FIELD OF THE INVENTION
[0001] The present invention relates to certain 4-amino-2-butenamides that are cathepsin
C inhibitors, pharmaceutical compositions containing these compounds, and said compounds
for use in the treatment of diseases mediated by the cathepsin C enzyme such as chronic
obstructive pulmonary disease.
BACKGROUND OF THE INVENTION
[0002] Cathepsins are a family of enzymes included in the papain superfamily of cysteine
proteases. Cathepsins B, C, F, H, K, L, S, V, and X have been described in the scientific
literature. Cathepsin C is also known in the literature as Dipeptidyl Peptidase I
or "DPPI."
[0003] US2010/0286118 discloses nitrile compounds which possess DPPI activity. A number of recently published
studies have begun to describe the role cathepsin C plays in certain inflammatory
processes. See e.g.
Adkison et al., The Journal of Clinical Investigation 109:363-371 (2002);
Tran et al., Archives of Biochemistry and Biophysics 403:160-170 (2002);
Thiele et al., The Journal of Immunology 158: 5200-5210 (1997);
Bidere et al., The Journal of Biological Chemistry 277: 32339-32347 (2002);
Mabee et al., The Journal of Immunology 160: 5880-5885;
McGuire et al., The Journal of Biological Chemistry, 268: 2458-2467; and
Paris et al., FEBS Letters 369: 326-330 (1995). From these studies, it appears that cathepsin C is co-expressed in granules with
certain serine proteases and functions to process the pro-forms of these proteases
to active forms, which are then released from the granules of inflammatory cells recruited
to sites of inflammation. Once activated, these proteases have a number of functions
including degradation of various extracellular matrix components, which together can
propagate tissue damage and chronic inflammation.
[0004] For example, Chronic Obstructive Pulmonary Disease ("COPD") is a chronic inflammatory
disease where cathepsin C appears to play a role. Chronic bronchitis and emphysema
usually occur together in COPD patients. Chronic bronchitis is generally characterized
by a chronic productive cough, whereas emphysema is generally characterized by permanent
enlargement of the airspaces distal to the terminal bronchioles and airway wall destruction.
[0005] Cigarette smoking is a significant risk factor for developing COPD. Exposure to cigarette
smoke and other noxious particles and gases may result in chronic inflammation of
the lung. In response to such exposure, inflammatory cells such as CD8+ T cells, macrophages,
and neutrophils are recruited to the area. These recruited inflammatory cells release
proteases, which are believed to play a major role in the disease etiology by a number
of mechanisms. Proteases believed to be involved in this process include the serine
proteases neutrophil elastase ("NE"), cathepsin G, and proteinase 3, all released
from neutrophils; granzymes A and B, released from cytotoxic T cells or natural killer
cells; and chymases, released from mast cells. Cathepsin C appears to be involved
in activating all of these enzymes. Additionally, cathepsin C knockout mice are resistant
to lung airspace enlargement and inflammatory cell infiltration in both cigarette
smoke and ozone exposure models of COPD. See
Guay et al., Current Topics in Medicinal Chemistry, 2010, 10, 708-716; See also
Podolin et al. (2008), Inflammation Research, 57(Suppl 2) S104.
[0006] Rheumatoid arthritis ("RA") is another chronic inflammatory disease where cathepsin
C may play a role. Neutrophils are recruited to the site of joint inflammation and
release cathepsin G, NE, and proteinase 3, which are believed to be responsible in
part for cartilage destruction associated with RA (
Hu, Y. and Pham, C. T. (2005) Arthritis Rheum 52: 2553-2558).
[0007] Other conditions where cathepsin C may play a role include osteoarthritis, asthma,
and Multiple Sclerosis. See e.g.
Matsui, K.; Yuyama, N.; Akaiwa, M.; Yoshida, N. L.; Maeda, M.; Sugita, Y.; Izuhara,
K., Identification of an alternative splicing variant of cathepsin C/dipeptidyl-peptidase
I, Gene. 293(1-2):1-7, 2002 Jun 26;
Wolters, P. J.; Laig-Webster, M.; Caughey, G. H., Dipeptidyl peptidase I cleaves matrix-associated
proteins and is expressed mainly by mast cells in normal dog airways, American Journal
of Respiratory Cell & Molecular Biology. 22(2):183-90, 2000.
[0008] One approach to treating these conditions is to inhibit the activity of the serine
proteases involved in the inflammatory process, especially NE activity. See e.g.,
Ohbayashi, "Neutrophil elastase inhibitors as treatment for COPD", Expert Opin. Investig.
Drugs 11(7): 965-980 (2002);
Shapiro, "Neutrophil Elastase: Path Clearer, Pathogen Killer, or Just Pathologic?",
Am. J. Respir. Cell Mol. Biol. 26: 266-268 (2002). In light of the role cathepsin C plays in activating certain serine proteases,
especially NE, it is desirable to prepare compounds that inhibit its activity, which
thereby inhibit serine protease activity. Thus, there is a need to identify compounds
that inhibit cathepsin C, which can be used in the treatment of a variety of conditions
mediated by cathepsin C.
[0009] There are additional activities of cathepsin C that may also be related to disease
etiology. Cathepsin C has been demonstrated to have a role in neutrophil migration
in the development of aortic aneurysms by a mechanism which has not been clearly elucidated
(
Pagano, M. B. et al. (2007) PNAS 104: 2855-2860). Thus, disease processes that involve neutrophil migration, as well as proteolytic
enzyme release can be modulated by cathepsin C inhibition. Also, cathepsin C is highly
expressed in the lung epithelium where it may play a role in the processing of other
enzymes not yet identified. Cathepsin C has also been reported to cleave kallikrein-4,
which is believed to play a role in dental enamel maturation (
Tye, C. E. et al. (2009) J. Dental Res. 88: 323-327). Finally, cathepsin C is itself released from cells and may play a direct role in
the degradation of matrix proteins.
SUMMARY OF THE INVENTION
[0010] The present invention involves novel compounds according to Formula (I) or a pharmaceutically
acceptable salt thereof:

