptomatology), or
[0096] (3) ameliorating the disease in an animal that is experiencing or displaying the
pathology or symptomatology of the diseased (i.e., reversing the pathology and/or
symptomatology).
[0097] "Treatment" or "treating" with respect to combination therapy i.e., use with a biologic
means any administration of a compound of the present invention and includes:
[0098] (1) preventing the immune response from occurring in an animal which may be predisposed
to the immune response but does not yet experience or display the pathology or symptomatology
of the immune response,
[0099] (2) inhibiting the immune response in an animal that is experiencing or displaying
the pathology or symptomatology of the immune response (i.e., arresting further development
of the pathology and/or symptomatology), or
[0100] (3) ameliorating the immune response in an animal that is experiencing or displaying
the pathology or symptomatology of the immune response (i.e., reducing in degree or
severity, or extent or duration, the overt manifestations of the immune response or
reversing the pathology and/or symptomatology e.g., reduced binding and presentation
of antigenic peptides by MHC class II molecules, reduced activation of T-cells and
B-cells, reduced humoral and cell-mediated responses and, as appropriate to the particular
immune response, reduced inflammation, congestion, pain, necrosis, reduced loss in
the efficacy of a biologic agent, and the like).
PREFERRED EMBODIMENTS
[0101] Certain compounds of Formula I within the broadest scope set forth in the Summary
of the Invention are preferred. For example:
[0102] One preferred group of compounds of Formula I includes those compounds in which R
1 is optionally substituted aryl, R
4 is A-X-R
8, and Y is oxygen. Within this group, a subgroup includes compounds in which R
2 and R
3 are both hydrogen and E is a covalent bond, particularly where Z is -C(R
5)(R
6)-R
10, in which R
5 and R
6 together with the carbon atom to which they are attached form a cycloalkyl group
of 3-6 carbon atoms, especially where the cycloalkyl group is cyclopropyl, and R
10 is cyano. Preferred among these compounds are those in which R
1 is phenyl substituted by fluoro, A is alkylene of 1-3 carbon atoms optionally substituted
by fluoro, X is a covalent bond or -S(O)
2, and R
8 is heteroarylalkyl or cycloalkyl.
[0103] A second preferred group includes those compounds of Formula I in which E is -CH(R
9)-C(O)-C(O)-NH- and Z is -C(R
5)(R
6)-R
10, in which R
5 and R
6 together with the carbon tom to which they are attached form a cycloalkyl group of
3-6 carbon atoms, particularly where the cycloalkyl group is cyclopropyl, and R
10 is hydrogen. Preferred among these compounds are those in which R
1 is phenyl substituted by fluoro, A is alkylene of 1-3 carbon atoms optionally substituted
by fluoro, X is a covalent bond or -S(O)
2, R
8 is heteroaryl or cycloalkyl, and R
9 is ethyl.
[0104] A third preferred group includes those compounds in which R
2 is R
7-C ≡C-, R
3 is hydrogen, and E is a covalent bond. Within this group preferred compounds include
those compounds in which Z is -C(R
5)(R
6)-R
10, in which R
5 and R
6 together with the carbon atom to which they are attached form a cycloalkyl group
of 3-6 carbon atoms, especially where the cycloalkyl group is cyclopropyl, and R
10 is hydrogen. Within this subgroup are preferred compounds in which R
1 is phenyl substituted by fluoro, thiomethyl, or methylsulfonyl, A is alkylene of
1-3 carbon atoms optionally substituted by fluoro, X is a covalent bond or -S(O)
2, and R
8 is heteroarylalkyl or cycloalkyl, especially where R
7 is methyl.
[0105] Preferred compounds include the following:
[0106] (R)-N-(1-cyanocyclopropyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(pyridin-3-ylmethylsulfonyl)propanamide;
[0107] (S)-N-cyclopropyl-3-((R)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(pyridin-3-ylmethylsulfonyl)propanamido)-2-oxopentanamide;
[0108] (S)-N-cyclopropyl-3-((R)-3-(cyclopropylmethylsulfonyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanamido)-2-oxopentanamide;
[0109] (R)-N-(1-cyanocyclopropyl)-3-(cyclopropylmethylthio)-2-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)propanamide;
[0110] (R)-N-(1-cyanocyclopropyl)-3-(cyclopropylmethylsulfonyl)-2-((S)-1,1-difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-ylamino)propanamide;
[0111] (R)-N-(1-cyanocyclopropyl)-2-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-3-(pyridin-2-ylmethylthio)propanamide;
[0112] (R)-N-(1-cyanocyclopropyl)-2-((S)-1,1-difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-ylamino)-3-(pyridin-2-ylmethylsulfonyl)propanamide;
[0113] (R)-N-(1-cyanocyclopropyl)-3-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-2-((pyridin-3-ylmethylthio)methyl)propanamide;
[0114] (R)-N-(1-cyanocyclopropyl)-3-((S)-1,1-difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-ylamino)-2-((pyridin-3-ylmethylsulfonyl)methyl)propanamide;
[0115] 3-(((R)-3-(1-cyanocyclopropylamino)-2-(((S)-1,1-difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-ylamino)methyl)-3-oxopropylsulfonyl)methyl)pyridine
1-oxide;
[0116] (S)-N-(1-cyanocyclopropyl)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide;
and
[0117] (S)-5-cyclopropyl-N-((S)-1-(cyclopropylamino)-1,2-dioxopentan-3-yl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide.
GENERAL SYNTHETIC SCHEME
[0118] Compounds of this invention can be made by the methods depicted in the reaction schemes
shown below.
[0119] The starting materials and reagents used in preparing these compounds are either
available from commercial suppliers such as Aldrich Chemical Co., (Milwaukee, Wis.),
Bachem (Torrance, Calif.), or Sigma (St. Louis, Mo.) or are prepared by methods known
to those skilled in the art following procedures set forth in references such as
Fieser and Fieser's Reagents for Organic Synthesis, Volumes 1-17 (John Wiley and Sons,
1991);
Rodd's Chemistry of Carbon Compounds, Volumes 1-5 and Supplementals (Elsevier Science
Publishers, 1989);
Organic Reactions, Volumes 1-40 (John Wiley and Sons, 1991),
March's Advanced Organic Chemistry, (John Wiley and Sons, 4th Edition) and
Larock's Comprehensive Organic Transformations (VCH Publishers Inc., 1989).
[0120] These schemes are merely illustrative of some methods by which the compounds of this
invention can be synthesized, and various modifications to these schemes can be made
and will be suggested to one skilled in the art having referred to this disclosure.
[0121] The starting materials and the intermediates of the reaction may be isolated and
purified if desired using conventional techniques, including but not limited to filtration,
distillation, crystallization, chromatography and the like. Such materials may be
characterized using conventional means, including physical constants and spectral
data.
[0122] Unless specified to the contrary, the reactions described herein take place at atmospheric
pressure over a temperature range from about -78 °C to about 150 °C, more preferably
from about 0 °C to about 125 °C and most preferably at about room (or ambient) temperature,
e.g., about 20 °C. In the reactions described hereinafter it may be necessary to protect
reactive functional groups, for example hydroxy, amino, imino, thio or carboxy groups,
where these are desired in the final product, to avoid their unwanted participation
in the reactions. Conventional protecting groups may be used in accordance with standard
practice, for examples see
T.W. Greene and P. G. M. Wuts in "Protective Groups in Organic Chemistry" John Wiley
and Sons, 1999.
[0123] The preparation of compounds of Formula I is shown below.
1) Preparation of a Compound of Formula I in which R2 is Hydrogen, R4 is -A-X-R8, E is a Covalent Bond, and Z is -C(R5)(R6)-R10
[0124] Reaction Scheme I shows a synthesis of a compound of Formula I in which R
2 is hydrogen, R
4 is -A-X-R
8, in which X is S or O and R
8 is as defined above, E is a covalent bond, and Z is
[0125] -C(R
5)(R
6)-R
10, in which R
10 is cyano.

Step 1 - Preparation of a Compound of Formula (2)
[0126] A mixture of a compound of formula (1) in a polar solvent, typically N,N-dimethylformamide,
is added to a metal hydride, typically sodium hydride, dispersed in the same solvent,
at a temperature of about room temperature. To this mixture is added an ester of 2-bromo-2,2-difluoroacetic
acid, preferably ethyl 2-bromo-2,2-difluoroacetate, optionally in the same solvent.
The mixture is stirred for about 2-3 hours at room temperature. When the reaction
is substantially complete, the product of formula (2) is isolated by conventional
means, for example by addition of ethyl acetate, careful addition of water to quench
the reaction, washing with water, and removing the solvent under reduced pressure
to provide a compound of formula (2).
Step 2 - Preparation of a Compound of Formula (3)
[0127] To a mixture of a compound of formula (2) in an inert solvent, typically diethyl
ether, is added a reducing agent, preferably lithium aluminum hydride, at a temperature
of about 0°C. The mixture is then stirred at about room temperature for about 4 hours.
When the reaction is substantially complete, the product of formula (3) is isolated
by conventional means, for example by addition of ethyl acetate to quench the excess
lithium aluminum hydride, followed by methanol and excess hydrochloric acid. Extraction
with an inert solvent, typically ethyl acetate, and removing the solvent under reduced
pressure provides a compound of formula (3).
Steps 3 and 4 - Preparation of a Compound of Formula (6)
[0128] To a mixture of a compound of formula (3) and a hindered base, typically diisopropylethylamine,
in an inert solvent, typically dichloromethane, at a temperature of about -78°C, is
added trifluoromethanesulfonic anhydride. The mixture is then stirred for about 1-3
hours to form a compound of formula (4). To this product is added a mixture of a compound
of formula (5) in an inert solvent, typically dichloromethane, and the temperature
allowed to warm to 0°C. When the reaction is substantially complete, the product of
formula (6) is isolated by conventional means, for example by addition of ethyl acetate,
washing with water, and removing the solvent under reduced pressure provides a compound
of formula (6).
Step 5 - Preparation of a Compound of Formula (7)
[0129] To a mixture of a compound of formula (6) in an inert solvent, typically dichloromethane,
is added trifluoroacetic acid, followed by triethylsilane, at about room temperature.
The mixture is then stirred at about room temperature for about 4 hours, and solvent
removed under reduced pressure. To the residue is added hexanes and aqueous sodium
hydroxide solution, and the mixture extracted with hexanes. To the sodium hydroxide
layer is added a compound of formula R
8-halo, preferably R
8Br, and optionally a phosphine derivative, for example P(CH
2CH
2CO
2H)
3. When the reaction is substantially complete, the product of formula (7) is isolated
by conventional means, for example by addition of ethyl acetate, and washing with
a dilute acid, for example hydrochloric acid, and removing the solvent under reduced
pressure.
Step 6 - Preparation of a Compound of Formula I
[0130] The compound of formula (7) is contacted with a compound of formula (8) in the presence
of reagents suitable for amide formation, for example 1-methyl-3-(3'-dimethylaminopropyl)-carbodiimide
(EDCI) and 1-hydroxybenzotriazole (HOBT), in the presence of a mild base, for example
N-methylmorpholine NMM, in an inert organic solvent, for example dichloromethane.
The reaction is conducted at about room temperature, for about 2-12 hours. When the
reaction is substantially complete, the product of Formula I is isolated by conventional
means, for example by diluting the reaction mixture with an inert organic solvent,
for example ethyl acetate, and washing with aqueous sodium bicarbonate, brine and
drying, to provide a compound of Formula I in which R
2 is hydrogen, R
4 is -A-X-R
8, in which X is S or O and R
8 is as defined above, and E is a covalent bond.
Step 7 - Preparation of a Compound of Formula I where X is SO2
[0131] To prepare a compound of Formula I where X is -SO
2-, the product from Step 6 dissolved in a suitable solvent, for example N-methylpyrrolidine,
is contacted with Oxone in water. Typically the reaction is conducted at about room
temperature.. When the reaction is substantially complete, the product of Formula
I where X is -SO
2- is isolated by conventional means, for example by diluting the reaction mixture
with an inert organic solvent, for example ethyl acetate, and washing with aqueous
sodium bicarbonate, brine and drying, to provide a compound of Formula I in which
R
2 is hydrogen, R
4 is -A-X-R
8, in which X is SO
2 and R
8 is as defined above, and E is a covalent bond.
2) Preparation of a Compound of Formula I in which R2 is Hydrogen, R4 is -A-X-R8, E is -CH(R9)-C(O)-C(O)-NH-, and Z is -C(R5)(R6)-R10
[0132] The compounds of Formula I in which R
2 is hydrogen, R
4 is A-X-R
8, E is -CH(R
9)-C(O)-C(O)-NH-, and Z is -C(R
5)(R
6)R
10, in which R
10 is hydrogen, are prepared as shown in Reaction Scheme II.