wherein:
R1 and R2 are each independently selected from the group consisting of hydrogen, (C1-C8)alkyl, (C2-C8)alkenyl, (C2-C8)alkynyl, (C3-C8)cycloalkyl, (C5-C8)cycloalkenyl, (C6-C10)bicycloalkyl, heterocycloalkyl, (C3-C8)cycloalkyl(C1-C6)alkyl, (C5-C8)cycloalkenyl(C1-C6)alkyl, heterocycloalkyl(C1-C6)alkyl, aryl, heteroaryl, aryl(C1-C6)alkyl, and heteroaryl(C1-C6)alkyl;
wherein any (C1-C8)alkyl, (C2-C8)alkenyl, or (C2-C8)alkynyl is optionally substituted one to three times, independently, by -CF3, cyano, -CO2(C1-C4)alkyl, -CONH(C1-C4)alkyl, -CON(C1-C4)alkyl(C1-C4)alkyl, -SO2(C1-C4)alkyl, -SO2NH(C1-C4)alkyl, -SO2N(C1-C4)alkyl(C1-C4)alkyl, amino, (C1-C4)alkylamino, ((C1-C4)alkyl)((C1-C4)alkyl)amino, hydroxyl, or (C1-C4)alkoxy;
and wherein any cycloalkyl, cycloalkenyl, bicycloalkyl, or heterocycloalkyl group
is optionally substituted one to three times, independently, by (C1-C4)alkyl, (C1-C4)haloalkyl, cyano, -CO2(C1-C4)alkyl, -CONH(C1-C4)alkyl, -CON(C1-C4)alkyl(C1-C4)alkyl, -SO2(C1-C4)alkyl, -SO2NH(C1-C4)alkyl, -SO2N(C1-C4)alkyl(C1-C4)alkyl, amino, (C1-C4)alkylamino, ((C1-C4)alkyl)((C1-C4)alkyl)amino, hydroxyl, (C1-C4)alkoxy, aryl, or aryl(C1-C4)alkyl, wherein the aryl moiety of said aryl or aryl(C1-C4)alkyl is optionally substituted one to three times, independently, by halogen, -CF3, (C1-C4)alkyl, hydroxyl, or (C1-C4)alkoxy;
and wherein any aryl or heteroaryl group is optionally substituted one to three times,
independently, by halogen, (C1-C6)alkyl, (C3-C6)cycloalkyl, (C5-C6)cycloalkenyl, (C1-C6)haloalkyl, cyano, -CO2(C1-C4)alkyl, -CONH(C1-C4)alkyl, -CON(C1-C4)alkyl(C1-C4)alkyl, -SO2(C1-C4)alkyl, -SO2NH(C1-C4)alkyl, -SO2N(C1-C4)alkyl(C1-C4)alkyl, amino, (C1-C4)alkylamino, ((C1-C4)alkyl)((C1-C4)alkyl)amino, hydroxyl, (C1-C4)alkoxy, (C1-C4)alkylthio-, aryl, heteroaryl, aryl(C1-C4)alkyl, or heteroaryl(C1-C4)alkyl;
wherein any aryl or heteroaryl moiety of said aryl, heteroaryl, aryl(C1-C4)alkyl, or heteroaryl(C1-C4)alkyl is optionally substituted one to three times, independently, by halogen, -CF3, (C1-C4)alkyl, hydroxyl, or (C1-C4)alkoxy;
and wherein any (C3-C6)cycloalkyl is optionally substituted one to three times, independently, by (C1-C4)alkyl, aryl, or heteroaryl;
wherein said aryl or heteroaryl is optionally substituted one to three times, independently,
by halogen, -CF3, (C1-C4)alkyl, hydroxyl, or (C1-C4)alkoxy;
or R1 and R2 taken together with the nitrogen to which they are attached represent a 5- to 7-membered
saturated or unsaturated ring optionally containing one other heteroatom which isoxygen,
nitrogen, orsulfur, wherein said ring is optionally fused to a (C3-C8)cycloalkyl, heterocycloakyll, alyl, or heteroaryl ring;
or R1 and R2 taken together with the nitrogen to which they are attached represent a 6- to 10-membered
bridged bicyclic ring system optionally fused to a(C3-C8)cycloalkyl, heterocycloalkyl, aryl, or heteroaryl ring; and
R3 is hydrogen, (C1-C8)alkyl, (C1-C8)haloalkyl, (C2-C8)alkenyl, (C2-C8)alkynyl, (C3-C6)cycloalkyl,(C5-C6)cycloalkenyl,(C3-C6)cycloalkyl(C1-C4)alkyl, (C5-C6)cycloalkenyl(C1-C4)alkyl, or aryl(C1-C4)alkyl, wherein the aryl moietyof the alyl(C1-C4)alkyl is optionally substituted one to three times, independently, by halogen, (C1-C4)alkyl, or-CF3.
[0011] The present invention is also directed to a compound of Formula (I) or a pharmaceutically
acceptable salt thereof for use in the prevention, management or treatment of a respiratory
or inflammatory disease, such aschronic obstructive pulmonarydiseaseor rhinitis.
[0012] In a further aspect, this invention relates to a pharmaceutically acceptable formulation
comprising a compound of Formula (I) or a pharmaceutically acceptable salt thereof
and a pharmaceutically acceptable excipient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013]
Fig. 1 shows the accumulation of total leukocytes in the Bronchoalveolar Lavage Fluid
of C57BL/6 Mice following twice daily oral administration of the compounds of Example
1 and 2 at the indicated doses for the final 6 weeks du ring 18 weeks of cigarette
smoke exposure.
Fig. 2 shows the accumulation of neutrophils in the Bronchoalveolar Lavage Fluid of
C57BL/6 Mice following twice daily oral administration of the compounds of Example
1 and 2 at the indicated doses for the final 6 weeks during 18 weeks of cigarette
smoke exposure.
Fig. 3 shows the accumulation of mononuclear cells in the Bronchoalveolar Lavage Fluid
of C57BL/6 Mice following twice daily oral administration of the compounds of Example
1 and 2 at the indicated doses for the final 6 weeks during 18 weeks of cigarette
smoke exposure.
DETAILED DESCRIPTION OF THE INVENTION
Terms and Definitions
[0014] As used herein, the term "alkyl" refers to a straight- or branched-chain hydrocarbon
radical having the specified number of carbon atoms. As used herein, the terms "(C
1-C
4)alkyl" and "(C
1-C
8)alkyl" refer to an alkyl group having at least 1 and up to 4 or 8 carbon atoms respectively.
Examples of such branched or straight-chained alkyl groups useful in the present invention
include, but are not limited to, methyl, ethyl,
n-propyl, isopropyl,
n-butyl, isobutyl,
s-butyl,
t-butyl,
n-pentyl, isopentyl,
n-hexyl,
n-heptyl,
n-octyl, and branched analogs of the latter 3 normal alkanes.
[0015] When the term "alkyl" is used in combination with other substituent groups, such
as "(C
1-C
4)haloalkyl" or "aryl(C
1-C
4)alkyl", the term "alkyl" is intended to encompass a divalent straight or branched-chain
hydrocarbon radical, wherein the point of attachment is through the alkyl moiety.
Examples of "(C
1-C
4)haloalkyl" groups useful in the present invention include, but are not limited to,
-CF
3 (trifluoromethyl), -CCl
3 (trichloromethyl), 1,1-difluoroethyl, 2,2,2-trifluoroethyl, and hexafluoroisopropyl.
Examples of "aryl(C
1-C
4)alkyl " groups useful in the present invention include, but are not limited to, benzyl
(phenylmethyl), 1-methylbenzyl (1-phenylethyl), 1,1-dimethylbenzyl (1-phenylisopropyl),
and phenethyl (2-phenylethyl).
[0016] As used herein, the term "alkenyl" refers to straight or branched hydrocarbon chains
containing the specified number of carbon atoms and at least 1 and up to 3 carbon-carbon
double bonds. Examples include ethenyl and propenyl.
[0017] As used herein, the term "alkynyl" refers to straight or branched hydrocarbon chains
containing the specified number of carbon atoms and at least 1 and up to 3 carbon-carbon
triple bonds. Examples include ethynyl and propynyl.
[0018] As used herein, the term "cycloalkyl" refers to a non-aromatic, saturated, cyclic
hydrocarbon ring containing the specified number of carbon atoms. The term "(C
3-C
8)cycloalkyl" refers to a non-aromatic cyclic hydrocarbon ring having from three to
eight ring carbon atoms. Exemplary "(C
3-C
8)cycloalkyl" groups useful in the present invention include cyclopropyl, cyclobutyl,
cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.
[0019] As used herein, the term "cycloalkenyl" refers to a non-aromatic, cyclic hydrocarbon
ring containing the specified number of carbon atoms and at least one carbon-carbon
double bond. The term "(C
5-C
8)cycloalkenyl" refers to a non-aromatic cyclic hydrocarbon ring having from five to
eight ring carbon atoms. Exemplary "(C
5-C
8)cycloalkenyl" groups useful in the present invention include cyclopentenyl, cyclohexenyl,
cycloheptenyl, and cyclooctenyl.
[0020] As used herein, the term "bicycloalkyl" refers to a saturated, bridged, bicyclic
hydrocarbon ring system containing the specified number of carbon atoms. The term
"(C
6-C
10)bicycloalkyl" refers to a bicyclic hydrocarbon ring system having from six to ten
carbon atoms. Exemplary "(C
6-C
10)bicycloalkyl" groups useful in the present invention include bicyclo[2.1.1]hexyl,
bicyclo[2.1.1]heptyl, bicyclo[3.2.1]octyl, bicyclo[2.2.2]octyl, bicyclo[3.2.2]nonyl,
bicyclo[3.3.1]nonyl, bicyclo[3.3.2]decyl, and bicyclo[4.3.1]decyl.
[0021] "Alkoxy" means an alkyl radical containing the specified number of carbon atoms attached
through an oxygen linking atom. The term "(C
1-C
4)alkoxy" refers to a straight-or branched-chain hydrocarbon radical having at least
1 and up to 4 carbon atoms attached through an oxygen linking atom. Exemplary "(C
1-C
4)alkoxy" groups useful in the present invention include, but are not limited to, methoxy,
ethoxy, n-propoxy, isopropoxy,
n-butoxy,
s-butoxy, and
t-butoxy.
[0022] "Alkylthio-" means an alkyl radical containing the specified number of carbon atoms
attached through a sulfur linking atom. The term "(C
1-C
4)alkylthio-" refers to a straight- or branched-chain hydrocarbon radical having at
least 1 and up to 4 carbon atoms attached through a sulfur linking atom. Exemplary
"(C
1-C
4)alkylthio-" groups useful in the present invention include, but are not limited to,
methylthio-, ethylthio-,
n-propylthio-, isopropylthio-,
n-butylthio-,
s-butylthio-, and
t-butylthio-.
[0023] "Heterocycloalkyl" means a non-aromatic heterocyclic ring containing 3-8 or 5-6 ring
atoms, being saturated or having one or more degrees of unsaturation and containing
one or more heteroatom substitutions selected from O, S, and/or N. Such a ring may
be optionally fused to one or more other heterocycloalkyl ring(s) or cycloalkyl ring(s).
Examples of "heterocycloalkyl" moieties include, but are not limited to, aziridinyl,
thiiranyl, oxiranyl, azetidinyl, oxetanyl, thietanyl, tetrahydrofuranyl, dihydropyranyl,
tetrahydropyranyl, 1,4-dioxanyl, 1,3-dioxanyl, piperidinyl, piperazinyl, 2,4-piperazinedionyl,
pyrrolidinyl, pyrrolinyl, imidazolidinyl, pyrazolidinyl, pyrazolinyl, morpholinyl,
thiomorpholinyl, tetrahydrothiopyranyl, tetrahydrothienyl, and the like.
[0024] "Aryl" refers to optionally substituted monocyclic or fused bicyclic groups having
6 to 14 carbon atoms and having at least one aromatic ring that complies with Hückel's
Rule. Examples of "aryl" groups are phenyl, naphthyl, indenyl, dihydroindenyl, anthracenyl,
phenanthrenyl, and the like. "Heteroaryl" means an optionally substituted aromatic
monocyclic ring or fused bicyclic ring system wherein at least one ring complies with
Hückel's Rule, has the specified number of ring atoms, and that ring contains at least
one heteroatom selected from N, O, and/or S. Examples of 5-membered "heteroaryl" groups
include furanyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl,
thiazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, and isothiazolyl. Examples
of 6-membered "heteroaryl" groups include oxo-pyridyl, pyridinyl, pyridazinyl, pyrazinyl,
and pyrimidinyl. Examples of 6,6-fused "heteroaryl" groups include quinolinyl, isoquinolinyl,
quinoxalinyl, cinnolinyl, phthalazinyl, quinazolinyl, 1,5-naphthyridinyl, 1,6-naphthyridinyl,
1,7-naphthyridinyl, 1,8-naphthyridinyl, and pteridinyl. Examples of 6,5-fused "heteroaryl"
groups include benzofuranyl, benzothienyl, benzimidazolyl, benzthiazolyl, indolizinyl,
indolyl, isoindolyl, and indazolyl.
[0025] For the avoidance of doubt, all bicyclic ring systems may be attached at any suitable
position on either ring.
[0026] As used herein, "halogen" or "halo" refers to F, Cl, Br, or I.
[0027] "Optionally substituted" indicates that a group, such as alkyl, alkenyl, alkynyl,
cycloalkyl, cycloalkenyl, bicycloalkyl, alkoxy, heterocycloalkyl, aryl, or heteroaryl,
may be unsubstituted, or the group may be substituted with one or more substituent(s)
as defined. In the case where groups may be selected from a number of alternative
groups the selected groups may be the same or different.
[0028] The term "independently" means that where more than one substituent is selected from
a number of possible substituents, those substituents may be the same or different.
That is, each substituent is separately selected from the entire group of recited
possible substituents (e.g. a group of substituents provided herein for various aryl
or heteroaryl is halogen, -CF
3, (C
1-C
4)alkyl, hydroxyl, and (C
1-C
4)alkoxy).
[0029] The alternative definitions for the various groups and substituent groups of Formula
(I) provided throughout the specification are intended to particularly describe each
compound species disclosed herein, individually, as well as groups of one or more
compound species. The scope of this invention includes any combination of these group
and substituent group definitions. The compounds of the invention are only those which
are contemplated to be "chemically stable" as will be appreciated by those skilled
in the art.
[0030] Suitably, R
1 and R
2 are each independently selected from the group consisting of hydrogen, (C
1-C
8)alkyl, (C
2-C
8)alkenyl, (C
2-C
8)alkynyl, (C
3-C
8)cycloalkyl, (C
5-C
8)cycloalkenyl, (C
6-C
10)bicycloalkyl, heterocycloalkyl, (C
3-C
8)cycloalkyl(C
1-C
6)alkyl, (C
5-C
8)cycloalkenyl(C
1-C
6)alkyl, heterocycloalkyl(C
1-C
6)alkyl, aryl, heteroaryl, aryl(C
1-C
6)alkyl, and heteroaryl(C
1-C
6)alkyl;
wherein any (C1-C8)alkyl, (C2-C8)alkenyl, or (C2-C8)alkynyl is optionally substituted one to three times, independently, by -CF3, cyano, -CO2(C1-C4)alkyl, -CONH(C1-C4)alkyl, -CON(C1-C4)alkyl(C1-C4)alkyl, -SO2(C1-C4)alkyl, -SO2NH(C1-C4)alkyl, -SO2N(C1-C4)alkyl(C1-C4)alkyl, amino, (C1-C4)alkylamino, ((C1-C4)alkyl)((C1-C4)alkyl)amino, hydroxyl, or (C1-C4)alkoxy;
and wherein any cycloalkyl, cycloalkenyl, bicycloalkyl, or heterocycloalkyl group
is optionally substituted one to three times, independently, by (C1-C4)alkyl, (C1-C4)haloalkyl, cyano, -CO2(C1-C4)alkyl, -CONH(C1-C4)alkyl, -CON(C1-C4)alkyl(C1-C4)alkyl, -SO2(C1-C4)alkyl, -SO2NH(C1-C4)alkyl, -SO2N(C1-C4)alkyl(C1-C4)alkyl, amino, (C1-C4)alkylamino, ((C1-C4)alkyl)((C1-C4)alkyl)amino, hydroxyl, (C1-C4)alkoxy, aryl, or aryl(C1-C4)alkyl; wherein the aryl moiety of said aryl or aryl(C1-C4)alkyl is optionally substituted one to three times, independently, by halogen, -CF3, (C1-C4)alkyl, hydroxyl, or (C1-C4)alkoxy;
and wherein any aryl or heteroaryl group is optionally substituted one to three times,
independently, by halogen, (C1-C6)alkyl, (C3-C6)cycloalkyl, (C5-C6)cycloalkenyl, (C1-C6)haloalkyl, cyano, -CO2(C1-C4)alkyl, -CONH(C1-C4)alkyl, -CON(C1-C4)alkyl(C1-C4)alkyl, -SO2(C1-C4)alkyl, -SO2NH(C1-C4)alkyl, -SO2N(C1-C4)alkyl(C1-C4)alkyl, amino, (C1-C4)alkylamino, ((C1-C4)alkyl)((C1-C4)alkyl)amino, hydroxyl, (C1-C4)alkoxy, (C1-C4)alkylthio-, aryl, heteroaryl, aryl(C1-C4)alkyl, or heteroaryl(C1-C4)alkyl;
wherein any aryl or heteroaryl moiety of said aryl, heteroaryl, aryl(C1-C4)alkyl, or heteroaryl(C1-C4)alkyl is optionally substituted one to three times, independently, by halogen, -CF3, (C1-C4)alkyl, hydroxyl, or (C1-C4)alkoxy;
and wherein any (C3-C6)cycloalkyl is optionally substituted one to three times, independently, by (C1-C4)alkyl, aryl, or heteroaryl;
wherein said aryl or heteroaryl is optionally substituted one to three times, independently,
by halogen, -CF3, (C1-C4)alkyl, hydroxyl, or (C1-C4)alkoxy.
[0031] In another embodiment, R
1 and R
2 are each independently selected from the group consisting of hydrogen, (C
1-C
6)alkyl, (C
3-C
7)cycloalkyl, (C
7-C
9)bicycloalkyl, heterocycloalkyl, (C
3-C
7)cycloalkyl(C
1-C
4)alkyl, phenyl, heteroaryl, phenyl(C
1-C
4)alkyl, and heteroaryl(C
1-C
4)alkyl;
wherein any (C1-C6)alkyl group is optionally substituted one to three times, independently, by (C3-C6)cycloalkyl, -CF3, cyano, -CO2(C1-C4)alkyl, hydroxyl, or (C1-C4)alkoxy;
and wherein any cycloalkyl, bicycloalkyl, or heterocycloalkyl group is optionally
substituted one to three times, independently, by (C1-C4)alkyl, -CF3, cyano, -CO2(C1-C4)alkyl, hydroxyl, (C1-C4)alkoxy, phenyl, or phenyl(C1-C2)alkyl; wherein the phenyl moiety of said phenyl or phenyl(C1-C2)alkyl is optionally substituted one to three times, independently, by halogen, -CF3, (C1-C4)alkyl, hydroxyl, or (C1-C4)alkoxy;
and wherein any phenyl or heteroaryl group is optionally substituted one to three
times, independently, by halogen, (C1-C6)alkyl, (C3-C6)cycloalkyl, -CF3, cyano, -CO2(C1-C4)alkyl, -SO2(C1-C4)alkyl, hydroxyl, (C1-C4)alkoxy, (C1-C4)alkylthio-, phenyl, heteroaryl, phenyl(C1-C4)alkyl, or heteroaryl(C1-C4)alkyl;
wherein any phenyl or heteroaryl moiety of said phenyl, heteroaryl, phenyl(C1-C4)alkyl, or heteroaryl(C1-C4)alkyl is optionally substituted one to three times, independently, by halogen, -CF3, or (C1-C4)alkyl;
and wherein any (C3-C6)cycloalkyl is optionally substituted one to three times, independently, by (C1-C4)alkyl, phenyl, or heteroaryl;
wherein said phenyl or heteroaryl is optionally substituted one to three times, independently,
by halogen, -CF3, or (C1-C4)alkyl.
[0032] In a further embodiment, R
1 is selected from the group consisting of (C
1-C
6)alkyl, (C
3-C
7)cycloalkyl, (C
7-C
9)bicycloalkyl, heterocycloalkyl, (C
3-C
7)cycloalkyl(C
1-C
2)alkyl, phenyl, heteroaryl, and phenyl(C
1-C
2)alkyl; wherein any cycloalkyl or heterocycloalkyl group is optionally substituted
one to two times, independently, by (C
1-C
4)alkyl, -CF
3, hydroxyl, or (C
1-C
4)alkoxy, and wherein any phenyl or heteroaryl group is optionally substituted one
to two times, independently, by halogen, (C
1-C
4)alkyl, -CF
3, cyano, -CO
2(C
1-C
4)alkyl, hydroxyl, (C
1-C
4)alkoxy, or (C
1-C
4)alkylthio-. In yet a further embodiment, R
1 is phenyl optionally substituted one to two times, independently, by halogen, (C
1-C
4)alkyl, -CF
3, cyano, -CO
2(C
1-C
4)alkyl, hydroxyl, (C
1-C
4)alkoxy, or (C
1-C
4)alkylthio-. In yet a further embodiment, R
1 is furanyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, thiazolyl,
oxazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, or isothiazolyl optionally substituted
by halogen, (C
1-C
4)alkyl, -CF
3, (C
3-C
6)cycloalkyl, phenyl, halophenyl, phenyl(C
1-C
4)alkyl, halophenyl(C
1-C
4)alkyl, cyano, -CO
2(C
1-C
4)alkyl, (C
1-C
4)alkoxy, or (C
1-C
4)alkylthio-; wherein said (C
3-C
6)cycloalkyl is optionally substituted by (C
1-C
4)alkyl. In yet a further embodiment, R
1 is thiadiazolyl optionally substituted by halogen, (C
1-C
4)alkyl, -CF
3, (C
3-C
6)cycloalkyl, phenyl, halophenyl, phenyl(C
1-C
4)alkyl, cyano, -CO
2(C
1-C
4)alkyl, (C
1-C
4)alkoxy, or (C
1-C
4)alkylthio-; wherein said (C
3-C
6)cycloalkyl is optionally substituted by (C
1-C
4)alkyl. In yet a further embodiment, R
1 is thiadiazolyl optionally substituted by halogen, (C
1-C
4)alkyl, -CF
3, (C
3-C
6)cycloalkyl, phenyl, cyano, -CO
2(C
1-C
4)alkyl, or (C
1-C
4)alkoxy; wherein said (C
3-C
6)cycloalkyl is optionally substituted by (C
1-C
4)alkyl. In selected embodiments, R
1 is 5-cyclohexyl-1,3,4-thiadiazol-2-yl or 5-phenyl-1,3,4-thiadiazol-2-yl.
[0033] In another embodiment, R
2 is hydrogen or (C
1-C
4)alkyl. In selected embodiments, R
2 is hydrogen or methyl. In another selected embodiment, R
2 is hydrogen.
[0034] In another embodiment, R
1 and R
2 taken together with the nitrogen to which they are attached represent a 5- to 7-membered
saturated or unsaturated ring optionally containing one other heteroatom which is
oxygen, nitrogen, or sulfur; wherein said ring is optionally fused to a (C
3-C
8)cycloalkyl, heterocycloalkyl, aryl, or heteroaryl ring. In a further embodiment,
R
1 and R
2 taken together with the nitrogen to which they are attached represent a 5- to 6-membered
saturated or unsaturated ring optionally fused to a phenyl moiety. In a selected embodiment,
R
1 and R
2 taken together with the nitrogen to which they are attached represent 1
H-indol-1-yl or 2,3-dihydro-1
H-indol-1-yl. In another selected embodiment, R
1 and R
2 taken together with the nitrogen to which they are attached represent 2,3-dihydro-1
H-indol-1-yl.
[0035] In another embodiment, R
1 and R
2 taken together with the nitrogen to which they are attached represent a 6- to 10-membered
bridged bicyclic ring system optionally fused to a (C
3-C
8)cycloalkyl, heterocycloalkyl, aryl, or heteroaryl ring. In a further embodiment,
R
1 and R
2 taken together with the nitrogen to which they are attached represent a 7- to 9-membered
bridged bicyclic ring system optionally fused to a phenyl moiety.