Step 1 - Preparation of a Compound of Formula (10)
[0133] The compound of formula (7), prepared as shown in Reaction Scheme I, is contacted
with a compound of formula (9) in the presence of reagents suitable for amide formation,
for example 1-ethyl-3-(3'-dimethylaminopropyl)-carbodiimide (EDCI) and 1-hydroxybenzotriazole
(HOBT), in the presence of a mild base, for example N-methylmorpholine NMM, in an
inert organic solvent, for example dichloromethane. The reaction is conducted at about
room temperature, for about 2-12 hours. When the reaction is substantially complete,
the product of Formula I is isolated by conventional means, for example by diluting
the reaction mixture with an inert organic solvent, for example ethyl acetate, and
washing with aqueous sodium bicarbonate, brine and drying, to provide a compound of
formula (10).
Step 2 - Preparation of a Compound of Formula I
[0134] The compound of formula (10) is is reacted with a mild oxidizing agent, for example
1,1,1-triacetoxy-1,1-dihydro-1,2-benziodoxol-3(1H)-one (Dess Martin periodinanane
Reagent). The reaction is conducted in an inert organic solvent, for example dichloromethane,
for about 1 hour at about room temperature. When the reaction is substantially complete,
the product of Formula I is isolated by conventional means, for example by diluting
the reaction mixture with an inert organic solvent, for example ethyl acetate, and
washing with dilute sodium bicarbonate, water, brine and drying. Removal of the solvent
under reduced pressure provides a compound of Formula I in which R
2 is hydrogen, R
4 is -X-R
8, E is -CH(R
9)-C(O)-C(O)-NH-, and Z is -C(R
5)(R
6)R
10, in which R
10 is hydrogen
2A) Preparation of a Compound of Formula I in which R2 is Hydrogen, R4 is -A-SO2-R8, E is -CH(R9)-C(O)-C(O)-NH-, and Z is -C(R5)(R6)-R10, in which R10 is Hydrogen
[0135] The compounds of Formula I in which R
2 is hydrogen, R
4 is -X-R
8, in which X is - SO
2, E is -CH(R
9)-C(O)-C(O)-, and Z is -C(R
5)(R
6)-R
10, in which R
10 is hydrogen, are prepared as shown in Reaction Scheme IIA.

Step 1 Preparation of a Compound of Formula (10A)
[0136] The compound of (7A), which is a compound of formula (7) in which X is -S-, is reacted
as shown in step 1 in Reaction Scheme II with a compound of formula (9), to give a
compound of formula (10A).
Step 2 Preparation of a Compound of Formula (10B)
[0137] The compound of formula (10A) is dissolved in an amine, typically N-methylmorpholine,
and an aqueous solution of Oxone (potassium peroxymonosulfate) added, and the mixture
stirred at room temperature for about 3 hours. When the reaction is substantially
complete, the product of formula (10B) is isolated by conventional means, and used
in the next reaction with no further purification.
Step 3 Preparation of a Compound of Formula I in which X is -SO2-
[0138] The compound of formula (10B) is then reacted as shown in Reaction Scheme II, step
2, to provide a compound of Formula I in which X is -SO
2-, E is -CH(R
9)-C(O)-C(O)-NH-, and Z is -C(R
5)(R
6)-R
10, in which R
10 is hydrogen.
3) Preparation of a Compound of Formula I in which R2 is R7-C≡C-, R4 is -A-X-R8, E is a Covalent Bond, and Z is -C(R5)(R6)-R10, in which R10 is Cyano
[0139] The compounds of Formula I in which R
2 is R
7-C ≡C-, R
4 is -A-X-R
8, E is a covalent bond, and Z is -C(R
5)(R
6)-R
10, in which R
10 is cyano, are prepared as shown in Reaction Scheme III.

Step 1 - Preparation of a Compound of Formula (11)
[0140] The lithiated alkynyl compound of formula R
7-C ≡C-Li is prepared by contacting an alkynyl compound of formula R
7-C ≡C-H with butyl lithium in an inert solvent, typically tetrahydrofuran, at a temperature
of about -78°C, for about 10 minutes to 2 hours. The compound of formula (2), prepared
for example as shown in Reaction Scheme I, is then added at about -78°C, and the mixture
maintained for that temperature for about 20 minutes, then at -40°C for about 5 hours.
When the reaction is substantially complete, the product of formula (11) is isolated
by conventional means, for example by quenching the reaction, for example by addition
of brine or saturated ammonium chloride, then diluting the reaction mixture with an
inert organic solvent, for example ether, and washing with brine and drying, to provide
a compound of formula (11).
Step 2 - Preparation of a Compound of Formula (12)
[0141] To a solution of a compound of formula (11) in an inert solvent, for example toluene
or dichloromethane, or typically a mixture of toluene and dichloromethane, is added
the Corey catalyst ((S)-1-methyl-3,3-diphenyl-tetrahydro-pyrrolo[1,2-C][1,3,2]oxazaborazole),
at about room temperature. The mixture is cooled to about -60 to about -80°C, and
catecholborane added. The reaction is maintained at this temperature for about 10-24
hours, followed by addition of an aqueous strong acid in an inert solvent, typically
hydrochloric acid in dioxane, followed by aqueous 10% sodium thiosulfate solution.
The mixture is allowed to warm to room temperature. When the reaction is substantially
complete, the product of formula (12) is isolated by conventional means, for example
by quenching the reaction, for example by addition of brine or saturated ammonium
chloride, then diluting the reaction mixture with an inert organic solvent, for example
ether, and washing with brine and drying, to provide a compound of formula (12).
Step 3 - Preparation of a Compound of Formula (14)
[0142] To a mixture of the compound of formula (12) in an inert solvent, typically ether,
at a temperature of about -10 to 10°C, is added sodium hydride. After about 1 hour
trifluoromethanesulfonyl chloride is added, and the mixture stirred for about 1-5
hours to form a compound of formula (13). This solution is cooled to about -78°C,
and then a mixture of a compound of formula (5) and a hindered base, typically diisopropylethylamine,
in an inert solvent, typically dichloromethane, is added, and the temperature allowed
to warm to about 0°C. When the reaction is substantially complete, the product of
formula (14) is isolated by conventional means, typically followed by purification
on a silica gel column.
Step 4 - Preparation of a Compound of Formula (15)
[0143] To a mixture of a compound of formula (14) in an inert solvent, typically dichloromethane,
is added trifluoroacetic acid, followed by triethylsilane, at about room temperature.
The mixture is then stirred at about room temperature for about 4 hours, and solvent
removed under reduced pressure. To the residue is added hexanes and aqueous sodium
hydroxide solution, and the mixture extracted with hexanes. To the sodium hydroxide
layer is added a compound of formula R
8-halo, preferably R
8Br. When the reaction is substantially complete, the product of formula (15) is isolated
by conventional means, for example by addition of ethyl acetate, and washing with
a dilute acid, for example hydrochloric acid, and removing the solvent under reduced
pressure.
Step 5 - Preparation of a Compound of Formula I
[0144] The compound of formula (15) is contacted with a compound of formula (8), for example
aminocyclopropanecarbonitrile, in the presence of reagents suitable for amide formation,
for example 1-ethyl-3-(3'-1-dimethylaminopropyl)-carbodiimide (EDCI) and 1-hydroxybenzotriazole
(HOBT), in the presence of a mild base, for example N-methylmorpholine NMM, in an
inert organic solvent, for example dichloromethane. The reaction is conducted at about
room temperature, for about 2-12 hours. When the reaction is substantially complete,
the product of Formula I is isolated by conventional means, for example by diluting
the reaction mixture with an inert organic solvent, for example ethyl acetate, and
washing with aqueous sodium bicarbonate, brine and drying, to provide a compound of
Formula I in which in which R
2 is R
7-C ≡C-, R
4 is -A-X-R
8, E is a covalent bond, and Z is -C(R
5)(R
6)-R
10, in which R
10 is cyano.
[0145] The compounds of Formula I in which R
2 is cis or trans R
7-CH=CH- may be prepared from intermediates of formula (12a) and (12b), the preparation
of which is shown in Reaction Scheme IIIA.

Preparation of the Compound of Formula (12a)
[0146] In general, an alkyne of formula (12) may be reduced to a trans alkene of formula
(12a) by means well known in the art. For example, by hydrogenation of the compound
of formula (12) using a rhodium complex, for example [RhH
2(OC(O)OH)PPr
i3)
2]. Typically, the reaction is carried out in an inert solvent, for example N,N-dimethylformamide,
at about room temperature. When the reaction is substantially complete, the product
of formula (12a) is isolated by conventional means.
Preparation of the Compound of Formula (12b)
[0147] In general, an alkyne of formula (12) may be reduced to a cis alkene of formula (12b)
by means well known in the art. For example, by hydrogenation of the compound of formula
(12) in the presence of a cobalt catalyst, for example [CoH(CO)(PBu
n3)
3. Typically, the reaction is carried out in an inert solvent, for example N,N-dimethylformamide,
at about room temperature. When the reaction is substantially complete, the product
of formula (12b) is isolated by conventional means.
4) Preparation of a Compound of Formula I in which R2 is Hydrogen, R4 is -A-X-R8, in which A is -CH2-CF2-, X is a Covalent Bond, and R8 is Cycloalkylmethyl, E is a Covalent Bond, and Z is -C(R5)(R6)-R10, in which R10 is Cyano
[0148] The compounds of Formula I in which R
2 is Hydrogen, R
4 is -A-X-R
8, in which A is - CH
2-CF
2-, X is a Covalent Bond, and R
8 is Cycloalkylmethyl, E is a Covalent Bond, and Z is -C(R
5)(R
6-R
10, in which R
10 is cyano, are prepared as shown in Reaction Scheme IV.

Step 1-Preparation of a Compound of Formula (17)
[0149] Typically, triphenylphosphite methiodide is added to a solution of (
S)-2-
tert-butyloxycarbonylamino-3-hydroxypropionic acid methyl ester in a polar solvent, for
example N,N-dimethylformamide, at a temperature of about 0°C. When the reaction is
substantially complete, typically after about 15-60 minutes, the product of formula
(17) is isolated by conventional means.
Step 2 - Preparation of a Compound of Formula (20)
[0150] Zinc dust is suspended in an aqueous acid solution, typically 2M HCl and stirred
vigorously for about 5 minutes, then filtered and washed, typically sequentially with
water, ethanol, and ether. This material is heated under vacuum for several minutes
then allowed to cool to room temperature. The heated/cooling procedure (under vacuum)
is typically repeated twice more, and finally the placed under an inert gas, for example
nitrogen.
[0151] The activated zinc is suspended in a mixture of inert solvents, typically dry benzene
and dry N,N-dimethylacetamide, and treated with 1,2-dibromoethane. This mixture is
gently heated over 1 hour. Trimethylsilyl chlorideis then added, and the mixture maintained
at about room temperature for about 5-60 minutes. When the reaction is substantially
complete, the material thus obtained is used in the next reaction without any further
purification.
[0152] To the mixture of activated zinc obtained is added a solution of (
R)-2-
tert-butyloxycarbonylamino-3-iodopropionic acid methyl ester (the compound of formula (17)
in a mixture of inert solvents, for example benzene and N,N-dimethylacetamide. The
reaction is carried out for about 1-4 hours, and optionally treated with further portions
of trimethylsilyl chloride. Palladium bis trityl dichloride (PdCl
2(PPh
3)
2) is then added in a single portion, followed by a solution of cyclopropylacetyl chloride
(the compound of formula (19)) in an inert solvent, for example benzene. The reaction
was carried out for about 30-60 minutes. When the reaction is substantially complete
the product of formula (20) is isolated by conventional means.
Step 4 - Preparation of a Compound of Formula (21)
[0153] To a compound of formula (20), preferably in the absence of solvent, is added diethylaminosulfur
trifluoride (DAST), and the resulting mixture maintained at about room temperature
for about 5-6 days. When the reaction is substantially complete the product of formula
(21) is isolated by conventional means, and optionally purified by column chromatography.
Step 5 - Preparation of a Compound of Formula (22)
[0154] To a compound of formula (21) in an aqueous solvent, typically tetrahydrofuran/water,
is added an inorganic base, preferably lithium hydroxide, and the mixture maintained
at about room temperature for about 12-24 hours. When the reaction is substantially
complete the free acid is isolated by conventional means, for example acidication
with an organic acid, typically citric acid, and partitioning between a solvent and
water, for example ethyl acetate/water, and removing the solvent under reduced pressure.
The BOC group is then removed by treatment with an acid, typically aqueous hydrochloric
acid in an inert solvent, for example dioxane, to provide the compound of formula
(22) as a hydrochloride salt.
Step 6 - Preparation of a Compound of Formula (23)
[0155] A solution of the difluoroethanol analog of the compound of formula (4) and a hindered
base, typically diisopropylethylamine, in an inert solvent, for example dichloromethane,
is added to a solution of triflic anhydride in an inert solvent, for example dichloromethane,
maintained at about -50 to -80°C. After about 15 minutes, the mixture is allowed to
warm to about room temperature, and a compound of formula (22) as its acid salt is
added along with a hindered base, typically diisopropylethylamine. The mixture is
warmed to about 30-50°C for about 24-72 hours. When the reaction is substantially
complete the product of formula (23) is isolated by conventional means, for example
acidication with an organic acid, typically citric acid, and partitioning between
a solvent and water, for example ethyl acetate/water, and removing the solvent under
reduced pressure.
Step 7 - Preparation of a Compound of Formula I
[0156] To a mixture of a compound of formula (23) and an aminonitrile of formula (8) in
an inert solvent, for example dichloromethane, is added O-(7-azabenzotriazole-1-yl)-N,N,N,N'-tetramethyluronium
hexafluorophosphate (HATU), and the mixture maintained at about room temperature.
To this mixture is added a tertiary base, typically N-methylmorpholine, and the mixture
maintained at about room temperature for about 12-24 hours. When the reaction is substantially
complete the product of Formula I is isolated by conventional means.
5) Preparation of a Compound of Formula I in which R2 is Hydrogen, R4 is -A-X-R8, in which A is -CH2-CF2-, X is a Covalent Bond, and R8 is Cycloalkylmethyl, E is -CH(R9)-C(O)-C(O)-NH-, and Z is -C(R5)(R6)-R10, where R10 is Hydrogen
[0157] The preparation of a compound of Formula I in which R
2 is Hydrogen, R
4 is -A-X-R
8, in which A is -CH
2-CF
2-, X is a Covalent Bond, and R
8 is Cycloalkylmethyl, E is -CH(R
9)-C(O)-C(O)-NH-, and Z is -C(R
5)(R
6)-R
10, in which R
10 is hydrogen, from a compound of formula (23) is shown in Reaction Scheme V.