[0036] Suitably, R
3 is hydrogen, (C
1-C
8)alkyl, (C
1-C
8)haloalkyl, (C
2-C
8)alkenyl, (C
2-C
8)alkynyl, (C
3-C
6)cycloalkyl, (C
5-C
6)cycloalkenyl, (C
3-C
6)cycloalkyl(C
1-C
4)alkyl, (C
5-C
6)cycloalkenyl(C
1-C
4)alkyl, or aryl(C
1-C
4)alkyl; wherein the aryl moiety of the aryl(C
1-C
4)alkyl is optionally substituted one to three times, independently, by halogen, (C
1-C
4)alkyl, or -CF
3.
[0037] In another embodiment, R
3 is hydrogen, (C
1-C
6)alkyl, (C
1-C
6)haloalkyl, (C
3-C
6)cycloalkyl, (C
3-C
6)cycloalkyl(C
1-C
4)alkyl, or phenyl(C
1-C
4)alkyl; wherein the phenyl moiety of the phenyl(C
1-C
4)alkyl is optionally substituted one to three times, independently, by halogen, (C
1-C
4)alkyl, or -CF
3. In a further embodiment, R
3 is (C
1-C
6)alkyl or (C
3-C
6)cycloalkyl(C
1-C
2)alkyl. In selected embodiments, R
3 is ethyl, isobutyl, or
sec-butyl. In further selected embodiments, R
3 is cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, or cyclohexylmethyl. In
another selected embodiment, R
3 is cyclopropylmethyl. In a further embodiment, R
3 is phenyl(C
1-C
4)alkyl; wherein the phenyl moiety is optionally substituted one to two times, independently,
by halogen, (C
1-C
4)alkyl, or -CF
3. In a selected embodiment, R
3 is phenethyl.
[0038] One particular embodiment of the invention is a compound of Formula (I) or a pharmaceutically
acceptable salt thereof wherein:
R1 and R2 are each independently selected from the group consisting of hydrogen, (C1-C6)alkyl, (C3-C7)cycloalkyl, (C7-C9)bicycloalkyl, heterocycloalkyl, (C3-C7)cycloalkyl(C1-C4)alkyl, phenyl, heteroaryl, phenyl(C1-C4)alkyl, and heteroaryl(C1-C4)alkyl;
wherein any (C1-C6)alkyl group is optionally substituted one to three times, independently, by (C3-C6)cycloalkyl, -CF3, cyano, -CO2(C1-C4)alkyl, hydroxyl, or (C1-C4)alkoxy;
and wherein any cycloalkyl, bicycloalkyl, or heterocycloalkyl group is optionally
substituted one to three times, independently, by (C1-C4)alkyl, -CF3, cyano, -CO2(C1-C4)alkyl, hydroxyl, (C1-C4)alkoxy, phenyl, or phenyl(C1-C2)alkyl; wherein the phenyl moiety of said phenyl or phenyl(C1-C2)alkyl is optionally substituted one to three times, independently, by halogen, -CF3, (C1-C4)alkyl, hydroxyl, or (C1-C4)alkoxy;
and wherein any phenyl or heteroaryl group is optionally substituted one to three
times, independently, by halogen, (C1-C6)alkyl, (C3-C6)cycloalkyl, -CF3, cyano, -CO2(C1-C4)alkyl, -SO2(C1-C4)alkyl, hydroxyl, (C1-C4)alkoxy, phenyl, heteroaryl, phenyl(C1-C2)alkyl, or heteroaryl(C1-C2)alkyl;
wherein any phenyl or heteroaryl moiety of said phenyl, heteroaryl, phenyl(C1-C2)alkyl, or heteroaryl(C1-C2)alkyl is optionally substituted one to three times, independently, by halogen, -CF3, or (C1-C4)alkyl;
and wherein any (C3-C6)cycloalkyl is optionally substituted one to three times, independently, by (C1-C4)alkyl, phenyl, or heteroaryl;
wherein said phenyl or heteroaryl is optionally substituted one to three times, independently,
by halogen, -CF3, or (C1-C4)alkyl;
or R1 and R2 taken together with the nitrogen to which they are attached represent a 5- to 6-membered
saturated or unsaturated ring optionally fused to a phenyl moiety;
or R1 and R2 taken together with the nitrogen to which they are attached represent a 7- to 9-membered
bridged bicyclic ring system optionally fused to a phenyl moiety; and
R3 is (C1-C6)alkyl or (C3-C6)cycloalkyl(C1-C2)alkyl.
[0039] Another particular embodiment of the invention is a compound of Formula (I) or a
pharmaceutically acceptable salt thereof wherein:
R1 and R2 taken together with the nitrogen to which they are attached represent a 5- to 6-membered
saturated or unsaturated ring optionally fused to a phenyl moiety; and
R3 is (C1-C6)alkyl or (C3-C6)cycloalkyl(C1-C2)alkyl.
[0040] Another particular embodiment of the invention is a compound of Formula (I) or a
pharmaceutically acceptable salt thereof wherein:
R1 and R2 taken together with the nitrogen to which they are attached represent 2,3-dihydro-1H-indol-1-yl; and
R3 is (C1-C6)alkyl or (C3-C6)cycloalkyl(C1-C2)alkyl.
[0041] Another particular embodiment of the invention is a compound of Formula (I) or a
pharmaceutically acceptable salt thereof wherein:
R1 is heteroaryl optionally substituted one to two times, independently, by halogen,
(C1-C4)alkyl, -CF3, cyano, -CO2(C1-C4)alkyl, hydroxyl, or (C1-C4)alkoxy; wherein said heteroaryl is selected from the group consisting of furanyl,
thienyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, thiazolyl, oxazolyl,
isoxazolyl, oxadiazolyl, thiadiazolyl, and isothiazolyl; and
R2 is hydrogen or methyl;
R3 is (C1-C6)alkyl or (C3-C6)cycloalkyl(C1-C2)alkyl.
[0042] Another particular embodiment of the invention is a compound of Formula (I) or a
pharmaceutically acceptable salt thereof wherein:
R1 is thiadiazolyl optionally substituted by halogen, (C1-C4)alkyl, -CF3, (C3-C6)cycloalkyl, phenyl, cyano, -CO2(C1-C4)alkyl, or (C1-C4)alkoxy; wherein said (C3-C6)cycloalkyl is optionally substituted by (C1-C4)alkyl;
R2 is hydrogen or methyl; and
R3 is (C1-C6)alkyl or (C3-C6)cycloalkyl(C1-C2)alkyl.
[0043] Specific compounds of Formula (I) are:
4-amino-N-[(1S,2E)-4-(2,3-dihydro-1H-indol-1-yl)-1-ethyl-4-oxo-2-buten-1-yl]tetrahydro-2H-pyran-4-carboxamide; and
4-amino-N-[(1S,2E)-4-(2,3-dihydro-1H-indol-1-yl)-1-(2-methylpropyl)-4-oxo-2-buten-1-yl]tetrahydro-2H-pyran-4-carboxamide;
or pharmaceutically acceptable salts thereof.
[0044] The invention also includes various isomers of the compounds of Formula (I) and mixtures
thereof. "Isomer" refers to compounds that have the same composition and molecular
weight but differ in physical and/or chemical properties. The structural difference
may be in constitution (geometric isomers) or in the ability to rotate the plane of
polarized light (stereoisomers). The compounds according to Formula (I) contain one
or more asymmetric centers, also referred to as chiral centers, and may, therefore,
exist as individual enantiomers, diastereomers, or other stereoisomeric forms, or
as mixtures thereof. All such isomeric forms are included within the present invention,
including mixtures thereof.
[0045] Chiral centers may also be present in a substituent such as an alkyl group. Where
the stereochemistry of a chiral center present in Formula (I), or in any chemical
structure illustrated herein, is not specified the structure is intended to encompass
any stereoisomer and all mixtures thereof. Thus, compounds according to Formula (I)
containing one or more chiral centers may be used as racemic mixtures, enantiomerically
enriched mixtures, or as enantiomerically pure individual stereoisomers.
[0046] Individual stereoisomers of a compound according to Formula (I) which contain one
or more asymmetric centers may be resolved by methods known to those skilled in the
art. For example, such resolution may be carried out (1) by formation of diastereoisomeric
salts, complexes or other derivatives; (2) by selective reaction with a stereoisomer-specific
reagent, for example by enzymatic oxidation or reduction; or (3) by gas-liquid or
liquid chromatography in a chiral environment, for example, on a chiral support such
as silica with a bound chiral ligand or in the presence of a chiral solvent. The skilled
artisan will appreciate that where the desired stereoisomer is converted into another
chemical entity by one of the separation procedures described above, a further step
is required to liberate the desired form. Alternatively, specific stereoisomers may
be synthesized by asymmetric synthesis using optically active reagents, substrates,
catalysts or solvents, or by converting one enantiomer to the other by asymmetric
transformation.
[0047] The invention also includes various deuterated forms of the compounds of Formula
(I). Each available hydrogen atom attached to a carbon atom may be independently replaced
with a deuterium atom. A person of ordinary skill in the art will know how to synthesize
deuterated forms of the compounds of Formula (I). For example, α-deuterated α-amino
acids are commercially available or may be prepared by conventional techniques (see
for example:
Elemes, Y. and Ragnarsson, U. J. Chem. Soc., Pekin Trans. 1, 1996, 6, 537-40). Employing such compounds according to Scheme 1 below will allow for the preparation
of compounds of Formula (I) in which the hydrogen atom at the chiral center is replaced
with a deuterium atom. Similarly, α-amino acids in which deuterium atoms have been
incorporated into the sidechains are commercially available or may be prepared by
conventional techniques. Employing such compounds according to Scheme 1 below will
allow for the preparation of compounds of Formula (I) in which deuterium atoms have
been incorporated in R
3. Additionally, replacement of the reagent lithium aluminum hydride with lithium aluminum
deuteride according to Scheme 1 below will allow for deuterium substitution at the
β-position of the butenamide of the compounds of Formula (I).
[0048] The term "solvate" refers to a complex of variable stoichiometry formed by a solute
and a solvent. Such solvents for the purpose of the invention may not interfere with
the biological activity of the solute. Examples of suitable solvents include, but
are not limited to, water, methanol, ethanol and acetic acid. Preferably, the solvent
used is a pharmaceutically acceptable solvent. Examples of suitable pharmaceutically
acceptable solvents include, without limitation, water, ethanol and acetic acid. Solvates
wherein water is the solvent molecule are typically referred to as "hydrates". Hydrates
include compositions containing stoichiometric amounts of water, as well as compositions
containing variable amounts of water. Solvates, particularly hydrates, of the compounds
of Formula (I) and salts thereof, are within the scope of the invention.
[0049] When a disclosed compound or its salt is named or depicted by structure, it is to
be understood that the compound or salt, including solvates (particularly, hydrates)
thereof, may exist in crystalline forms, non-crystalline forms or a mixture thereof.
The compound or salt, or solvates (particularly, hydrates) thereof, may also exhibit
polymorphism (i.e. the capacity to occur in different crystalline forms). These different
crystalline forms are typically known as "polymorphs." It is to be understood that
when named or depicted by structure, the disclosed compound, or solvates (particularly,
hydrates) thereof, also include all polymorphs thereof. Polymorphs have the same chemical
composition but differ in packing, geometrical arrangement, and other descriptive
properties of the crystalline solid state. Polymorphs, therefore, may have different
physical properties such as shape, density, hardness, deformability, stability, and
dissolution properties. Polymorphs typically exhibit different melting points, IR
spectra, and X-ray powder diffraction patterns, which may be used for identification.
One of ordinary skill in the art will appreciate that different polymorphs may be
produced, for example, by changing or adjusting the conditions used in crystallizing/recrystallizing
the compound.
[0050] Because of their potential use in medicine, the salts of the compounds of Formula
(I) are preferably pharmaceutically acceptable. Suitable pharmaceutically acceptable
salts can include acid or base addition salts. This invention also provides for the
conversion of one pharmaceutically acceptable salt of a compound of this invention,
e.g., a hydrochloride salt, into another pharmaceutically acceptable salt of a compound
of this invention, e.g., a sulfate salt.
[0051] As used herein, the term "pharmaceutically acceptable" means a compound which is
suitable for pharmaceutical use. Salts and solvates (e.g. hydrates and hydrates of
salts) of the compounds of the invention which are suitable for use in medicine are
those wherein the counterion or associated solvent is pharmaceutically acceptable.
However, salts and solvates having non-pharmaceutically acceptable counterions or
associated solvents are within the scope of the present invention, for example, for
use as intermediates in the preparation of other compounds of the invention and their
salts and solvates.
[0052] Compounds of Formula (I) have one or more nitrogen(s) basic enough to form pharmaceutically
acceptable acid addition salts by treatment with a suitable acid. Suitable acids include
pharmaceutically acceptable inorganic acids and pharmaceutically acceptable organic
acids. Representative pharmaceutically acceptable acid addition salts include acetate,
aspartate, benzenesulfonate, benzoate, bicarbonate, bitartrate, bromide, calcium edetate,
camsylate, carbonate, chloride, citrate, dihydrochloride, edetate, edisylate, estolate,
esylate, formate, fumarate, galacturonate, gluceptate, gluconate, glutamate, glycollylarsanilate,
hexanoate, hydrobromide, hydrochloride, hydroxynaphthoate, iodide, isethionate, lactate,
lactobionate, malate, maleate, mandelate, mesylate, methylsulfate, mucate, napsylate,
nitrate, pamoate, pantothenate, phosphate/diphosphate, polygalacturonate, propionate,
salicylate, stearate, subacetate, succinate, sulfate, tannate, tartrate, teoclate,
and tosylate salts.
[0053] Other iterations of compounds of the invention have an acidic functional group, one
acidic enough to form salts. Representative salts include pharmaceutically acceptable
metal salts such as sodium, potassium, lithium, calcium, magnesium, aluminum, and
zinc salts; carbonates and bicarbonates of a pharmaceutically acceptable metal cation
such as sodium, potassium, lithium, calcium, magnesium, aluminum, and zinc; pharmaceutically
acceptable organic primary, secondary, and tertiary amines including aliphatic amines,
aromatic amines, aliphatic diamines, and hydroxy alkylamines such as methylamine,
ethylamine, 2-hydroxyethylamine, diethylamine, triethylamine, ethylenediamine, ethanolamine,
diethanolamine, cyclohexylamine, triethanolamine, choline, arginine, lysine, and histidine.
[0054] Other non-pharmaceutically acceptable salts, e.g. trifluoroacetate, may be used,
for example in the isolation of compounds of the invention, and are included within
the scope of this invention.
[0055] The invention includes within its scope all possible stoichiometric and non-stoichiometric
forms of the salts of the compounds of Formula (I).
[0056] It will be appreciated by those skilled in the art that certain protected derivatives
of compounds of Formula (I), which may be made prior to a final deprotection stage,
may not possess pharmacological activity as such, but may, in certain instances, be
administered orally or parenterally and thereafter metabolized in the body to form
compounds of the invention which are pharmacologically active. Such derivatives may
therefore be described as "prodrugs' (not forming part of the invention).
[0057] '. Further, certain compounds of the invention may act as prodrugs of other compounds
of the invention. Examples of suitable pro-drugs for the compounds of the present
invention are described in
Drugs of Today, Volume 19, Number 9, 1983, pp 499 - 538 and in
Topics in Chemistry, Chapter 31, pp 306 - 316 and in "
Design of Prodrugs" by H. Bundgaard, Elsevier, 1985, Chapter 1 (the disclosures in
which documents are incorporated herein by reference). It will further be appreciated by those skilled in the art, that certain moieties,
known to those skilled in the art as "pro-moieties", (not forming part of the invention)
for example as described by H. Bundgaard in "Design of Prodrugs" (the disclosure in
which document is incorporated herein by reference) may be placed on appropriate functionalities
when such functionalities are present within compounds of the invention. Preferred
"pro-moieties" for compounds of the invention include: ester, carbonate ester, hemi-ester,
phosphate ester, nitro ester, sulfate ester, sulfoxide, amide, carbamate, azo-, phosphamide,
glycoside, ether, acetal, and ketal derivatives of the compounds of Formula (I).
[0058] The compounds of the invention inhibit the cathepsin C enzyme and can be useful in
the treatment of conditions wherein the underlying pathology is (at least in part)
attributable to cathepsin C involvement or in conditions wherein cathepsin C inhibition
offers some clinical benefit even though the underlying pathology is not (even in
part) attributable to cathepsin C involvement. Examples of such conditions include
COPD, rheumatoid arthritis, osteoarthritis, asthma, and multiple sclerosis. Accordingly,
in another aspect the invention is directed to compounds for use in methods of treating
such conditions.
[0059] As used herein, "treatment" in reference to a condition means: (1) the amelioration
of the condition being treated or one or more of the biological manifestations of
the condition being treated, (2) the interference with (a) one or more points in the
biological cascade that leads to or is responsible for the condition being treated
or (b) one or more of the biological manifestations of the condition being treated,
or (3) the alleviation of one or more of the symptoms or effects associated with the
condition being treated.
[0060] An "effective amount" means that amount of a drug or pharmaceutical agent that will
elicit the biological or medical response of a tissue, system, animal or human that
is being sought, for instance, by a researcher or clinician. Furthermore, the term
"therapeutically effective amount" means any amount which, as compared to a corresponding
subject who has not received such amount, results in improved treatment, healing,
prevention, or amelioration of a disease, disorder, or side effect, or a decrease
in the rate of advancement of a disease or disorder. The term also includes within
its scope amounts effective to enhance normal physiological function.
[0061] As used herein, "patient" refers to a human or animal.
[0062] The compounds of the invention may be administered by any suitable route of administration,
including both systemic administration and topical administration. Systemic administration
includes oral administration, parenteral administration, transdermal administration,
rectal administration, and administration by inhalation. Parenteral administration
refers to routes of administration other than enteral, transdermal, or by inhalation,
and is typically by injection or infusion. Parenteral administration includes intravenous,
intramuscular, and subcutaneous injection or infusion. Inhalation refers to administration
into the patient's lungs whether inhaled through the mouth or through the nasal passages.
Topical administration includes application to the skin as well as intraocular, otic,
intravaginal, and intranasal administration.
[0063] The compounds of the invention may be administered once or according to a dosing
regimen wherein a number of doses are administered at varying intervals of time for
a given period of time. For example, doses may be administered one, two, three, or
four times per day. Doses may be administered until the desired therapeutic effect
is achieved or indefinitely to maintain the desired therapeutic effect. Suitable dosing
regimens for a compound of the invention depend on the pharmacokinetic properties
of that compound, such as absorption, distribution, and half-life, which can be determined
by the skilled artisan. In addition, suitable dosing regimens, including the amount
administered and the duration such regimens are administered, for a compound of the
invention depend on the condition being treated, the severity of the condition being
treated, the age and physical condition of the patient being treated, the medical
history of the patient to be treated, the nature of concurrent therapy, the particular
route of administration chosen, the desired therapeutic effect, and like factors within
the knowledge and expertise of the skilled artisan. It will be further understood