[0158] The reaction steps are carried out in a manner similar to those shown in Reaction
Scheme II above.
[0159] The N-oxides of compounds of Formula I can be prepared by methods known to those
of ordinary skill in the art. For example, N-oxides can be prepared by treating an
unoxidized form of the compound of Formula I with an oxidizing agent (e.g., trifluoroperacetic
acid, permaleic acid, perbenzoic acid, peracetic acid, meta-chloroperoxybenzoic acid,
or the like) in a suitable inert organic solvent (e.g., a halogenated hydrocarbon
such as dichloromethane) at approximately 0°C. Alternatively, the N-oxides of the
compounds of Formula I can be prepared from the N-oxide of an appropriate starting
material.
[0160] Prodrug derivatives of the compounds of Formula I can be prepared by methods known
to those of ordinary skill in the art (e.g., for further details see
Saulnier et al. (1994), Bioorganic and Medicinal Chemistry Letters, Vol. 4, p. 1985). For example, appropriate prodrugs can be prepared by reacting a non-derivatized
compound of Formula I with a suitable carbamylating agent (e.g., 1,1-acyloxyalkylcarbonochloridate,
para-nitrophenyl carbonate, or the like).
[0162] Compounds of the present invention may be conveniently prepared or formed during
the process of the invention, as solvates (e.g. hydrates). Hydrates of compounds of
the present invention may be conveniently prepared by recrystallisation from an aqueous/organic
solvent mixture, using organic solvents such as dioxin, tetrahydrofuran or methanol.
[0163] Compounds of Formula I can be prepared as their individual stereoisomers by reacting
a racemic mixture of the compound with an optically active resolving agent to form
a pair of diastereoisomeric compounds, separating the diastereomers and recovering
the optically pure enantiomer. While resolution of enantiomers can be carried out
using covalent diasteromeric derivatives of compounds of Formula I, dissociable complexes
are preferred (e.g., crystalline diastereoisomeric salts). Diastereomers have distinct
physical properties (e.g., melting points, boiling points, solubilities, reactivity,
etc.) and can be readily separated by taking advantage of these dissimilarities. The
diastereomers can be separated by chromatography or, preferably, by separation/resolution
techniques based upon differences in solubility. The optically pure enantiomer is
then recovered, along with the resolving agent, by any practical means that would
not result in racemization. A more detailed description of the techniques applicable
to the resolution of stereoisomers of compounds from their racemic mixture can be
found in
Jean Jacques Andre Collet, Samuel H. Wilen, Enantiomers, Racemates and Resolutions,
John Wiley & Sons, Inc. (1981).
Pharmacology and Utility
[0164] The compounds of the invention are inhibitors of cysteine proteases, in particular,
cathepsin S, K, B, and/or F, and accordingly are useful for treating diseases in which
cysteine protease activity contributes to the pathology and/or symptomatology of the
disease. For example, the compounds of the invention are useful in treating autoimmune
disorders, including, but not limited to, juvenile onset diabetes, psoriasis, multiple
sclerosis, pemphigus vulgaris, Graves' disease, myasthenia gravis, systemic lupus
erythemotasus, rheumatoid arthritis and Hashimoto's thyroiditis, allergic disorders,
including, but not limited to, asthma, allogeneic immune responses, including, but
not limited to, organ transplants or tissue grafts and endometriosis.
[0165] Cathepsin S is also implicated in disorders involving excessive elastolysis, such
as chronic obstructive pulmonary disease (e.g., emphysema), bronchiolitis, excessive
airway elastolysis in asthma and bronchitis, pneumonities and cardiovascular disease
such as plaque rupture and atheroma. Cathepsin S is implicated in fibril formation
and, therefore, inhibitors of cathepsins S are of use in treatment of systemic amyloidosis.
[0166] The cysteine protease inhibitory activities of the compounds of Formula I can be
determined by methods known to those of ordinary skill in the art. Suitable
in vitro assays for measuring protease activity and the inhibition thereof by test compounds
are known. Typically, the assay measures protease-induced hydrolysis of a peptide-based
substrate. Details of assays for measuring protease inhibitory activity are set forth
in Biological Examples 1-5,
infra.
Administration and Pharmaceutical Compositions
[0167] In general, compounds of Formula I will be administered in therapeutically effective
amounts via any of the usual and acceptable modes known in the art, either singly
or in combination with one or more therapeutic agents. A therapeutically effective
amount may vary widely depending on the severity of the disease, the age and relative
health of the subject, the potency of the compound used and other factors. For example,
therapeutically effective amounts of a compound of Formula I may range from about
10 micrograms per kilogram body weight (µg/kg) per day to about 20 milligram per kilogram
body weight (mg/kg) per day, typically from about 100 µg/kg/day to about 10 mg/kg/day.
Therefore, a therapeutically effective amount for an 80 kg human patient may range
from about 1 mg/day to about 1.6 g/day, typically from about 1 mg/day to about 100
mg/day. In general, one of ordinary skill in the art, acting in reliance upon personal
knowledge and the disclosure of this Application, will be able to ascertain a therapeutically
effective amount of a compound of Formula I for treating a given disease.
[0168] The compounds of Formula I can be administered as pharmaceutical compositions by
one of the following routes: oral, systemic (e.g., transdermal, intranasal or by suppository)
or parenteral (e.g., intramuscular, intravenous or subcutaneous). Compositions can
take the form of tablets, pills, capsules, semisolids, powders, sustained release
formulations, solutions, suspensions, elixirs, aerosols, or any other appropriate
composition and are comprised of, in general, a compound of Formula I in combination
with at least one pharmaceutically acceptable excipient. Acceptable excipients are
non-toxic, aid administration, and do not adversely affect the therapeutic benefit
of the active ingredient. Such excipient may be any solid, liquid, semisolid or, in
the case of an aerosol composition, gaseous excipient that is generally available
to one of skill in the art. Solid pharmaceutical excipients include starch, cellulose,
talc, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, magnesium
stearate, sodium stearate, glycerol monostearate, sodium chloride, dried skim milk,
and the like. Liquid and semisolid excipients may be selected from water, ethanol,
glycerol, propylene glycol and various oils, including those of petroleum, animal,
vegetable or synthetic origin (e.g., peanut oil, soybean oil, mineral oil, sesame
oil, and the like). Preferred liquid carriers, particularly for injectable solutions,
include water, saline, aqueous dextrose and glycols.
[0169] The amount of a compound of Formula I in the composition may vary widely depending
upon the type of formulation, size of a unit dosage, kind of excipients and other
factors known to those of skill in the art of pharmaceutical sciences. In general,
a composition of a compound of Formula I for treating a given disease will comprise
from 0.01%w to 10%w, preferably 0.3%w to 1%w, of active ingredient with the remainder
being the excipient or excipients. Preferably the pharmaceutical composition is administered
in a single unit dosage form for continuous treatment or in a single unit dosage form
ad libitum when relief of symptoms is specifically required. Representative pharmaceutical
formulations containing a compound of Formula I are described in Example 1 below.
Examples
[0170] The present invention is further exemplified, but not limited by, the following examples
that illustrate the preparation of compounds of Formula I (Examples) and intermediates
(References) according to the invention.
Example 1
Preparation of a Compound of Formula (2)
A. Preparation of a Compound of Formula (2) in which R1 is 4-Fluorophenyl and Y is Oxygen
[0171]

[0172] To a mixture of sodium hydride (60%, 535 mg) in N,N-dimethylformamide (30 ml) at
room temperature was added a solution of 4-fluorophenol (1.5 g) in a small volume
of N,N-dimethylformamide. After 40 minutes ethyl 2-bromo-2,2-difluoroacetate was added
dropwise to the mixture, and the mixture stirred for 3 hours. The reaction mixture
was then diluted with ethyl acetate, washed 3x with aqueous sodium bicarbonate solution,
dried over sodium sulfate, and solvent removed under reduced pressure, to provide
crude ethyl 2,2-difluoro-2-(4-fluorophenoxy)acetate, a compound of formula (2). This
product was chromatographed on silica gel, eluting with ethyl acetate/hexanes 1/40,
to provide pure ethyl 2,2-difluoro-2-(4-fluorophenoxy)acetate, which was used with
no further purification.
1H NMR (CDCl3; 400MHz): δppm 7.05-7.22 (m, 4H); 4.39 (q, 2H), 1.38 (t, 3H)
[0173] B. Similarly, following the procedure of Example 1A, but replacing 4-fluorophenol
with 4-methylthiophenol, ethyl 2,2-difluoro-2-(4-(methylthio)phenoxy)acetate was prepared.
[0174] C. Similarly, following the procedure of Example 1A, but replacing 4-fluorophenol
with other compounds of formula (1), other compounds of formula (2) are prepared.
For example, ethyl 2,2-difluoro-2-(4-(methylsulfonyl)phenoxy)acetate.
Example 2
Preparation of a Compound of Formula (3)
A. Preparation of a Compound of Formula (3) in which R1 is 4-Fluorophenyl and Y is Oxygen
[0175]

[0176] To a solution of ethyl 2,2-difluoro-2-(4-fluorophenoxy)acetate (1.86 g) in diethyl
ether (10 ml) at 0°C was added lithium aluminum hydride (1.0M in diethyl ether, 11.9
ml). After 5 minutes the cooling bath was removed and the mixture stirred at room
temperature for 4 hours. The mixture was then recooled to 0°C, and ethyl acetate added
dropwise, followed by dropwise addition of methanol. The mixture was acidified with
aquesous 1N hydrochloric acid, extracted with ethyl acetate, dried over sodium sulfate,
and solvent removed under reduced pressure, to provide 2,2-difluoro-2-(4-fluorophenoxy)ethanol
as a colorless oil. This product was chromatographed on silica gel, eluting with ethyl
acetate/hexanes 1/5, which yielded crystalline 2,2-difluoro-2-(4-fluorophenoxy)ethanol.
1H NMR (CDC
13; 400MHz): δppm 6.91- 7.12 (m, 4H); 3.90 (t, 2H).
[0177] B. Similarly, following the procedure of Example 2A, but replacing ethyl 2,2-difluoro-2-(4-fluorophenoxy)acetate
with ethyl 2,2-difluoro-2-(4-(methylthio)phenoxy)acetate, 2,2-difluoro-2-(4-(methylthio)phenoxy)ethanol
was prepared.
[0178] C. Similarly, following the procedure of Example 2A, but replacing ethyl 2,2-difluoro-2-(4-fluorophenoxy)acetate
with other compounds of formula (2), other compounds of formula (3) are prepared,
for example 2,2-difluoro-2-(4-(methylsulfonyl)phenoxy)ethanol.
Example 3
Preparation of a Compound of Formula (4)
A. Preparation of a Compound of Formula (4), in which R1 is 4-Fluorophenyl and Y is Oxygen
[0179]

[0180] To a solution of 2,2-difluoro-2-(4-fluorophenoxy)ethanol (1.18 g) and diisopropylethylamine
(3.74 ml) in dichloromethane at -78°C was added trifluoromethanesulfonic anhydride
(1.08 ml) dropwise. After stirring for 4 hours, the solution of 2,2-difluoro-2-(4-fluorophenoxy)ethyl
trifluoromethanesulfonate thus produced was used in the next reaction without any
purification.
[0181] B. Similarly, following the procedure of Example 3A, but replacing 2,2-difluoro-2-(4-fluorophenoxy)ethanol
with 2,2-difluoro-2-(4-(methylthio)phenoxy)ethanol, 2,2-diftuoro-2-(4-(methylthio)phenoxy)ethyl
trifluoromethanesulfonate was prepared.
[0182] C. Similarly, following the procedure of Example 3A, but replacing 2,2-difluoro-2-(4-fluorophenoxy)ethanol
with other compounds of formula (3), other compounds of formula (4) are prepared.
For example 1-(1,1-difluoro-2-(trifluoromethylsulfonyl)ethoxy)-4-(methylsulfonyl)benzene.
Example 4
Preparation of a Compound of Formula (6)
A. Preparation of a Compound of Formula (6) in which R1 is 4-Fluorophenyl, Y is Oxygen, R3 is Hydrogen, A is Methylene, and X is Sulfur
[0183]

[0184] To the product of Example 3 (2,2-difluoro-2-(4-fluorophenoxy)ethyl trifluoromethanesulfonate
in dichloromethane) at -78°C was added S-trityl-L-cysteine (2.23 g), and the mixture
stirred for 1 hour. The temperature was raised to 0°C, and the mixture stirred for
48 hours. The solvent was removed under reduced pressure, the residue diluted with
ethyl acetate, washed with dilute hydrochloric acid (1N), brine, and dried over sodium
sulfate. The solvent was removed under reduced pressure, and the residue chromatogrqphed
on silica gel, eluting with ethyl acetate/hexane 1/2 containing a few drops of acetic
acid, to provide 2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(tritylthio)propanoic
acid (2.08 g).
[0185] B. Similarly, following the procedure of Example 4A, but replacing 2,2-difluoro-2-(4-fluorophenoxy)ethyl
trifluoromethanesulfonate with 2,2-difluoro-2-(4-(methylthio)phenoxy)ethyl trifluoromethanesulfonate,
2-(2,2-difluoro-2-(4-(methylthio)phenoxy)ethylamino)-3-(tritylthio)propanoic acid
was prepared.
[0186] C. Similarly, following the procedure of Example 4A, but replacing 2,2-difluoro-2-(4-fluorophenoxy)ethyl
trifluoromethanesulfonate with with other compounds of formula (4), other compounds
of formula (6) are prepared. For example, 2-(2,2-difluoro-2-(4-(methylsulfonyl)phenoxy)ethylamino)-3-(tritylthio)propanoic
acid.
Example 5
Preparation of a Compound of Formula (7)
A. Preparation of a Compound of Formula (7) in which R1 is 4-Fluorophenyl, Y is Oxygen, R3 is Hydrogen, A is Methylene, X is Sulfur, and R8 is Cycloproplmethyl
[0187]

[0188] To a solution of 2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(tritylthio)propanoic
acid (2.08 g) in dichloromethane (25 ml) was added trifluoroacetic acid (1.2 ml),
followed by triethylsilane (1.27 ml). The mixture was strirred for 5 hours, then solvent
removed under reduced pressure. Hexanes (100 ml) were added, followed by 2N sodium
hydroxide (25 ml), and the mixture stirred. The aqueous layer was separated, washed
with hexanes twice, and the volume reduced under reduced pressure by about half. To
this solution was added 3,3',3"-phosphinetriyltripropanoic acid (65 mg) and cyclopropylmethyl
bromide (261 mg). The mixture was stirred for 90 minutes at room temperature, then
a further 100 mgs of cyclopropylmethyl bromide added. The mixture was stirred overnight,
then diluted with ethyl acetate, washed with 1N hydrochloric acid, the ethyl acetate
layer separated, dried over sodium sulfate, and the solvent removed under reduced
pressure, to provide 3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanoic
acid (520 mg) as a white solid.
[0189] B. Similarly, following the procedure of Example 5A, but replacing 2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(tritylthio)propanoic
acid with 2-(2,2-difluoro-2-(4-(methylthio)phenoxy)ethylamino)-3-(tritylthio)propanoic
acid, 3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-(methylthio)phenoxy)ethylamino)propanoic
acid was prepared.
[0190] C. Similarly, following the procedure of Example 5A, but replacing cyclopropylmethyl
bromide with 3-(chloromethyl)pyridine, 2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(pyridin-3-ylmethylthio)propanoic
acid was prepared.
[0191] D. Similarly, following the procedure of Example 4A, but replacing 2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(tritylthio)propanoic
acid with with other compounds of formula (6), and optionally replacing cyclopropylmethyl
bromide with other compounds of formula R
8-halo, other compounds of formula (7) are prepared. For example, 3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-(methylsulfonyl)phenoxy)ethylamino)propanoic
acid.
Example 6
Preparation of a Compound of Formula I
A. Preparation of a Compound of Formula I in which R1 is 4-Fluorophenyl, R2 is Hydrogen, Y is Oxygen, R3 is Hydrogen, A is Methylene, X is SO2, R8 is Cyclopropylmethyl, E is a Covalent Bond, and Z is-C(R5)(R6)-R10, in which R5 and R6 taken together taken together with the carbon atom to which they are attached are
Cyclopropyl and R10 is Cyano
[0192]

[0193] 3-(Cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanoic
acid (120 mg) and N-methylpyrrolidine (4 ml) were stirred with O-(7-azabenzotriazole-1-yl)-N,N,N,N'-tetramethyluronium
hexafluorophosphate (259 mg) and 1-aminocyclopropanecarbonitrile (40 mg) at room temperature
in the presence of diisopropylethylamine (0.15 ml). After 2 hours Oxone in 4 ml of
water was added, and the mixture stirred for 2 hours. The mixture was diluted with
ethyl acetate, washed with water, dried over sodium sulfate, and the solvent removed
under reduced pressure, to provide a crude product, which was purified by silica gel
column chromatography, eluting with ethyl acetate/hexane mixtures, to provide N-(1-cyanocyclopropyl)-3-(cyclopropylmethylsulfonyl)
2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanamide.
[0194] B. Similarly, following the procedure of Example 6A, but replacing 3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanoic
acid with 2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(pyridin-3-ylmethylthio)propanoic
acid, (R)-N-(1-cyanocyclopropyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(pyridin-3-ylmethylsulfonyl)propanamide
was prepared. MS: [M+1]
+ 483.4.
[0195] C. Similarly, following the procedure of Example 6A, but replacing 3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanoic
acid with 2-(2,2-difluoro-2-(4-(methylthio)phenoxy)ethylamino)-3-(pyridin-3-ylmethylthio)propanoic
acid, N-(1-cyanocyclopropyl)-3-(pyridine-3-ylmethylsulfonyl)-2-(2,2-difluoro-2-(4-(methylsulfonyl)phenoxy)ethylamino)propanamide
is prepared.
[0196] D. Similarly, following the procedure of Example 6A, but replacing 3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanoic
acid with with other compounds of formula (7), other compounds of Formula I in which
R
2 is hydrogen, R
4 is -A-X-R
8, E is a covalent bond, and Z is -C(R
5)(R
6)-R
10 are prepared. For example, 3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-(methylsulfonyl)phenoxy)ethylamino)propanoic
acid.
Example 7
Preparation of a Compound of Formula (10A)
A. Preparation of a Compound of Formula (10A) in which R1 is 4-Fluorophenyl, Y is Oxygen, R3 is Hydrogen, A is Methylene, X is Sulfur, R8 is Cyclopropylmethyl, R5 and R6 taken together with the carbon atom to which they are attached are Cyclopropyl, and
R10 is Hydrogen
[0197]

[0198] A dichloromethane solution of 3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-propanoic
acid (150 mg), a compound of formula (7), prepared as shown above, (5 ml) (3S)-3-amino-N-cyclopropy-2-hydroxypentanamide,
a compound of formula (9), 1-ethyl-3-(3'-dimethylaminopropyl)-carbodimide (122mg),
1-hydroxybenzotriazole (70 mg), and N-methylmorpholine (0.19mL) was stirred at room
temperature for 2 hours. The reaction mixture was then diluted with ethyl acetate
and washed with aqueous sodium bicarbonate solution, and then dried over anhydrous
sodium sulfate. Evaporation to dryness under reduced pressure gave (3S)-N-cyclopropyl-3-(3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-propanamido)-2-hydroxypentanamide
(290 mg).
[0199] B. Similarly, following the procedure of Example 7A, but replacing 3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-propanoic
acid with 2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(pyridin-4-ylmethylthio)propanoic
acid, (3S)-N-cyclopropyl-3-(3-(pyridine-3-ylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-propanamido)-2-hydroxypentanamide
was obtained
[0200] C. Similarly, following the procedure of Example 7A, but replacing 3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-propanoic
acid with other compounds of formula (7A), and optionally replacing (R)-2-amino-N-cyclopropylbutanamide
with other compounds of formula (9), other compounds of formula (10A) are prepared.
For example, (3S)-N-cyclopropyl-3-(3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-(methylsulfonyl)phenoxy)ethylamino)-propanamido)-2-hydroxypentanamide.
Example 8
Preparation of a Compound of Formula (10B)
A. Preparation of a Compound of Formula (10B) in which R1 is 4-Fluorophenyl, Y is Oxygen, R3 is Hydrogen, A is Methylene, X is -SO2-, R8 is Cyclopropylmethyl, R5 and R6 taken together with the carbon atom to which they are attached are Cyclopropyl, and
R10 is Hydrogen
[0201]

[0202] To a solution of (3S)-N-cyclopropyl-3-(3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-propanamido)-2-hydroxypentanamide
(29mg) in N-methylpyrrolidone (5 ml) was added a solution of Oxone (638 mg) in water
(5 ml). The mixture was stirred at room temperature for 3 hours, ethyl acetate added,
wahed with water x3, dried over sodium sulfate, and solvent removed under reduced
pressure, to provide (3S)-N-cyclopropyl-3-(3-(cyclopropylmethylsulfonyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanamido)-2-hydroxypentanamide
(230 mg).
[0203] B. Similarly, following the procedure of Example 8A, but replacing (3S)-N-cyclopropyl-3-(3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-propanamido)-2-hydroxypentanamide
with (3S)-N-cyclopropyl-3-(3-(pyridine-3-ylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-propanamido)-2-hydroxypentanamide,
(3S)-N-cyclopropyl-3-(3-(pyridine-3-ylmethylsulfonyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanamido)-2-hydroxypentanamide
was obtained.
[0204] C. Similarly, following the procedure of Example 8A, but replacing (3S)-N-cyclopropyl-3-(3-(cyclopropylmethylthio)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-propanamido)-2-hydroxypentanamide
with other compounds of formula (10A), other compounds of formula (10B) are prepared.
For example, (3S)-N-cyclopropyl-3-(3-(cyclopropylmethylsulfonyl)-2-(2,2-difluoro-2-(4-(methylsulfonyl)phenoxy)ethylamino)propanamido)-2-hydroxypentanamide.
Example 9
Preparation of a Compound of Formula I
A. Preparation of a Compound of Formula I in which R1 is 4-Fluorophenyl, Y is Oxygen, R2 and R3 are Hydrogen, A is Methylene, X is -SO2-, R8 is Pyridin-3-ylmethylene, E is - CH(R9)-C(O)-C(O)-NH-, in which R9 is Ethyl, and Z is -C(R5)(R6)-R10, in which R5 and R6 taken together with the carbon atom to which they are attached are Cyclopropyl, and
R10 is Hydrogen
[0205]