by such skilled artisans that suitable dosing regimens may require adjustment given
an individual patient's response to the dosing regimen or over time as individual
patient needs change. Typical daily dosages range from 1 mg to 1000 mg.
[0064] The invention includes the use of compounds of the invention for the preparation
of a composition for treating or ameliorating diseases mediated by the cathepsin C
enzyme in a subject in need thereof, wherein the composition comprises a mixture of
one or more of the compounds of the invention and an optional pharmaceutically acceptable
excipient.
[0065] The invention further includes compounds of the invention as an active therapeutic
substance, in particular in the treatment of diseases mediated by the cathepsin C
enzyme. Specifically, the invention includes compounds of the invention in the treatment
of COPD, rheumatoid arthritis, osteoarthritis, asthma, and multiple sclerosis.
[0066] In another aspect, the invention includes the use of compounds of the invention in
the manufacture of a medicament for use in the treatment of the above disorders.
Compositions
[0067] The compounds of the invention will normally, but not necessarily, be formulated
into a pharmaceutical composition prior to administration to a patient. Accordingly,
in another aspect the invention is directed to pharmaceutical compositions comprising
a compound of the invention and a pharmaceutically acceptable excipient.
[0068] The pharmaceutical compositions of the invention may be prepared and packaged in
bulk form wherein an effective amount of a compound of the invention can be extracted
and then given to the patient such as with powders, syrups, and solutions for injection.
Alternatively, the pharmaceutical compositions of the invention may be prepared and
packaged in unit dosage form wherein each physically discrete unit contains an effective
amount of a compound of the invention. When prepared in unit dosage form, the pharmaceutical
compositions of the invention typically contain from 1 mg to 1000 mg.
[0069] The pharmaceutical compositions of the invention typically contain one compound of
the invention. However, in certain embodiments, the pharmaceutical compositions of
the invention contain more than one compound of the invention. For example, in certain
embodiments the pharmaceutical compositions of the invention contain two compounds
of the invention. In addition, the pharmaceutical compositions of the invention may
optionally further comprise one or more additional pharmaceutically active compounds.
Conversely, the pharmaceutical compositions of the invention typically contain more
than one pharmaceutically acceptable excipient. However, in certain embodiments, the
pharmaceutical compositions of the invention contain one pharmaceutically acceptable
excipient.
[0070] As used herein, "pharmaceutically acceptable excipient" means a material, composition
or vehicle involved in giving form or consistency to the composition and which is
safe when administered to a patient. Each excipient must be compatible with the other
ingredients of the pharmaceutical composition when commingled such that interactions
which would substantially reduce the efficacy of the compound of the invention when
administered to a patient and interactions which would result in pharmaceutical compositions
that are not pharmaceutically acceptable are avoided. In addition, each excipient
must of course be of sufficiently high purity to render it pharmaceutically-acceptable.
[0071] The compounds of the invention and the pharmaceutically acceptable excipient or excipients
will typically be formulated into a dosage form adapted for administration to the
patient by the desired route of administration. For example, dosage forms include
those adapted for (1) oral administration such as tablets, capsules, caplets, pills,
troches, powders, syrups, elixirs, suspensions, solutions, emulsions, sachets, and
cachets; (2) parenteral administration such as sterile solutions, suspensions, and
powders for reconstitution; (3) transdermal administration such as transdermal patches;
(4) rectal administration such as suppositories; (5) inhalation such as aerosols and
solutions; and (6) topical administration such as creams, ointments, lotions, solutions,
pastes, sprays, foams, and gels.
[0072] Suitable pharmaceutically acceptable excipients will vary depending upon the particular
dosage form chosen. In addition, suitable pharmaceutically acceptable excipients may
be chosen for a particular function that they may serve in the composition. For example,
certain pharmaceutically acceptable excipients may be chosen for their ability to
facilitate the production of uniform dosage forms. Certain pharmaceutically acceptable
excipients may be chosen for their ability to facilitate the production of stable
dosage forms. Certain pharmaceutically acceptable excipients may be chosen for their
ability to facilitate the carrying or transporting the compound or compounds of the
invention once administered to the patient from one organ, or portion of the body,
to another organ, or portion of the body. Certain pharmaceutically acceptable excipients
may be chosen for their ability to enhance patient compliance.
[0073] Suitable pharmaceutically acceptable excipients include the following types of excipients:
diluents, fillers, binders, disintegrants, lubricants, glidants, granulating agents,
coating agents, wetting agents, solvents, co-solvents, suspending agents, emulsifiers,
sweeteners, flavoring agents, flavor masking agents, coloring agents, anti-caking
agents, humectants, chelating agents, plasticizers, viscosity increasing agents, antioxidants,
preservatives, stabilizers, surfactants, and buffering agents. The skilled artisan
will appreciate that certain pharmaceutically acceptable excipients may serve more
than one function and may serve alternative functions depending on how much of the
excipient is present in the formulation and what other ingredients are present in
the formulation.
[0076] In one aspect, the invention is directed to a solid oral dosage form such as a tablet
or capsule comprising an effective amount of a compound of the invention and a diluent
or filler. Suitable diluents and fillers include lactose, sucrose, dextrose, mannitol,
sorbitol, starch (e.g. corn starch, potato starch, and pre-gelatinized starch), cellulose
and its derivatives (e.g. microcrystalline cellulose), calcium sulfate, and dibasic
calcium phosphate. The oral solid dosage form may further comprise a binder. Suitable
binders include starch (e.g. corn starch, potato starch, and pre-gelatinized starch),
gelatin, acacia, sodium alginate, alginic acid, tragacanth, guar gum, povidone, and
cellulose and its derivatives (e.g. microcrystalline cellulose). The oral solid dosage
form may further comprise a disintegrant. Suitable disintegrants include crospovidone,
sodium starch glycolate, croscarmelose, alginic acid, and sodium carboxymethyl cellulose.
The oral solid dosage form may further comprise a lubricant. Suitable lubricants include
stearic acid, magnesium stearate, calcium stearate, and talc.
[0077] In another aspect, the invention is directed to a dosage form adapted for administration
to a patient by inhalation. For example, the compound of the invention may be inhaled
into the lungs as a dry powder, an aerosol, a suspension, or a solution.
[0078] Dry powder compositions for delivery to the lung by inhalation typically comprise
a compound of the invention as a finely divided powder together with one or more pharmaceutically
acceptable excipients as finely divided powders. Pharmaceutically acceptable excipients
particularly suited for use in dry powders are known to those skilled in the art and
include lactose, starch, mannitol, and mono-, di-, and polysaccharides.
[0079] The dry powder may be administered to the patient
via a reservoir dry powder inhaler (RDPI) having a reservoir suitable for storing multiple
(un-metered doses) of medicament in dry powder form. RDPIs typically include a means
for metering each medicament dose from the reservoir to a delivery position. For example,
the metering means may comprise a metering cup, which is movable from a first position
where the cup may be filled with medicament from the reservoir to a second position
where the metered medicament dose is made available to the patient for inhalation.
[0080] Alternatively, the dry powder may be presented in capsules (e.g. gelatin or plastic),
cartridges, or blister packs for use in a multi-dose dry powder inhaler (MDPI). MDPIs
are inhalers wherein the medicament is comprised within a multi-dose pack containing
(or otherwise carrying) multiple defined doses (or parts thereof) of medicament. When
the dry powder is presented as a blister pack, it comprises multiple blisters for
containment of the medicament in dry powder form. The blisters are typically arranged
in regular fashion for ease of release of the medicament therefrom. For example, the
blisters may be arranged in a generally circular fashion on a disc-form blister pack,
or the blisters may be elongate in form, for example comprising a strip or a tape.
Each capsule, cartridge, or blister may, for example, contain between 20µg-10mg of
the compound of the invention.
[0081] Aerosols may be formed by suspending or dissolving a compound of the invention in
a liquified propellant. Suitable propellants include halocarbons, hydrocarbons, and
other liquified gases. Representative propellants include: trichlorofluoromethane
(propellant 11), dichlorofluoromethane (propellant 12), dichlorotetrafluoroethane
(propellant 114), tetrafluoroethane (HFA-134a), 1,1-difluoroethane (HFA-152a), difluoromethane
(HFA-32), pentafluoroethane (HFA-12), heptafluoropropane (HFA-227a), perfluoropropane,
perfluorobutane, perfluoropentane, butane, isobutane, and pentane. Aerosols comprising
a compound of the invention will typically be administered to a patient
via a metered dose inhaler (MDI). Such devices are known to those skilled in the art.
[0082] The aerosol may contain additional pharmaceutically acceptable excipients typically
used with multiple dose inhalers such as surfactants, lubricants, cosolvents and other
excipients to improve the physical stability of the formulation, to improve valve
performance, to improve solubility, or to improve taste.
[0083] Suspensions and solutions comprising a compound of the invention may also be administered
to a patient
via a nebulizer. The solvent or suspension agent utilized for nebulization may be any
pharmaceutically acceptable liquid such as water, aqueous saline, alcohols or glycols,
e.g., ethanol, isopropylalcohol, glycerol, propylene glycol, polyethylene glycol,
etc. or mixtures thereof. Saline solutions utilize salts which display little or no
pharmacological activity after administration. Both organic salts, such as alkali
metal or ammonium halogen salts, e.g., sodium chloride, potassium chloride or organic
salts, such as potassium, sodium and ammonium salts or organic acids, e.g., ascorbic
acid, citric acid, acetic acid, tartaric acid, etc. may be used for this purpose.
[0084] Other pharmaceutically acceptable excipients may be added to the suspension or solution.
The compound of the invention may be stabilized by the addition of an inorganic acid,
e.g., hydrochloric acid, nitric acid, sulfuric acid and/or phosphoric acid; an organic
acid, e.g., ascorbic acid, citric acid, acetic acid, and tartaric acid, etc., a complexing
agent such as EDTA or citric acid and salts thereof; or an antioxidant such as antioxidant
such as vitamin E or ascorbic acid. These may be used alone or together to stabilize
the compound of the invention. Preservatives may be added such as benzalkonium chloride
or benzoic acid and salts thereof. Surfactant may be added particularly to improve
the physical stability of suspensions. These include lecithin, disodium dioctylsulphosuccinate,
oleic acid and sorbitan esters.
Methods of Preparation.
[0085] The compounds of Formula (I) may be obtained by using synthetic procedures illustrated
in the Schemes below or by drawing on the knowledge of a skilled organic chemist.
The synthesis provided in these Schemes are applicable for producing compounds of
the invention having a variety of different R
1-R
3 groups employing appropriate precursors, which are suitably protected if need be,
to achieve compatibility with the reactions outlined herein. Subsequent deprotection,
where needs be, and then affords compounds of the nature generally disclosed. While
the Schemes are shown with compounds only of Formula (I), they are illustrative of
processes that may be used to make the compounds of the invention.
[0086] Compounds names were generated using the software naming program ACD/Name Pro V6.02
available from Advanced Chemistry Development, Inc., 110 Yonge Street, 14
th Floor, Toronto, Ontario, Canada, M5C 1T4 (http://www.acdlabs.com/).
[0087] As shown in Scheme 1, the compounds of Formula (I) can be prepared in a multistep
sequence starting from a Boc-protected α-amino acid, such as the commercially available
(2
S)-2-({[(1,1-dimethylethyl)oxy]carbonyl}amino)butanoic acid or
N-(
tert-butoxycarbonyl)-L-leucine. Formation of an appropriate amide derivative, such as a
Weinreb amide, using an appropriate amine or amine salt, such as
N,O-dimethylhydroxylamine hydrochloride, with an appropriate coupling reagent, such as
1,1'-carbonyldiimidazole, and an appropriate base, such as DIPEA, in an appropriate
solvent, such as CH
2Cl
2, followed by reduction with an appropriate reducing agent, such as LiAlH
4, in an appropriate solvent, such as Et
2O, provides the requisite aldehyde. Enoate formation with an appropriate olefinating
reagent, such as methyl (triphenylphosphoranylidene) acetate, in an appropriate solvent,
such as Et
2O, is followed by ester hydrolysis with an appropriate reagent, such as LiOH, in an
appropriate solvent system, such as THF, MeOH, and water. This is followed by amide
bond formation with an appropriate acyclic or cyclic amine and an appropriate coupling
reagent or reagents, such as
®T3P or the BOP reagent, and an appropriate base, such as Et
3N or DIPEA, in an appropriate solvent, such as CH
2Cl
2 or DMF. Boc deprotection with an appropriate reagent, such as TFA, is followed by
coupling of the liberated amine with 4-((
tert-butoxycarbonyl)amino)tetrahydro-2
H-pyran-4-carboxylic acid, with an appropriate coupling reagent or reagents, such as
®T3P, and an appropriate base, such as Et
3N, in an appropriate solvent, such as CH
2Cl
2. Boc deprotection with an appropriate reagent, such as HCl, results in the formation
of the desired compounds of Formula (I), which may be isolated as the corresponding
salt form or converted to the free base using conventional techniques.
Reagents and conditions: a) HCl•HN(OCH
3)CH
3, DIPEA, 1,1'-carbonyldiimidazole, CH
2Cl
2; b) LiAlH
4, Et
2O; c) Ph
3P=CHCO
2CH
3, Et
2O; d) LiOH, THF, MeOH, water; e) HNR
1R
2,
®T3P, EtOAc, Et
3N, CH
2Cl
2 or HNR
1R
2, BOP reagent, DIPEA, DMF ; f) TFA, CH
2Cl
2; g) 4-((
tert-butoxycarbonyl)amino)tetrahydro-
2H-pyran-4-carboxylic acid,
®T3P, EtOAc, Et
3N, CH
2Cl
2; h) HCl, isopropanol.
SYNTHETIC EXAMPLES
[0088] The invention will now be described by reference to the following examples which
are merely illustrative and are not to be construed as a limitation of the scope of
the present invention. All temperatures are given in degrees Celsius, all solvents
are highest available purity and all reactions run under anhydrous conditions in an
argon (Ar) or nitrogen (N
2) atmosphere where necessary.
[0089] Analtech Silica Gel GF and E. Merck Silica Gel 60 F-254 thin layer plates were used
for thin layer chromatography. Both flash and gravity chromatography were carried
out on E. Merck Kieselgel 60 (230-400 mesh) silica gel. The CombiFlash
® system used for purification in this application was purchased from Isco, Inc. CombiFlash
® purification was carried out using prepacked silica gel columns, a detector with
UV wavelength at 254 nm and a variety of solvents or solvent combinations. Preparative
HPLC was performed using a Gilson Preparative System with variable wavelength UV detection
or an Agilent Mass Directed AutoPrep (MDAP) system with both mass and variable wavelength
UV detection. A variety of reverse phase columns, e.g., Luna 5u C18(2) 100A, SunFire
C 18, XBridge C18 were used in the purification with the choice of column support
dependent upon the conditions used in the purification. The compounds are eluted using
a gradient of CH
3CN and water. Neutral conditions used an CH
3CN and water gradient with no additional modifier, acidic conditions used an acid
modifier, usually 0.1% TFA (added to both the CH
3CN and water) and basic conditions used a basic modifier, usually 0.1 % NH
4OH (added to the water). Analytical HPLC was run using an Agilent system with variable
wavelength UV detection using reverse phase chromatography with an CH
3CN and water gradient with a 0.05 or 0.1% TFA modifier (added to each solvent). LC-MS
was determined using either a PE Sciex Single Quadrupole LC/MS API-150a, or Waters
ZQ instruments. The compound is analyzed using a reverse phase column, e.g., Thermo
Aquasil/Aquasil C18, Acquity UPLC C18, Thermo Hypersil Gold eluted using an CH
3CN and water gradient with a low percentage of an acid modifier such as 0.02% TFA
or 0.1% formic acid.
[0090] Nuclear magnetic resonance spectra were recorded at 400 MHz using a Bruker AVANCE
400 or Brucker DPX400 spectrometer. CDCl
3 is deuteriochloroform, DMSO-
d6 is hexadeuteriodimethylsulfoxide, and MeOD is tetradeuteriomethanol. Chemical shifts
are reported in parts per million (δ) downfield from the internal standard tetramethylsilane
(TMS) or calibrated to the residual proton signal in the NMR solvent (e.g., CHCl
3 in CDCl
3). Abbreviations for NMR data are as follows: s = singlet, d = doublet, t = triplet,
q = quartet, m = multiplet, dd = doublet of doublets, dt = doublet of triplets, app
= apparent, br = broad. J indicates the NMR coupling constant measured in Hertz. Melting
points were determined using an Electrothermal 9100 apparatus (Electrothermal Engineering
Ltd.).
[0091] Heating of reaction mixtures with microwave irradiations was carried out on a Smith
Creator (purchased from Personal Chemistry, Foxboro, MA, now owned by Biotage), an
Emrys Optimizer (purchased from Personal Chemistry) or an Explorer (purchased from
CEM, Matthews, NC) microwave.
[0092] Cartridges or columns containing polymer based functional groups (acid, base, metal
chelators, etc) can be used as part of compound workup. The "amine" columns or cartridges
are used to neutralize or basify acidic reaction mixtures or products. These include
NH2 Aminopropyl SPE-ed SPE Cartridges available from Applied Separations and diethylamino
SPE cartridges available from United Chemical Technologies, Inc.
[0093] Abbreviations are listed in the table below. All other abbreviations are as described
in the
ACS Style Guide (American Chemical Society, Washington, DC, 1986).
Table of Abbreviations
| BOP reagent: benzotriazole-1-yl-oxy-tris-(dimethylamino)-phosphonium hexafluorophosphate |
®T3P: propane phosphonic acid anhydride |
| Et3N: triethylamine |
CH2Cl2: dichloromethane |
| DIPEA: N,N-diisopropylethylamine |
DMSO: dimethyl sulfoxide |
| TFA: trifluoroacetic acid |
THF: tetrahydrofuran |
| HCl: hydrochloric acid |
DMF: N,N-dimethylformamide |
| NaHCO3: sodium bicarbonate |
EtOAc: ethyl acetate |
| Na2SO4: sodium sulfate |
Et2O: diethyl ether |
| LiAlH4: lithium aluminum hydride |
MeOH: methanol |
| mL: milliliter(s) |
CH3CN: acetonitrile |
| min: minute(s) |
aq.: aqueous |
| h: hour(s) |
M: molar |
| g: gram(s) |
mmol: millimole(s) |
| mg: milligram(s) |
RT: room temperature |
INTERMEDIATE COMPOUNDS
Intermediate 1
1,1-dimethylethyl ((1S)-1-{[methyl(methyloxy)amino]carbonyl}propyl)carbamate
[0094]