[0206] (3S)-N-cyclopropyl-3-(3-(pyridine-3-ylmethylsulfonyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanamido)-2-hydroxypentanamide
(230 mg) was dissolved in dichloromethane (10 ml) and N-methylpyrrolidine (1.5 ml),
and treated with the Dess Martin periodinanane reagent (255 mg) for 1 hour at room
temperature. The reaction mixture was then diluted with ethyl acetate, and washed
with dilute sodium bicarbonate solution. A solid precipitated out of the solution,
and was filtered off, and added to the residue obtained by evaporation of the ethyl
acetate layer to dryness under reduced pressure. The product was flash chromatographed
on silica gel, eluting with ethyl acetate/hexane1/1, to provide (S)-N-cyclopropyl-3-((R)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(pyridin-3-ylmethylsulfonyl)propanamido)-2-oxopentanamide
(39 mg). MS: [M+1]
+ 571.3; NMR (DMSOd
6): δppm; 0.6 (m, 4H), 0.9 (t, 3H), 1.6 (m, 1H), 1.85 (m, 1H), 2.8 (m, 1H), 4.0 (m,
1H), 4.8 (d,d, 2H), 5.0 (m, 1H), 7.25 (m, 4H), 7.45 (m, 1H), 7.8 (m, 1H), 8.7 (m,
4H).
[0207] B. Similarly, replacing (3S)-N-cyclopropyl-3-(3-(pyridine-3-ylmethylsulfonyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanamido)-2-hydroxypentanamide
with (3S)-N-cyclopropyl-3-(3-(cyclopropylmethylsulfonyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanamido)-2-hydroxypentanamide,
and following the procedures of Example 9A, (S)-N-cyclopropyl-3-((R)-3-(cyclopropylmethylsulfonyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanamido)-2-oxopentanamide
(31953)was obtained. MS: [M+1]
+ 534.3; NMR (DMSOd
6): δppm; 0.35 (m, 2H), 0.65 (m, 6H), 0.8 (t, 3H), 1.1 (m, 1H), 1.45 (m, 1H), 1.65
(m, 1H), 2.55 (m, 1H), 3.9 (m, 1H), 4.95 (m, 1H), 7.25 (m, 4H), 8.4 (d, 1H), 8.85
(m, 1H).
[0208] C. Similarly, replacing (3S)-N-cyclopropyl-3-(3-(pyridine-3-ylmethylsulfonyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanamido)-2-hydroxypentanamide
with other compounds of formula (10B), and following the procedures of Example 9A,
other compounds of Formula I are prepared. For example, (S)-N-cyclopropyl-3-((R)-2-(2,2-difluoro-2-(4-(methylsulfonyl)phenoxy)ethylamino)-3-(pyridin-3-ylmethylsulfonyl)propanamido)-2-oxopentanamide.
Example 10
Preparation of a Compound of Formula (11)
A. Preparation of a Compound of Formula (11) in which R1 is 4-Methylthiophenyl, Y is Oxygen, and R7 is Methyl
[0209]

[0210] To a solution of prop-1-ynyllithium (0.94 g, prepared by adding n-butyl lithium to
prop-1-yne) in tetrahydrofuran at to -78°C was added a solution of ethyl 2,2-difluoro-2-(4-(methylthio)phenoxy)acetate
(5.36 g) in tetrahydrofuran and boron trifluoride etherate (2.58 ml, 1 equivalent).
The temperature was allowed to warm to -40°C for about 4 hours. Brine was then added
to quench the reaction, and the mixture was diluted with ether at room temperature.
The organic layer was separated, dried over sodium sulfate, and the solvent removed
under reduced pressure, to provide 1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-one.
[0211] B. Similarly, following the procedure of Example 10A, but optionally replacing prop-1-ynyllithium
with other compounds of formula R
7-C ≡C-Li, and optionally replacing ethyl 2,2-difluoro-2-(4-(methylthio)phenoxy)acetate
with other compounds of formula (2), other compounds of formula (11) are prepared.
For example, 1,1-difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-one.
Example 11
Preparation of a Compounds of Formula (12)
A Preparation of a Compound of Formula (12) in which R1 is 4-Methylthiophenyl, Y is Oxygen, and R7 is Methyl
[0212]

[0213] To a solution of 1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-one (1.6 g) in
a mixture of dichloromethane (10 ml) and toluene (10 ml) was added Corey catalyst
((S)-1-methyl-3,3-diphenyl-tetrahydro-pyrrolo[1,2-C][1,3,2]oxazaborazole, 0.62 ml).
The mixture was cooled to -78°C, and catecholborane (0.89 g) added. The reaction mixture
was stirred overnight at -78°C, and then the reaction was quenched by the addition
of hydrochloric acid in dioxane and water, followed by aqueous 10% sodium thiosulfate
solution. Ether was added, and the organic layer washed with brine, the organic layer
separated, solvent removed under reduced pressure, to provide (S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ol.
[0214] B. Similarly, following the procedure of Example 11A, but replacing 1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-one
with other compounds of formula (11), other compounds of formula (12) are prepared.
Example 12
Preparation of a Compounds of Formula (14)
A Preparation of a Compound of Formula (14) in which R1 is 4-Methylthiophenyl, Y is Oxygen, R7 is Methyl, R3 is Hydrogen, A is Methylene, X is Sulfur, and Tr is Trityl
[0215]

[0216] To a solution of (S)-1,1-difluom-1-(4-(methylthio)phenoxy)pent-3-yn-2-ol (1.58 g)
in ether at 0°C was added sodium hydride (292 mg of 60%). The mixture was stirred
for 1 hour, then trifluoromethanesulfonyl chloride (1.53 g) added. The mixture was
stirred for 1 hour, to form the triflate derivative of (S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ol.
This solution was cooled to -78°C, and a mixture of diisopropylethylamine and the
trityl derivative of 2-amino-3-mercaptopropanoic acid (1.85 g) in dichloromethane
was added dropwise. The reaction mixture was warmed to 0°C, and ethyl acetate added,
washed with water, brine, dried over sodium sulfate, and the solvent removed, to provide
the trityl derivative of (R)-2-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-3-mercaptopropanoic
acid.
[0217] B. Similarly, following the procedure of Example 12A, but replacing (S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ol
with other compounds of formula (12), other compounds of formula (14) are prepared
Example 13
Preparation of a Compound of Formula (15)
A Preparation of a Compound of Formula (15) in which R1 is 4-Methylthiophenyl, Y is Oxygen, R7 is Methyl, R3 is Hydrogen, A is Methylene, X is Sulfur, and R8 is Pyridin-2-ylmethylene
[0218]

[0219] To a solution of the trityl derivative of (R)-2-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-3-mercaptopropanoic
acid (1.47 g) in dichloromethane (1.5 ml) was added trifluoroacetic acid (0.73 ml)
and triethylsilane (0.75 ml). The mixture was then stirred at room temperature for
4 hours, and solvent removed under reduced pressure. To the residue is added hexanes,
P(CH
2CH
2CO
2H)
3 (68 mg), and aqueous sodium hydroxide solution (12 ml, 1N), and the mixture extracted
with hexanes. To this sodium hydroxide layer was added 3-(chloromethyl)pyridine (125
mg), and the mixture stirred for 2 hours at 40°C. Ethyl acetate was added, the mixture
washed with dilute hydrochloric acid, water, brine, and the solvent removed under
reduced pressure to provide (R)-2-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-3-(pyridin-3-ylmethylthio)propanoic
acid. MS: [M+1]
+ 453.2
[0220] B Similarly, following the procedure of Example 13A, but replacing 2 (chloromethyl)pyridine
with cyclopropylmethylbromide, (R)-3-(cyclopropylmethylthio)-2-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)propanoic
acid was prepared.
[0221] C. Similarly, following the procedure of Example 13A, but optionally replacing (R)-2-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-3-mercaptopropanoic
acid with other compounds of formula (13), and optionally replacing 2-(chloromethyl)pyridine
with other compounds of formula R
8Halide, other compounds of formula (15) are prepared.
Example 14
Preparation of a Compound of Formula I
A Preparation of a Compound of Formula I in which R1 is 4-Methylthiophenyl, R2 is Prop-1-ynyl, Y is Oxygen, R7 is Methyl, R3 is Hydrogen, A is Methylene, X is Sulfur, R8 is Pyridin-2-ylmethylene, and Z is -C(R5)(R6)-R10; in which R5 and R6 when taken together with the carbon atom to which they are attached represent Cyclopropyl,
and R10 is Cyano
[0222]

[0223] To a stirred mixture of 3-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-2-((pyridin-2-yhnethylthio)methyl)propanoic
acid (312 mg) and 1-aminocyclopropanecarbonitrile hydrochloride (82 mg) in N,N-dimethylformamide
(3 ml), O-(7-azabenzotriazole-1-yl)-N,N,N,N'-tetramethyluronium hexafluorophosphate
(259 mg) and diisopropylethylamine (0.36 ml) was added. After stirring overnight at
room temperature, the reaction mixture was diluted with ethyl acetate and washed with
water, saturated aqueous sodium bicarbonate solution, and brine. After drying over
sodium sulfate, the solvent was evaporated and the residue was purified by flash chromatography,
eluting with ethyl acetate/hexanes (1/1), to give (R)-N-(1-cyanocyclopropyl)-2-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-3-(pyridin-2-ylmethylthio)propanamide
(235 mg). MS: [M+1]
+ 517.3
[0224] B. Similarly, following the procedure of Example 14A, but replacing 3-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-2-((pyridin-2-ylmethylthio)methyl)propanoic
acid with 3-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-2-((cyclopropylmethylmethylthio)methyl)propanoic
acid, (R)-N-(1-cyanocyclopropyl)-3-(cyclopropylmethylthio)-2-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)propanamide
was prepared.
MS: [M+1]
+ 480.2
[0225] C. Similarly, following the procedure of Example 14A, but replacing 3-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-2-((pyridin-2-ylmethylthio)methyl)propanoic
acid with 3-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-2-((pyridin-3-ylmethylthio)methyl)propanoic
acid, (R)-N-(1-cyanocyclopropyl)-3-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-2-((pyridin-3-yhnethylthio)methyl)propanamide
was prepared.
MS: [M+1]
+ 517.2
[0226] D. Similarly, following the procedure of Example 14A, but optionally replacing 3-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-2-((pyridin-2-ylmethylthio)methyl)propanoic
acid with other compounds of formula (15), and optionally replacing 1-aminocyclopropanecarbonitrile
hydrochloride with other aminonitriles of formula (8) selected from the group consisting
of 2-amino-2-methylpropanenitrile, 1-aminocyclobutanecarbonitrile, or 1-aminocyclopentanecarbonitrile,
all of which are commercially available, the following compounds are made:
[0227] (S)-N-(2-cyanopropan-2-yl)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide;
[0228] (2S)-N-(1-cyanocyclopropyl)-5-cyclopropyl-2-(1,1-difluoro-1-(4-fluorophenoxy)pent-3-yn-2-ylamino)-4,4-difluoropentanamide;
[0229] (2S)-N-(2-cyanopropan-2-yl)-5-cyclopropyl-2-(1,1-difluoro-1-(4-fluorophenoxy)pent-3-yn-2-ylamino)-4,4-difluoropentanamide;
[0230] (2S)-N-(1-cyanocyclobutyl)-5-cyclopropyl-2-(1,1-difluoro-1-(4-fluorophenoxy)pent-3-yn-2-ylamino)-4,4-difluoropentanamide;
and
[0231] (2S)-N-(1-cyanocyclopentyl)-5-cyclopropyl-2-(1,1-difluoro-1-(4-fluorophenoxy)pent-3-yn-2-ylamino)-4,4-difluoropentanamide.
[0232] D. Similarly, following the procedure of Example 14A, but replacing 3-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-2-((pyridin-2-ylmethylthio)methyl)propanoic
acid with other compounds of formula (15), other compounds of Formula I are prepared.
Example 15
Preparation of a Compound of Formula I
A Preparation of a Compound of Formula I in which R1 is 4-Methylsulfonylphenyl, R2 is Prop-1-ynyl, Y is Oxygen, R7 is Methyl, R3 is Hydrogen, A is Methylene, X is -SO2-, R8 is Pyridin-2-ylmethylene, and Z is -C(R5)(R6)-R10; in which R5 and R6 when taken together with the carbon atom to which they are attached represent Cyclopropyl,
and R10 is Cyano
[0233]

[0234] A solution of (R)-N-(1-cyanocyclopropyl)-2-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-3-(pyridin-2-ylmethylthio)propanamide
(235 mg) in N-methylpyrrolidine (5.5 ml) was added a solution of Oxone (905 mg) in
water (5 ml). After stirring for 3 hours at 45 °C the solvent was evaporated under
reduced pressure, and the residue was partitioned between dichloromethane (15 ml)
and water (15 ml). The organic phase was separated, and the aqueous solution was extracted
with dichloromethane. The combined organic layers were washed with brine and dried
over sodium sulfate. After removal of the solvent under reduced pressure, the crude
was purified by preparative TLC, using ethyl acetate/hexanes (1/1) as mobile phase
to give (R)-N-(1-cyanocyclopropyl)-2-((S)-1,1-difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-ylamino)-3-(pyridin-2-ylmethylsulfonyl)propanamide
(105 mg). MS: [M+1]
+ 581.2
[0235] B. Similarly, following the procedure of Example 15A, but replacing 1-((R)-3-((S)-1,1-difluoro-1-(4-(methylthio)-phenoxy)pent-3-yn-2-ylamino)-2-oxo-4-(pyridin-2-ylmethylthio)butyl)cyclopropanecarbonitrile
with (R)-N-(1-cyanocyclopropyl)-3-(cyclopropylmethylthio)-2-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)propanamide,
(R)-N-(1-cyanocyclopropyl)-3-(cyclopropylmethylsulfonyl)-2-((S)-1,1-difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-ylamino)propanamide
was prepared. MS: [M+1]
+ 544.3
[0236] C. Similarly, following the procedure of Example 15A, but replacing 1-((R)-3-((S)-1,1-difluoro-1-(4-(methylthio)-phenoxy)pent-3-yn-2-ylamino)-2-oxo-4-(pyridin-2-ylmethylthio)butyl)cyclopropanecarbonitrile
with (R)-N-(1-cyanocyclopropyl)-3-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-2-((Pyridin-3-ylmethylthio)methyl)propanamide,
1-((R)-3-((S)-1,1-difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-ylamino)-2-oxo-4-(pyridin-3-ylmethylsulfonyl)butyl)cyclopropanecarbonitrile
was prepared. MS: [M+1]
+ 581.1
[0237] D. Similarly, following the procedure of Example 15A, but replacing N-(1-cyanocyclopropyl)-3-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-2-((cyclopropylmethylthio)methyl)-propanamide
with other compouynds of Formula I in which X is sulfur, other compounds of Formula
I in which X is -SO
2 are prepared. For example:
[0238] E. (2S)-N-(1-cyanocyclopropyl)-5-cyclopropyl-2-(1,1-difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-ylamino)-4,4-difluoropentanamide.
Example 16
Preparation of 1-aminocyclopropanecarbonitrile hydrochloride
[0239]

Step 1
[0240] A mixture ofbenzophenone imine (25 g, 0.138 mol, Aldrich) and aminoacetonitrile hydrochloride
(25 g, 0.270 mol, Lancaster) in dichloromethane (1000 ml) was stirred in a 2L Erlenmeyer
flask under nitrogen at room temperature for 5 days. The reaction mixture was filtered
to remove the precipitated ammonium chloride and the filtrate was evaporated to dryness
in vacuo. The resulting residue was dissolved in ether (400 ml) washed with water (200 ml)
and brine. After drying over magnesium sulfate the solution was evaporated to give
(benzhydrylideneamino)-acetonitrile (47.89 g).
Step 2
[0241] A solution of sodium hydroxide (91 g, 2.275 mol) in water (91 ml) in a 2L flask was
cooled on ice under nitrogen and then treated with benzyl triethyl ammonium chloride
(2.0 g, 0.0088 mol, Aldrich ) and (benzhydrylideneamino)acetonitrile (47.89 g) in
toluene (100 ml). 1,2-Dibromoethane (23 ml, 122.4 mmol, Aldrich) was then added dropwise
over 25 min, to the reaction mixture with mechanical stirring and cooling to maintain
the internal temperature near +10°C. The reaction mixture was then stirred vigorously
for 24 h at room temperature and then poured into ice water and extracted with toluene.
The combined extracts were washed with brine and then treated with MgSO4 and Norite.
After filtering, toluene was removed by rotary evaporation to give an oil (67 g).
The residue was dissolved in boiling hexane (400 ml), treated with Norite and filtered
hot and allowed to cool. A dark oil separated and which was removed by pipet (~2 ml).
Scratching induced crystallization in the remaining solution which was cooled on ice
for 2 h. Light yellow crystals were collected by filtration and washed with cold hexane
to give 1-(benzhydrylideneamino)cyclopropanecarbonitrile (30.56 g).
Step 3
[0242] A mixture of 1-(benzhydrylideneamino)cyclopropanecarbonitrile (30.56 g, 0.124 mol)
in concentrated HCl (12 ml) in water (100 ml) and ether (100 ml) was stirred at room
temperature for 15 h. The ether layer was discarded and the aqueous layer was washed
with ether. The aqueous layer was then freeze dried to give the title compound as
a tan powder (13.51 g).
Example 17
Preparation of (R)-methyl 2-(tert-butoxycarbonylamino)-3-iodopropanoate (17)
[0243]

[0244] Triphenylphosphite methiodide (
Fieser and Fieser, Reagents for Organic Synthesis, Vol. 4, p557; 340g, 753 mmol, 1.4 equiv.) was added in one portion to a solution of (
S)-2-
tert-butyloxycarbonylamino-3-hydroxypropionic acid methyl ester (118g, 538 mmol) in dry
N,N-dimethylformamide (1.1L) at 0°C. After 30 minutes at 0°C solid sodium bicarbonate
(270g) was added followed by water (1.1L). The resulting mixture was stirred vigorously
for 15 minutes and then extracted with 1:1 diethylether/hexanes (3 x 800mL). The combined
organic extracts were washed with 0.5M sodium hydroxide (5 x 1L) and brine (2 x 1L),
dried over magnesium sulfate, filtered, and the filtrate concentrated under reduced
pressure. The resulting orange oil was loaded onto a SiO
2 plug (2" x 7") and eluted with 5% EtOAc/hexanes to afford (R)-methyl 2-(tert-butoxycarbonylamino)-3-iodopropanoate
as a pinkish oil, which solidified (118.5g, 67%)
1H NMR (CDC13; 400MHz): δppm 5.32 (m, 1H), 4.51 (m, 1H), 3.81 (s, 3H), 3.58 (m, 2H),
1.45 (s, 9H).
Example 18
Preparation of (R)-(2-(tert-butoxycarbonylamino)-3-methoxy-3-oxopropyl)zinc(II) iodide (18)
[0245]

[0246] Zinc dust (<10 micron, 94g, 1.44mol), 4 equiv.) was suspended in 2M hydrochloric
acid and stirred vigorously for 5 minutes. After filtration the Zn was sequentially
washed with water, ethanol, and diethylether. This material was transferred to a 3L
flask, placed under high vacuum (0. 1mmHg) and heated externally with a heat gun for
several minutes, then allowed to cool to room temperature. The heated/cooling procedure
(under vacuum) was repeated twice more, and then the vessel was purged with nitrogen.
[0247] The zinc was suspended in dry benzene (1.44L) and dry N,N-dimethylacetamide (96mL)
and treated with 1,2-dibromoethane (3.1mL, 10mol%). This mixture was subject to gentle
external heating until the formation of small bubbles of gas was observed, and this
procedure repeated several times over 1 hour. Trimethylsilylchloride (2.3mL, 5mol%)
was then added and the mixture stirred at room temperature for 30 minutes.
[0248] To this mixture of activated zinc was added dropwise a solution of (
R)-2-
tert-butyloxycarbonylamino-3-iodopropionic acid methyl ester (118.5g, 360mmol) in dry benzene
(144mL) and dry N,N-dimethylacetamide (10mL). On complete addition the reaction was
stirred for 2 hours, treated with a further portion of trimethylsilyl chloride (2.3mL),
and stirred for an additional 30minutes. This product of formula (18), (R)-(2-(tert-butoxycarbonylamino)-3-methoxy-3-oxopropyl)zinc(II)
iodide, was used in the next step with no further purification.
Example 19
Preparation of (S)-methvl 2-(tert-butoxycarbonylamino)-5-cyclopropyl-4-oxopentanoate
(20)
[0249]

[0250] A. To the mixture obtained in Example 18 (the compound of formula (18)) PdCl
2(PPh
3)
2 (12.6g, 5mol%) was added in a single portion, followed by dropwise addition of a
solution of cyclopropylacetyl chloride (1 equiv.) in dry benzene (144mL). On complete
addition the reaction mixture was stirred for 45 minutes, then treated with 2M hydrochloric
acid (1.7L), stirred for 10 minutes, then filtered through celite, eluting with diethylether
(1.7L). The layers were separated, the aqueous layer extracted with diethylether (1.25L),
and the combined organic extracts washed with water (1.25L), brine (1.25L), dried
over magnesium sulfate, filtered, and the filtrate concentrated under reduced pressure.
[0251] Purification of the residue by column chromatography (SiO
2, gradient elution 0% to 20% ethyl aeetate/Hexanes, 10% steps) gave (S)-methyl 2-(tert-butoxycarbonylamino)-5-cyclopropyl-4-oxopentanoate
(R
f 0.18; 25% EtOAc/hexanes) as a dark oil, which also contained some residual metal
solids that was removed by filtration of an Et
2O solution through celite (85.5g, 83%).
[0252] 1H NMR (CDCl3; 400MHz): δppm 5.43 (m, 1H); 4.43 (m, 1H), 3.68 (s, 3H), 3.15 (m, 1H),
2.92 (m, 1H), 2.22 (m, 2H), 1.40 (s, 9H), 0.88 (m, 1H), 0.5 (m, 2H), 0.08 (m, 2H).
[0253] B. Similarly, following the procedure of Example 19A, replacing cyclopropylacetyl
chloride with 2-phenylacetyl chloride, (S)-methyl 2-(tert-butoxycarbonylamino)-4-oxo-5-phenylpentanoate
is prepared.
[0254] Similarly, replacing cyclopropylacetyl chloride with 2-(4-fluorophenyl)acetyl chloride,
(S)-methyl 2-(tert-butoxycarbonylamino)-5-(4-fluorophenyl)-4-oxopentanoate is prepared.
[0255] Similarly, replacing cyclopropylacetyl chloride with 2-(pyridin-3-yl)acetyl chloride,
(S)-methyl 2-(tert-butoxycarbonylamino)-4-oxo-5-(pyridin-3-yl)pentanoate is prepared.
Example 20
Preparation of (S)-methyl 2-(tert-butoxycarbonylamino)-5-cyclopropyl-4,4-difluoropentanoate
(21)
[0256]

[0257] A. To neat (S)-methyl 2-(tert-butoxycarbonylamino)-5-cyclopropyl-4-oxopentanoate
(53g, 185 mmol) was added diethylaminosulfur trifluoride (DAST) (48mL, 370 mmol, 2
equiv.) and the resulting dark, viscous mixture stirred at room temperature for approximately
135 hours. After dilution with dichloromethane (500mL) the mixture was poured into
2M sodium hydroxide (1L), the aqueous phase separated, and extracted with methylene
chloride (300mL). The combined organic extracts were washed with water (500mL), brine
(500mL), dried over magnesium sulfate, filtered, and the filtrate concentrated under
reduced pressure. The residue was purified by column chromatography to give (S)-methyl
2-(tert-butoxycarbonylamino)-5-cyclopropyl-4,4-difluoropentanoate as a dark oil (19.3g,
34%). Unreacted starting material (17.5g, 33%) was also recovered.
1H NMR (CDCl3; 400MHz): δppm 5.02 (m, 1H); 4.36 (m, 1H), 3.59 (s, 3H), 2.28 (m, 2H),
1.62 (m, 1H), 2.22 (m, 2H), 1.27 (s, 9H), 0.65 (m, 1H), 0.38 (m, 2H), 0.02 (m, 2H).
[0258] B. Similarly, following the procedure of Example 20A, replacing (S)-methyl 2-(tert-butoxycarbonylamino)-5-cyclopropyl-4-oxopentanoate
with (S)-methyl 2-(tert-butoxycarbonylamino)-4-oxo-5-phenylpentanoate, (S)-methyl
2-(tert-butoxycarbonylamino)-5-(4-fluorophenyl)-4-oxopentanoate, or (S)-methyl 2-(tert-butoxycarbonylamino)-4-oxo-5-(pyridin-3-yl)pentanoate,
the following compounds of formula (21) are prepared:
(S)-methyl 2-(tert-butoxycarbonylamino)-4,4-difluoro-5-phenylpentanoate;
(S)-methyl 2-(tert-butoxycarbonylamino)-4,4-difluoro-5-(4-fluorophenyl)pentanoate;
and
(S)-methyl 2-(tert-butoxycarbonylamino)-4,4-difluoro-5-(pyridin-3-yl)pentanoate.
Example 21
Preparation of (S)-2-amino-5-cyclopropyl-4,4-difluoropentanoic acid hydrochloride
(22)
[0259]