[0095] To a solution of (2
S)-2-({[(1,1-dimethylethyl)oxy]carbonyl}amino)butanoic acid (2.50 g, 12.3 mmol) in
THF (15.0 mL) was added 1,1'-carbonyldiimidazole (2.39 g, 14.8 mmol) portionwise over
about 10 min. After stirring 30 min at RT, a solution of
N,O-dimethylhydroxylamine hydrochloride (1.32 g, 13.5 mmol) and DIPEA (2.36 mL, 13.5 mmol)
in DMF (4.0 mL) was added. The reaction mixture was stirred for 2 h at RT, followed
by concentration
in vacuo. The residue was diluted with EtOAc (50 mL) and washed with 1 M aq. HCl (2 x 20 mL),
saturated aq. NaHCO
3 (2 x 20 mL), and brine (20 mL). The organic layer was dried over Na
2SO
4, filtered, and concentrated
in vacuo to afford the title compound (2.60 g, 88%) as a clear, colorless oil. LC-MS
m/
z 247 (M+H)
+, 0.94 min (ret time).
Intermediate 2
1,1-dimethylethyl [(1S)-1-formylpropyl]carbamate
[0096]

[0097] To a solution of LiAlH
4 (0.453 g, 11.9 mmol) in Et
2O (20 mL) at 0 °C was added dropwise a solution of 1,1-dimethylethyl ((1
S)-1-{[methyl(methyloxy)amino]carbonyl}-propyl)carbamate (2.67 g, 10.8 mmol) in Et
2O (15 mL). The reaction mixture was stirred for 30 min at 0 °C and quenched with EtOAc
(6.5 mL) followed by 5% aq. potassium bisulfate (6.5 mL). The reaction mixture was
washed with 1 M aq. HCl (3 x 10 mL), saturated aq. NaHCO
3 (3 x 10 mL), and brine (10 mL). The organic layer was dried over Na
2SO
4, filtered, and concentrated
in vacuo to afford the title compound as a clear, colorless oil.
Intermediate 3
methyl (2E,4S)-4-({[(1,1-dimethylethyl)oxy]carbonyl}amino)-2-hexenoate
[0098]