[0260] A. To (S)-methyl 2-(tert-butoxycarbonylamino)-5-cyclopropyl-4,4-difluoropentanoate
(2.0g, 6.507mmol) in water (20ml) and tetrahydrofuran (5ml) was added lithium hydroxide
(0.47g, 19.51mmol), and the mixture stirred overnight at ambient temperature. The
product was acidified with citric acid (5g), extracted into ethyl acetate ( 250ml),
and the organic layer separated, dried over magnesium sulfate, and filtered through
a small pad of silica. The solvent was evaporated under reduced pressure to yield
1.6g of an orange oil. This oil was dissolved in dichloromethene (5ml) and 4M hydrochloric
acid in dioxane (16.25ml) was added, and the mixture stirred for 4 hours. The solvents
were evaporated to dryness, and the resulting solid triturated with diethylether to
give 1.07g( 71.8%) of (S)-2-amino-5-cyclopropyl-4,4-difluoropentanoic acid hydrochloride
as a buff colored solid.
[0261] 1H NMR (CDCl3; 400MHz): δppm 8.42 (bs, 3H); 4.08 (m, 1H), 3.25 (bs, 1H), 2.58 (m, 2H),
1.82 (m, 2H), 1.4 (1H), 0.75 (m, 1H), 0.48 (m, 2H), 0.18 (m, 2H).
[0262] B. Similarly, following the procedure of Example 21A, replacing (S)-methyl 2-(tert-butoxycarbonylamino)-5-cyclopropyl-4,4-difluoropentanoate
with (S)-methyl 2-(tert-butoxycarbonylamino)-4,4-difluoro-5-phenylpentanoate, (S)-2-amino-4,4-difluoro-5-phenylpentanoic
acid hydrochloride is prepared.
[0263] Similarly, following the procedure of Example 21A, replacing (S)-methyl 2-(tert-butoxycarbonylamino)-5-cyclopropyl-4,4-difluoropentanoate
with (S)-methyl 2-(tert-butoxycarbonylamino)-4,4-difluoro-5-(4-fluorophenyl)pentanoate,
(S)-2-amino-4,4-difluoro-5-(4-fluorophenyl)pentanoic acid hydrochloride is prepared.
[0264] Similarly, following the procedure of Example 21A, replacing (S)-methyl 2-(tert-butoxycarbonylamino)-5-cyclopropyl-4,4-difluoropentanoate
with (S)-methyl 2-(tert-butoxycarbonylamino)-4,4-difluoro-5-(pyridin-3-yl)pentanoate,
(S)-2-amino-4,4-difluoro-5-(pyridin-3-yl)pentanoic acid hydrochloride is prepared.
Example 22
Preparation of a Compound of Formula (23)
Preparation of a Compound of Formula (23) in which R1 is 4-Fluorophenyl and Y is Oxygen
[0265]

[0266] A. 1,1-Difluoro-1-(4-fluorophenoxy)-ethanol (0.84g, 4.35mmol) and diisopropylethylamine
(0.84g, 6.53mmol, 1.5eq) was dissolved in dichloromethane (10ml)), and added to a
solution of triflic anhydride (1.29g , 4.57mmol, 1.05eq) in dichloromethane (15ml)
at -78°C. The mixture was stirred for 15 minutes, and then allowed to warm to room
temperature. To this product was added (S)-2-amino-5-cyclopropyl-4,4-difluoropentanoic
acid hydrochloride (1.00g, 4.35mmol) and diisopropylethylamine (2.25g, 17.40mmol,
4.0eq) and the mixture heated to 40°C for 48 hours. The solvent was evaporated under
reduced pressure, and the residue partitioned between aqueous citric acid (10.0g in
250ml water) and ethyl acetate (250ml). The organic layer was separated and dried
over magnesium sulfate, and the solvent evaporated from the filtrate under reduced
pressure to give (S)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanoic
acid as an off-white solid, which was washed with diisopropyl ether, filtered off,
and dried. Yield 410mg (25.6%)
1H NMR (CDCl3; 400MHz): δppm 7.22 (m, 4H); 3.52-3.05 (m, 3H), 2.48 (m, 2H), 1.91 (m,
2H), 1.24 (m, 1H), 0.8 (m, 1H), 0.46 (m, 2H), 0.12 (m, 2H). LC/MS: retention time;
t = 3.24 min Mass: (M+H)
+ 368; Mass: (M-H)- 366.
B. Preparation of other Compounds of Formula (23), varying R1 and Y
[0267] Similarly, following the procedure of Example 22A, but replacing 1,1-difluoro-1-(4-fluorophenoxy)-ethanol
with (S)-2-amino-4,4-difluoro-5-phenylpentanoic acid hydrochloride, (S)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoro-5-phenylpentanoic
acid is prepared.
[0268] Similarly, following the procedure of Example 22A, but replacing 1,1-difluoro-1-(4-fluorophenoxy)-ethanol
with (S)-2-amino-4,4-difluoro-5-(4-fluorophenyl)pentanoic acid hydrochloride, (S)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoro-5-(4-fluorophenyl)pentanoic
acid is prepared.
[0269] Similarly, following the procedure of Example 22A, but replacing 1,1-difluoro-1-(4-fluorophenoxy)-ethanol
with (S)-2-amino-4,4-difluoro-5-(pyridin-3-yl)pentanoic acid hydrochloride, (S)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino-4,4-difluoro-5-(pyridin-3-yl)pentanoic
acid is prepared.
C. Preparation of a Compound of Formula (23), varying R1 and Y
[0270] Similarly, following the procedure of Example 22A, but optionally replacing 1,1-difluoro-1-(4-fluorophenoxy)-ethanol
with other compounds of formula (4), other compounds of formula (23) are prepared.
Example 23
Preparation of a Compound of Formula I
Preparation of a Compound of Formula I in which R1 is 4-Fluorophenyl, Y is Oxygen, R2 and R3 are Hydrogen, R4 is -A-X-R8, in which A is -CH2-CF2, X is a Covalent Bond, and R8 is Cyclopropylmethyl, E is a Covalent Bond, and Z is 1-Cyanocyclopropyl
[0271]

[0272] A. To a solution of (S)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanoic
acid (200mg, 0.54mmol) and 1-aminocyclopropanecarbonitrile hydrochloride (65mg,0.54mmol)
in dichloromethane was added O-(7-azabenzotriazole-1-yl)-N,N,N,N'-tetramethyluronium
hexafluorophosphate (HATU) (228mg, 0.60mmol, 1.1eq), and the mixture was stirred for
5 minutes. N-Methylmorpholine (220mg,2.18mmol,4.0eq) was them added, and stirred at
room temperature overnight. To the reaction mixture was added aqueous potassium carbonate
(200ml)) and the product was extracted into ethyl acetate (200ml)). The organic layer
was dried over magnesium sulate, filtered through a small pad of silica, and the filtrate
evaporated under reduced pressure. The residue was chromatographed on silica gel,
eluting with 2:1 hexane/ethyl acetate. The product was isolated as 100mg of a yellow
oil. Trituration with hexane afforded 84mg (36%) of (S)-N-(1-cyanocyclopropyl)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide
as a white solid.
1H NMR (d6-DMSO; 400MHz): δppm 8.97 (s, 1H), 7.25 (m, 4H), 3.41 (m, 1H), 3.20 (m, 1H),
3.05 (m, 1H), 2.70 (m, 1H), 2.25 (m, 2H), 1.85 (m, 2H), 1.47 (m, 2H), 1.22 (m, 2H),
0.8 (m, 1H), 0.45 (m, 2H), 0.12 (m, 2H). LC/MS: retention time; t = 4.53 min Mass:
(M+H)
+ 432; Mass: (M-H)
- 430.
B. Preparation of other Compounds of Formula I in which R2 and R3 are Hydrogen, R4 is -A-X-R8, in which A is -CH2-CF2, X is a Covalent Bond, R8 is Cyclopropylmethyl, E is a Covalent Bond, and Z is 1-Cyanocyclopropyl, varying R1 and Y
[0273] Similarly, following the procedure of Example 23A, but replacing 1-aminocyclopropanecarbonitrile
hydrochloride with a compound of formula (8) selected from 2-amino-2-methylpropanenitrile,
1-aminocyclobutanecarbonitrile, and 1-aminocyclopentanecarbonitrile, all of which
are commercially available, and optionally replacing (S)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanoic
acid with other compounds of formula (23), the following compounds are made:
[0274] (S)-N-(2-cyanopropan-2-yl)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide;
[0275] (S)-N-(2-cyanopropan-2-yl)-5-cyclopropyl-2-(2,2-difluoro-2-(4-(methylthio)phenoxy)ethylamino)-4,4-difluoropentanamide
;
[0276] (S)-N-(1-cyanocyclobutyl)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide;
[0277] (S)-N-(1-cyanocyclobutyl)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)4,4-difluoropentanamide;
[0278] (S)-N-(1-cyanocyclopentyl)-5-cyclopropyl-2-(2,2-difluoro-2-(4-methylthiophenoxy)ethylamino)-4,4-difluoropentanamide;
[0279] (S)-N-cyclopropyl-3-((S)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamido)-2-oxohexanamide;
[0280] (S)-N-cyclopropyl-3-((S)-5-cyclopropyl-2-(2,2-difluoro-2-(4-methylthiophenoxy)ethylamino)-4,4-difluoropentanamido)-2-oxohexanamide;
[0281] (S)-N-((S)-1-cyclobutyl-4-(cyclopropylamino)-3,4-dioxobutan-2-yl)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide;
[0282] (S)-N-((S)-1-cyclobutyl-4-(cyclopropylamino)-3,4-dioxobutan-2-yl)-5-cyclopropyl-2-(2,2-difluoro-2-(4-methylthiophenoxy)ethylamino)-4,4-difluoropentanamide.
[0283] (S)-N-(1-cyanocyclopropyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoro-5-phenylpentanamide;
[0284] (S)-N-(1-cyanocyclopropyl)-2-(2,2-difluoro-2-(4-methylthiophenoxy)ethylamino)-4,4-difluoro-5-phenylpentanamide
[0285] (S)-N-(1-cyanocyclopropyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoro-5-(4-fluorophenyl)pentanamide;
[0286] (S)-N-(1-cyanocyclopropyl)-2-(2,2-difluoro-2-(4-methylthiophenoxy)ethylamino)-4,4-difluoro-5-(4-fluorophenyl)pentanamide;
[0287] (S)-N-(1-cyanocyclopropyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoro-5-(pyridin-3-yl)pentanamide;
[0288] (S)-N-(1-cyanocyclopropyl)-2-(2,2-difluoro-2-(4-methylthiophenoxy)ethylamino)-4,4-difluoro-5-(pyridin-3-yl)pentanamide;
[0289] (S)-N-(2-cyanopropan-2-yl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoro-5-(4-fluorophenyl)pentanamide;
[0290] (S)-N-(1-cyanocyclobutyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoro-5-(4-fluorophenyl)pentanamide;
and
[0291] (S)-N-(1-cyanocyclopentyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoro-5-(4-fluorophenyl)pentanamide.
C. Preparation of other Compounds of Formula I in which R2 and R3 are Hydrogen, R4 is -A-X-R8, in which A is -CH2CF2, X is a Covalent Bond, R8 is Cyclopropylmethyl, and E is a Covalent Bond, and Z is 1-Cyanocyclopropyl, varying
R1 and Y
[0292] Similarly, following the procedure of Example 23A, but replacing (S)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanoic
acid with other compounds of formula (23), other compounds of Formula I are prepared.
Example 24
Preparation of a Compound of Formula (24)
Preparation of a Compound of Formula (24) in which R1 is 4-Fluorophenyl and Y is Oxygen
[0293]