[0099] To a stirred solution of methyl (triphenylphosphoranylidene) acetate (4.35 g, 13.0
mmol) in Et
2O (25 mL) at RT was added a solution of Intermediate 2 in Et
2O (15 mL). The reaction mixture was stirred at RT overnight. The solid was removed
by filtration and the solution was concentrated
in vacuo. Purification
via flash column chromatography (0-50% EtOAc/hexanes) afforded the title compound (1.44
g, 55% over two steps) as a clear, colorless oil. LC-MS
m/
z 244 (M+H)
+, 0.98 min (ret time).
Intermediate 4
(2E,4S)-4-({[(1,1-dimethylethyl)oxy]carbonyl}amino)-2-hexenoic acid
[0100]

[0101] LiOH (2.95 g, 123 mmol) was added to a solution of methyl (2
E,4
S)-4-({[(1,1-dimethylethyl)oxy]carbonyl}amino)-2-hexenoate (6 g, 24.66 mmol) in THF
(50 mL), MeOH (10.00 mL), and water (50.0 mL). The reaction was stirred overnight
at RT. After 18.5 h, the reaction mixture was concentrated under reduced pressure
to remove the THF and MeOH. Water (40 mL) was added, and aqueous mixture was adjusted
to pH = 3 with 6 M aq. HCl, as measured by pH paper. EtOAc (80 mL) was added, the
layers were separated, and the aqueous layer was extracted with EtOAc (2 x 40 mL).
The combined organic layers were dried over Na
2SO
4, concentrated under reduced pressure, and dried under high vacuum, giving 6.09 g
of the title compound. LC-MS
m/
z 230 (M+H)
+, 0.77 min (ret time).
Intermediate 5
1,1-dimethylethyl [(1S,2E)-4-(2,3-dihydro-1H-indol-1-yl)-1-ethyl-4-oxo-2-buten-1-yl] carbamate
[0102]