[0294] A. To a mixture of (S)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanoic
acid (200mg, 0.54mmol) and (3S)-3-amino-N-cyclopropyl-2-hydroxypentanamide hydrochloride
(114mg, 0.54mmol) in dichloromethane (12ml) was added O-(7-azabenzotriazole-1-yl)-N,N,N,N'-tetramethyluronium
hexafluorophosphate (HATU, (228mg, 0.60mmol, 1.1eq), and the mixture was stirred for
5 minutes before the addition of N-methylmorpholine (220mg, 218mmol, 4.0eq). After
stirring overnight at room temperature the product was partitioned between aqueous
citric acid (10g in 250ml) and ethyl acetate (250ml). The organic layer was separated,
washed with brine, dried over magnesium sulphate, filtered, and solvent evaporated
from the filtrate to give 200mg of (2S)-5-cyclopropyl-N-((3S)-1-(cyclopropylamino)-2-hydroxy-1-oxopentan-3-yl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide
as a pale yellow semi-solid.
1H NMR (d6-DMSO; 400MHz): δppm 7.82-7.60 (m, 2H), 7.42 (m, 4H), 5.58 (m, 1H), 3.95
(m, 1H), 3.85 (m, 1H), 3.44 (m, 1H), 3.20 (m, 1H), 3.00 (m, 1H), 2.62 (m, 2H), 2.35
-2.00 (m, 2H) 1.90 (m, 2H), 1.55 (m, 1H), 1.35 (m), 0.8 (m, 4H), 0.60-0.40 (m, 6H),
0.12 (m, 2H). LC/MS: retention time; t = 4.36 min Mass: (M+H)
+ 522; Mass: (M-H)
- 520.
B. Preparation of Compounds of Formula (24), varying R1 and Y
[0295] Similarly, following the procedure of Example 24A, but replacing (S)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanoic
acid with other compounds of formula (23), other compounds of formula (24) are prepared.
Example 25
Preparation of a Compound of Formula I
A. Preparation of a Compound of Formula I in which R1 is 4-Fluorophenyl, Y is Oxygen, R2 and R3 are Hydrogen, R4 is -A-X-R8, in which A is -CH2-CF2, X is a Covalent Bond, R8 is Cyclopropylmethyl, E is -CH(R9)-C(O)-C(O)-NH-, in which R9 is Ethyl, and R5 and R6 taken together are Cyclopropyl and R10 is Hydrogen
[0296]

[0297] To a solution of (2S)-5-cyclopropyl-N-((3S)-1-(cyclopropylamino)-2-hydroxy-1-oxopentan-3-yl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide
(190mg, 0.36mmol) in N-methylpyrrolidine (4ml) was added Dess-Martin periodinane reaebt
(216mg, 0.51mmol, 1.4eq). The mixture was stirred for 4 hours at room temperature,
then added to saturated aqueous sodium bicarbonate (50ml) containing sodium thiosulfate
(1.5g). The mixture was stirred for 1hour, filtered, the solid material washed with
water, then dried in a vacuum oven at 40°C using phosphorus pentoxide as a drying
agent, yielding (S)-5-cyclopropyl-N-((S)-1-(cyclopropylamino)-1,2-dioxopentan-3-yl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide
144mg (76%)
[0298] 1H NMR (d6-DMSO; 400MHz): δppm 8.65 (1H), 8.38 (1H), 7.35 (m, 4H), 4.90 (m, 1H), 3.48
(m, 1H), 3.22 (m, 1H), 3.05 (m, 1H), 2.72 (m, 1H), 2.65 (m, 1H), 2.35 -2.00 (m), 1.55
(m, 1H), 1.35 (m), 0.90 - 0.42 (m, 10H), 0.60 - 0.40 (m, 6H), 0.12 (m, 2H). LC/MS:
retention time; t = 20.01 min Mass: (M+H)
+ 520.
B: Preparation of Compounds of Formula I varying R1and Y
[0299] Similarly, following the procedure of Example 25A, but replacing (2S)-5-cyclopropyl-N-((3S)-1-(cyclopropylamino)-2-hydroxy-1-oxopentan-3-yl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide
with other compounds of formula (24), other compounds of Formula I are prepared. For
example:
[0300] (S)-N-cyclopropyl-3-((S)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamido)-2-oxohexanamide;
[0301] (S)-N-((S)-1-cyclobutyl-4-(cyclopropylamino)-3,4-dioxobutan-2-yl)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide;
[0302] (S)-N-cyclopropyl-3-((S)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoro-5-(4-fluorophenyl)pentanamido)-2-oxohexanamide;
and
[0303] (S)-N-((S)-1-(cyclopropylamino)-1,2-dioxopentan-3-yl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoro-5-(4-fluorophenyl)pentanamide.
Biological Examples
EXAMPLE 1
Cathepsin B Assay
[0304] Solutions of test compounds in varying concentrations were prepared in 10 µL of dimethyl
sulfoxide (DMSO) and then diluted into assay buffer (40 µL, comprising:
N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES), 50 mM (pH 6); polyoxyethylenesorbitan
monolaurate, 0.05%; and dithiothreitol (DTT), 2.5 mM). Human cathepsin B (0.025 pMoles
in 25 µL of assay buffer) was added to the dilutions. The assay solutions were mixed
for 5-10 seconds on a shaker plate, covered and incubated for 30 min at room temperature.
Z-FR-AMC (20 nMoles in 25 µL of assay buffer) was added to the assay solutions and
hydrolysis was followed spectrophotometrically at (λ 460 nm) for 5 min. Apparent inhibition
constants (K
i) were calculated from the enzyme progress curves using standard mathematical models.
[0305] Compounds of the invention were tested by the above-described assay and observed
to exhibit cathepsin B inhibitory activity.
EXAMPLE 2
Cathepsin K Assay
[0306] Solutions of test compounds in varying concentrations were prepared in 10 µL of dimethyl
sulfoxide (DMSO) and then diluted into assay buffer (40 µL, comprising: MES, 50 mM
(pH 5.5); EDTA, 2.5 mM; and DTT, 2.5 mM). Human cathepsin K (0.0906 pMoles in 25 µL
of assay buffer) was added to the dilutions. The assay solutions were mixed for 5-10
seconds on a shaker plate, covered and incubated for 30 min at room temperature. Z-Phe-Arg-AMC
(4 nMoles in 25 µL of assay buffer) was added to the assay solutions and hydrolysis
was followed spectrophotometrically at (λ 460 nm) for 5 min. Apparent inhibition constants
(K
i) were calculated from the enzyme progress curves using standard mathematical models.
[0307] Compounds of the invention were tested by the above-described assay and observed
to exhibit cathepsin K inhibitory activity.
EXAMPLE 3
Cathepsin L Assay
[0308] Solutions of test compounds in varying concentrations were prepared in 10 µL of dimethyl
sulfoxide (DMSO) and then diluted into assay buffer (40 µL, comprising: MES, 50 mM
(pH 5.5); EDTA, 2.5 mM; and DTT, 2.5 mM). Human cathepsin L (0.05 pMoles in 25 µL
of assay buffer) was added to the dilutions. The assay solutions were mixed for 5-10
seconds on a shaker plate, covered and incubated for 30 min at room temperature. Z-Phe-Arg-AMC
(1 nMoles in 25 µL of assay buffer) was added to the assay solutions and hydrolysis
was followed spectrophotometrically at (λ 460 nm) for 5 min. Apparent inhibition constants
(K
i) were calculated from the enzyme progress curves using standard mathematical models.
[0309] Compounds of the invention were tested by the above-described assay and observed
to exhibit cathepsin L inhibitory activity.
EXAMPLE 4
Cathepsin S Assay
[0310] Solutions of test compounds in varying concentrations were prepared in 10 µL of dimethyl
sulfoxide (DMSO) and then diluted into assay buffer (40 µL, comprising: MES, 50 mM
(pH 6.5); EDTA, 2.5 mM; and NaCl, 100 mM); β-mercaptoethanol, 2.5 mM; and BSA, 0.00%.
Human cathepsin S (0.05 pMoles in 25 µL of assay buffer) was added to the dilutions.
The assay solutions were mixed for 5-10 seconds on a shaker plate, covered and incubated
for 30 min at room temperature. Z-Val-Val-Arg-AMC (4 nMoles in 25 µL of assay buffer
containing 10% DMSO) was added to the assay solutions and hydrolysis was followed
spectrophotometrically (at λ, 460 nm) for 5 min. Apparent inhibition constants (K
i) were calculated from the enzyme progress curves using standard mathematical models.
[0311] Compounds of the invention were tested by the above-described assay and observed
to exhibit cathepsin S inhibitory activity.
EXAMPLE 5
Cathepsin F Assay
[0312] Solutions of test compounds in varying concentrations were prepared in 10 µL of dimethyl
sulfoxide (DMSO) and then diluted into assay buffer (40 µL, comprising: MES, 50 mM
(pH 6.5); EDTA, 2.5 mM; and NaCl, 100 mM); DTT, 2.5 mM; and BSA, 0.01 %. Human cathepsin
F (0.1 pMoles in 25 µL of assay buffer) was added to the dilutions. The assay solutions
were mixed for 5-10 seconds on a shaker plate, covered and incubated for 30 min at
room temperature. Z-Phe-Arg-AMC (2 nMoles in 25 µL of assay buffer containing 10%
DMSO) was added to the assay solutions and hydrolysis was followed spectrophotometrically
(at λ 460 nm) for 5 min. Apparent inhibition constants (K
i) were calculated from the enzyme progress curves using standard mathematical models.
[0313] Compounds of the invention were tested by the above-described assay and observed
to exhibit cathepsin F inhibitory activity.
RESULTS
| Compound |
CATB (Ki) (M) |
CATF (Ki) (M) |
CATL (Ki) (M) |
CATS (Ki) (M) |
CATV (Ki) (M) |
| A |
+ |
+ |
+ |
+++ |
++ |
| B |
+++ |
++ |
+++ |
+++ |
+++ |
| C |
+++ |
+ |
+ |
++ |
+ |
| D |
+ |
+ |
+ |
+++ |
++ |
| E |
+ |
+ |
+ |
+++ |
++ |
| F |
+ |
+ |
+ |
+++ |
+++ |
| G |
+ |
+ |
+ |
+++ |
++ |
| H |
+ |
+ |
+ |
+++ |
+++ |
| I |
+ |
+ |
+ |
+++ |
+++ |
| J |
+++ |
++ |
++ |
+++ |
+++ |
| K |
++ |
|
+++ |
+++ |
+++ |
| L |
+ |
|
+ |
++ |
+ |
+ indicates a Ki of more than 1 microM;
++ indicates a Ki of less than 1 microM;
+++ indicates a Ki of less than 100 nM.
A. (R)-N-(1-cyanocyclopropyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(pyridin-3-ylmethylsulfonyl)propanamide;
B. (S)-N-cyclopropyl-3-((R)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-3-(pyridin-3-ylmethylsulfonyl)propanamido)-2-oxopentanamide;
C. (R)-N-(1-cyanocyclopropyl)-3-(cyclopropylmethylthio)-2-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)propanamide;
D. (R)-N-(1-cyanocyclopropyl)-3-( cyclopropylmethylsulfonyl)-2-((S)-1,1 -difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-ylamino)propanamide;
E. (R)-N-(1-cyanocyclopropyl)-2-((S)-1, 1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-3-(pyridin-2-ylmethylthio)propanamide;
F. (R)-N-(1-cyanocyclopropyl)-2-((S)-1,1-difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-ylamino)-3-(pyridin-2-ylmethylsulfonyl)propanamide;
G. (R)-N-(1-cyanocyclopropyl)-3-((S)-1,1-difluoro-1-(4-(methylthio)phenoxy)pent-3-yn-2-ylamino)-2-((pyridin-3-ylmethylthio)methyl)propanamide;
H. (R)-N-(1-cyanocyclopropyl)-3-((S)-1,1 1-difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-ylamino)-2-((pyridin-3-ylmethylsulfonyl)methyl)propanamide;
I. 3-(((R)-3-(1 -cyanocyclopropylamino)-2-(((S)-1, 1-difluoro-1-(4-(methylsulfonyl)phenoxy)pent-3-yn-2-ylamino)methyl)-3-oxopropylsulfonyl)methyl)pyridine
1-oxide.
J. (S)-N-cyclopropyl-3-((R)-3-(cyclopropylmethylsulfonyl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)propanamido)-2-oxopentanamide.
K. (S)-5-cyclopropyl-N-((S)-1-(cyclopropylamino)-1,2-dioxopentan-3-yl)-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide.
L. (S)-N-(1-cyanocyclopropyl)-5-cyclopropyl-2-(2,2-difluoro-2-(4-fluorophenoxy)ethylamino)-4,4-difluoropentanamide. |
EXAMPLE 1
Representative pharmaceutical formulations containing a Compound of Formula I
ORAL FORMULATION
[0314]
| Compound of Formula I |
10-100 mg |
| Citric Acid Monohydrate |
105 mg |
| Sodium Hydroxide |
18 mg |
| Flavoring |
|
| Water |
q.s. to 100 ml |
INTRAVENOUS FORMULATION
[0315]
| Compound of Formula I |
0.1-10 mg |
| Dextrose Monohydrate |
q.s. to make isotonic |
| Citric Acid Monohydrate |
1.05 mg |
| Sodium Hydroxide |
0.18 mg |
| Water for Injection |
q.s. to 1.0 ml |
TABLET FORMULATION
[0316]
| Compound of Formula I |
1% |
| Microcrystalline Cellulose |
73% |
| Stearic Acid |
25% |
| Colloidal Silica |
1% |