[0103] A solution of 50 wt%
®T3P in EtOAc (22.00 mL, 37.0 mmol) was added dropwise
via addition funnel to a solution of (2
E,4
S)-4-({[(1,1-dimethylethyl)oxy]carbonyl}-amino)-2-hexenoic acid (5.65 g, 24.64 mmol),
2,3-dihydro-1
H-indole (2.76 mL, 24.64 mmol), and Et
3N (11 mL, 79 mmol) in CH
2Cl
2 (90 mL) at 0 °C (bath temp). The ice bath was removed, and the reaction was stirred
at RT. After 30 min, the reaction was quenched by dropwise addition of saturated aq.
NaHCO
3 (50 mL). The layers were separated, and the reaction was washed with 10% citric acid
(1 x 50 mL). The organic layer was concentrated under a stream of nitrogen, and the
residue was purified by flash column chromatography, giving 7.21 g (89%) of the title
compound. LC-MS
m/
z 331 (M+H)
+, 1.05 (ret time).
Intermediate 6
[(1S,2E)-4-(2,3-dihydro-1H-indol-1-yl)-1-ethyl-4-oxo-2-buten-1-yl]amine trifluoroacetate
[0104]

[0105] TFA (25 mL, 324 mmol) was added to a solution of 1,1-dimethylethyl [(1
S,2
E)-4-(2,3-dihydro-1
H-indol-1-yl)-1-ethyl-4-oxo-2-buten-1-yl]carbamate (7.21 g, 21.82 mmol) in CH
2Cl
2 (25 mL). The reaction was stirred at RT. After 3.5 h, CH
2Cl
2 (200 mL) was added, and the reaction was concentrated under reduced pressure and
dried under high vacuum. LC-MS
m/
z 231 (M+H)
+, 0.69 (ret time).
Intermediate 7
1,1-dimethylethyl [4-({[(1S,2E)-4-(2,3-dihydro-1H-indol-1-yl)-1-ethyl-4-oxo-2-buten-1-yl]amino}carbonyl)tetrahydro-2H-pyran-4-yl]carbamate
[0106]

[0107] A solution of 50 wt%
®T3P in EtOAc (1.3 mL, 2.184 mmol) was added dropwise to a solution of [(1
S,2
E)-4-(2,3-dihydro-1
H-indol-1-yl)-1-ethyl-4-oxo-2-buten-1-yl]amine trifluoroacetate (500 mg, 1.452 mmol),
4-((
tert-butoxycarbonyl)amino)tetrahydro-2
H-pyran-4-carboxylic acid (356 mg, 1.452 mmol), and Et
3N (1 mL, 7.21 mmol) in CH
2Cl
2 (5 mL) at 0 °C (bath temp). The ice bath was removed, and the reaction was stirred
at RT. After 1 h 20 min, the reaction mixture was washed with saturated aq. NaHCO
3 (1 x 5 mL) and 10% citric acid (1 x 5 mL). The organic layer was concentrated under
a stream of nitrogen, and the residue was purified by flash column chromatography,
giving 251 mg (38%) of the title compound. LC-MS
m/
z 458 (M+H)
+, 0.96 (ret time).
Intermediate 8
N2-{[(1,1-dimethylethyl)oxy]carbonyl}-N1-methyl-N1-(methyloxy)-L-leucinamide
[0108]

[0109] To a solution of
N-(
tert-butoxycarbonyl)-L-leucine (3.00 g, 13.0 mmol) in THF (25.0 mL) was added 1,1'-carbonyldiimidazole
(2.52 g, 15.6 mmol) portionwise over about 10 min. After stirring 1 h at RT, a solution
of
N,
O-dimethylhydroxylamine hydrochloride (1.39 g, 14.3 mmol) and DIPEA (2.49 mL, 14.3
mmol) in DMF (6.0 mL) was added. The reaction mixture was stirred for 2.5 h at RT,
followed by concentration
in vacuo. The residue was diluted with EtOAc (50 mL) and washed with 1 M aq. HCl (2 x 20 mL),
saturated aq. NaHCO
3 (2 x 20 mL), and brine (20 mL). The organic layer was dried over Na
2SO
4, filtered, and concentrated
in vacuo to afford the title compound (2.34 g, 66%) as a clear, colorless oil LC-MS
m/
z 275 (M+H)
+, 1.17 min (ret time).
Intermediate 9
1,1-dimethylethyl [(1S)-1-formyl-3-methylbutyl]carbamate
[0110]

[0111] To a solution of LiAlH
4 (0.356 g, 9.38 mmol) in Et
2O (20 mL) at 0 °C was added dropwise a solution of
N2-{[(1,1-dimethylethyl)oxy]carbonyl}-
N1-methyl-
N1-(methyloxy)-L-leucinamide (2.34 g, 8.53 mmol) in Et
2O (15 mL). The reaction mixture was stirred for 30 min at 0 °C and quenched with EtOAc
(6 mL) followed by 5% aq. potassium bisulfate (6 mL). The reaction mixture was washed
with 1 M aq. HCl (2 x 10 mL), saturated aq. NaHCO
3 (2 x 10 mL), and brine (10 mL). The organic layer was dried over Na
2SO
4, filtered, and concentrated
in vacuo to afford the title compound as a clear, colorless oil.
Intermediate 10
methyl (2E,4S)-4-({[(1,1-dimethylethyl)oxy]carbonyl}amino)-6-methyl-2-heptenoate
[0112]

[0113] To a stirred solution of methyl (triphenylphosphoranylidene) acetate (3.42 g, 10.2
mmol) in Et
2O (25 mL) at RT was added a solution of Intermediate 9 in Et
2O (15 mL). The reaction mixture was stirred for 15 h at RT. The solid was removed
by filtration and the solution was concentrated
in vacuo. Purification
via flash column chromatography (0-50% EtOAc/hexanes) afforded the title compound (1.74
g, 75% over two steps) as a clear, colorless oil. LC-MS
m/
z 272 (M+H)
+, 1.22 min (ret time).
Intermediate 11
(2E,4S)-4-({[(1,1-dimethylethyl)oxy]carbonyl}amino)-6-methyl-2-heptenoic acid
[0114]

[0115] To a solution of methyl (2
E,4
S)-4-({[(1,1-dimethylethyl)oxy]carbonyl}amino)-6-methyl-2-heptenoate (5.00 g, 18.43
mmol) in THF (15 mL), MeOH (15.0 mL), and water (15 mL) was added LiOH (2.206 g, 92.00
mmol). After stirring for 2 h at RT, the reaction mixture was concentrated
in vacuo. The reaction mixture was acidified with 6 M aq. HCl to pH = 5 and then extracted
with EtOAc. The organic layer was washed with water, dried over Na
2SO
4, filtered, and concentrated
in vacuo to afford the title compound (4.7 g, 99%) as a white semi-solid. LC-MS
m/
z 158 (M+H-Boc)
+, 0.94 min (ret time).
Intermediate 12
1,1-dimethylethyl [(1S,2E)-4-(2,3-dihydro-1H-indol-1-yl)-1-(2-methylpropyl)-4-oxo-2-buten-1-yl]carbamate
[0116]

[0117] To a solution of (2
E,4
S)-4-({[(1,1-dimethylethyl)oxy]carbonyl}amino)-6-methyl-2-heptenoic acid (4.70 g, 18.26
mmol) in DMF (30.0 mL) were added BOP reagent (8.08 g, 18.26 mmol) and DIPEA (6.38
mL, 36.5 mmol). After stirring at RT for 5 min, 2,3-dihydro-1
H-indole (2.053 mL, 18.26 mmol) was added and stirring continued overnight. The reaction
mixture was diluted with water and extracted with EtOAc. The organic layer was washed
with brine, dried over Na
2SO
4, filtered, concentrated
in vacuo and purified by flash column chromatography (0-20% EtOAc/hexanes) to afford the title
compound (4.83 g, 74%) as a white solid. LC-MS
m/
z 359 (M+H)
+, 1.18 min (ret time).
Intermediate 13
[(1S,2E)-4-(2,3-dihydro-1H-indol-1-yl)-1-(2-methylpropyl)-4-oxo-2-buten-1-yl]amine trifluoroacetate
[0118]

[0119] To a solution of 1,1-dimethylethyl [(1
S,2
E)-4-(2,3-dihydro-1
H-indol-1-yl)-1-(2-methylpropyl)-4-oxo-2-buten-1-yl]carbamate (3.21 g, 8.95 mmol) in
CH
2Cl
2 (10.0 mL) was added TFA (10 mL, 130 mmol). The reaction mixture was stirred for 17.5
h at RT and then concentrated under reduced pressure and dried under high vacuum to
afford the title compound. LC-MS
m/
z 259 (M+H)
+, 0.76 min (ret time).
Intermediate 14
1,1-dimethylethyl [4-({[(1S,2E)-4-(2,3-dihydro-1H-indol-1-yl)-1-(2-methylpropyl)-4-oxo-2-buten-1-yl]amino}carbonyl)tetrahydro-2H-pyran-4-yl]carbamate
[0120]

[0121] A solution of 50 wt%
®T3P in EtOAc (1.2 mL, 2.016 mmol) was added dropwise to a solution of [(1
S,2
E)-4-(2,3-dihydro-1
H-indol-1-yl)-1-(2-methylpropyl)-4-oxo-2-buten-1-yl]amine trifluoroacetate (500 mg,
1.343 mmol), 4-((
tert-butoxycarbonyl)amino)tetrahydro-2
H-pyran-4-carboxylic acid (329 mg, 1.343 mmol), and Et
3N (0.93 mL, 6.71 mmol) in CH
2Cl
2 (5 mL) at 0 °C (bath temp). The ice bath was removed, and the reaction was stirred
at RT. After 1 h 20 min, the reaction was washed with saturated aq. NaHCO
3 (1 x 5 mL) and 10% citric acid (1 x 5 mL). The organic layer was concentrated under
a stream of nitrogen, and the residue was purified by flash column chromatography,
giving 204 mg (31%) of the title compound. LC-MS
m/
z 486 (M+H)
+, 1.07 min (ret time).
COMPOUNDS OF FORMULA (I)
Example 1
4-amino-N-[(1S,2E)-4-(2,3-dihydro-1H-indol-1-yl)-1-ethyl-4-oxo-2-buten-1-yl]tetrahydro-2H-pyran-4-carboxamide hydrochloride
[0122]

[0123] A solution of concentrated aq. HCl (0.23 mL, 2.76 mmol) was added to a solution of
1,1-dimethylethyl [4-({[(1
S,2
E)-4-(2,3-dihydro-1
H-indol-1-yl)-1-ethyl-4-oxo-2-buten-1-yl]amino}carbonyl)tetrahydro-2
H-pyran-4-yl]carbamate (251 mg, 0.549 mmol) in isopropanol (2.5 mL). The reaction flask
was fitted with an air condenser, and the reaction mixture was heated to 65 °C (bath
temp) for 1 h 45 min. The solvent was evaporated under reduced pressure. Water (5
mL) was added to the residue, and the mixture was concentrated under reduced pressure
at 65 °C. Water (2 mL) was added to the residue, and the mixture was lyophilized,
giving 193.3 mg (89%) of the title compound. LC-MS
m/
z 358 (M+H)
+, 0.68 (ret time).
1H NMR (400 MHz, METHANOL-d
4) δ ppm 8.14 (br. s., 1 H); 7.25 (d,
J=7.03 Hz, 1 H); 7.18 (t,
J=7.53 Hz, 1 H); 7.02 - 7.09 (m, 1 H); 6.83 (dd,
J=15.18, 6.65 Hz, 1 H); 6.49 (d, J=14.8 Hz, 1 H); 4.56 (d,
J=7.28 Hz, 1 H); 4.22 (br. s., 2 H); 3.95 (d,
J=7.53 Hz, 1 H); 3.88 - 3.94 (m, 1 H); 3.71 - 3.78 (m, 2 H); 3.23 (br. s., 2 H); 2.39
- 2.46 (m, 2 H); 1.79 - 1.86 (m, 2 H); 1.75 (s, 1 H); 1.72 (d,
J=8.28 Hz, 1 H); 1.00 (t,
J=7.40 Hz, 3 H).
Example 2
4-amino-N-[(1S,2E)-4-(2,3-dihydro-1H-indol-1-yl)-1-(2-methylpropyl)-4-oxo-2-buten-1-yl]tetrahydro-2H-pyran-4-carboxamide
hydrochloride
[0124]

[0125] A solution of concentrated aq. HCl (0.22 mL, 2.64 mmol) was added to a solution of
1,1-dimethylethyl [4-({[(1
S,2
E)-4-(2,3-dihydro-1
H-indol-1-yl)-1-(2-methylpropyl)-4-oxo-2-buten-1-yl]amino}carbonyl)tetrahydro-2
H-pyran-4-yl]carbamate (251 mg, 0.517 mmol) in isopropanol (2.5 mL). The reaction flask
was fitted with an air condenser, and the reaction mixture was heated to 65 °C (bath
temp). After 1 h 45 min, the solvent was evaporated under reduced pressure at 60 °C.
Water (5 mL) was added to the residue, and the mixture was concentrated under reduced
pressure at 65 °C. Water (2 mL) was added to the residue, and the mixture was lyophilized,
giving 130.6 mg (60%) of the title compound. LC-MS
m/
z 386 (M+H)
+, 0.79 (ret time).
1H NMR (400 MHz, METHANOL-
d4) δ ppm 8.15 (d,
J=7.03 Hz, 1 H); 7.25 (d,
J=7.03 Hz, 1 H); 7.18 (t,
J=7.65 Hz, 1 H); 7.06 (t,
J=7.91 Hz, 1 H); 6.81 (dd,
J=15.18, 6.40 Hz, 1 H); 6.49 (br. s., 1 H); 4.73 - 4.85 (m, 2 H); 4.21 (t,
J=8.28 Hz, 2 H); 3.91 - 3.97 (m, 2 H); 3.70 - 3.77 (m, 2 H); 3.25 - 3.21 (m, 2 H);
2.35 - 2.48 (m, 2 H); 1.82 (d,
J=14.31 Hz, 2 H); 1.63 - 1.71 (m, 2 H); 1.50 - 1.57 (m, 1 H); 0.98 (dd,
J=11.92, 6.40 Hz, 6 H).
Biological Background:
Biological Assay(s)
[0126] The compounds according to Formula (I) are cathepsin C inhibitors, which indirectly
inhibit the activity of serine proteases that are activated by cathepsin C, such as
NE. The compounds according to Formula (I), therefore, are useful in the treatment
of COPD and other conditions involving cathepsin C and/or such serine proteases. The
biological activity of the compounds according to Formula (I) can be determined using
any suitable assay for determining the activity of a candidate compound as a cathepsin
C inhibitor or for determining the ability of a candidate compound to prevent the
cathepsin C mediated activation of certain serine proteases, as well as suitable tissue
and in vivo models.
A. Transpeptidation of Leucine-Leucine-O-Methyl (LLOM) cell-based Luminescence Viability
Assay
Principle:
[0127] Cathepsin C has been shown to catalyze the transpeptidation of dipeptidyl methyl-O
-esters within the lysosomes of cells from the monocytic lineage such as HL60, U937
or THP1 causing a membranolytic effect that results in cell death (
DL. Thiele, P. Lipsky PNAS 1990 Vol. 87, pp. 83-87). This mechanism was used to assess Cathepsin C in cells activity in the presence
of the compounds of the invention.
[0128] Frozen HL-60 cells were resuspended at 1.25 x 10
5 cells/mL in fresh prewarmed Iscove's modified Dulbeccos' medium (IMDM, contains 25
mM glutamine) with 20 % FBS. This suspension was dispensed (8 µL) into white low volume
384 well plates. Plates were previously stamped with 100 nL of compound at a top concentration
of 2.5 mM and serially diluted 1:3. Control and blank wells contained 100 nL of DMSO.
Each well then received 2 µL of a fresh 1.25 mM solution of leucine-leucine-OMethyl
(LLOM, Bachem) in IMDM plus 25 mM HEPES (final concentration LLOM 250 µM). The plates
were covered and incubated for 4 h at 37 °C in a 5% CO
2 incubator, then removed and equilibrated to room temperature for 10 min. Cell viability
was determined with a CellTiter-Glo luminescent assay (Promega) according to the manufacturer's
instructions. Cell viability was compared to controls containing no LLOM (100 %).
B. Recombinant Cathepsin C in vitro assay:
[0129] The activity of recombinant human cathepsin C was measured by the cleavage of a fluorogenic
substrate, H-Ser-Tyr-AMC. Briefly, 24 pM cathepsin C was incubated with test compound
(e.g. inhibitor) in a buffer consisting of 50 mM sodium acetate, 30 mM sodium chloride,
1 mM CHAPS, 1 mM dithiothreitol, 1 mM EDTA, pH 5.5 at room temperature for one hour.
After one hour of incubating test compound with cathepsin C, the activity assay was
initiated by the addition of an equal volume of 0.010 mM H-Ser-Tyr-AMC in the same
buffer. After one hour, the activity assay was stopped by the addition of 1/5 volume
of 100 µM E-64. The reaction product was measured on a fluorescence reader set at
an excitation wavelength of 360 nm and emission wavelength of 460 nm and equipped
with a 400 nm dichroic mirror.
[0130] The compounds of Examples 1 and 2 each exhibited 50% cathepsin C inhibition at a
concentration of less than 1 nM in an average of two experiments.
C. Mouse cigarette smoke exposure in vivo assay:
Mouse cigarette smoke exposure and drug administration:
[0131] Beginning at 3-4 months of age, female C57BL/6 mice (Jackson Laboratory, Bar Harbor,
ME) received nose-only exposure to 4% cigarette smoke from 3R4F cigarettes (College
of Agriculture, Reference Cigarette Program, University of Kentucky), for 2 h/day,
5 days/week for 18 weeks. Smoke was generated by a Baumgartner-Jaeger CSM 2070i Smoking
Machine (CH Technologies Inc., Westwood, NJ). During exposure to smoke or air (sham
controls), mice were maintained in restraining tubes containing stainless steel nose
cone inserts. Two hours following the final smoke exposure, bronchoalveolar lavage
(BAL) fluid (n = 3 per treatment group) was collected. During the final 6 weeks of
the 18 week exposure, mice were administered drug or vehicle alone (1% methylcellulose/25
mM citrate, pH 4.0) orally, twice daily (at 11 and 13 hour intervals), 7 days/week.
Sham-exposed mice received vehicle alone, while smoke-exposed mice received one of
the following treatments: vehicle alone, the Compound of Example 1 at 1, 10 or 30
mg/kg, or the Compound of Example 2 at 1, 10 or 30 mg/kg.
Mice received the first daily dose of drug or vehicle alone up to 1 hour prior to
the intiation of smoke/sham exposure.
Bronchoalveolar lavage:
[0132] Animals were euthanized using i.p. injection of 0.1ml Fatal Plus (Vortech Pharmaceuticals,
Dearborn, MI) and the trachea cannulated with a 3-in. section of PE90 tubing (BD,
Franklin Lakes, NJ), to which was attached a blunted 21-gauge needle connected to
a 3- way stopcock (Baxter Healthcare, Deerfield, IL). Four 1 mL aliquots of ice cold
PBS were injected and removed sequentially through the tubing separately, and the
BAL fluid centrifuged at 140×
g for 2 min. Cell pellets isolated from the four aliquots were combined and total cells
counted using a hemocytometer. Differential cell analysis was performed on cytospins
using Wright-Geimsa stain.
Statistical analysis:
[0133] Data are presented in Figures 1, 2, and 3 as the mean + S.E.M. Statistical significance
was determined using a one-way ANOVA with a Bonferroni post-test. Values of
p < 0.05 were considered significant.
*,
p < 0.05; **,
p < 0.01; ***,
p < 0.001. Percent values shown indicate percent inhibition of the window between vehicle-treated/smoke-exposed
animals and vehicle-treated/sham-exposed animals.
[0134] The compounds of the invention are believed to be useful in therapy as defined above
and to not have unacceptable or untoward effects when used in compliance with a permitted
therapeutic regime.
[0135] The foregoing examples and assay have been set forth to illustrate the invention,
not limit it. What is reserved to the inventors is to be determined by reference to
the claims.