RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/337,933, filed on May 18, 2016. The entire teachings of the above application are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates generally to compounds and pharmaceutical compositions useful as FXR modulators. Specifically, the present invention relates to isoxazole derivatives useful as agonists for FXR, and methods for their preparation and use. 
       BACKGROUND OF THE INVENTION 
       [0003]    Farnesoid X Receptor (FXR, NR1H4) is a member of the nuclear receptor family of ligand-activated transcription factors that includes receptors for the steroid, retinoid, and thyroid hormones (D. J. Mangelsdorf, et al.,  Cell,  1995, 83(6), 841-850). FXR was originally identified from a rat liver cDNA library. Farnesol and derivatives, collectively termed farnesoids, activate the rat ortholog at high concentration, but they do not modulate the human or mouse receptors. FXR is primarily expressed in the liver, kidney, and intestine (W. Seol, et al.,  Mol. Endocrinol.,  1995, 9(1), 72-85; B. M. Forman, et al.,  Cell,  1995, 81(5), 687-693). The relevant physiological ligands of FXR include the primary bile acids cholic acid (CA) and chenodeoxycholic acid (CDCA) and the secondary bile acids deoxycholic acid (DCA) and lithocholic acid (LCA) (D. Parks, et al.,  Science,  1999, 284(5418), 1362-1365). The most potent physiological ligand for FXR is CDCA, which plays a key role in regulating the expression of several genes that participate in bile acid homeostasis. FXR functions as a heterodimer with the retinoid X receptor (RXR) and binds to response elements in the promoter region of target genes to regulate gene transcription. FXR seems to be also involved in paracrine and endocrine signaling by upregulating the expression of the cytokine Fibroblast Growth Factor (J. Holt, et al.,  Genes Dev.,  2003, 17(13), 1581-1591; T. Inagaki, et al.,  Cell Metab.,  2005, 2(4), 217-225). 
         [0004]    Small molecule compounds which act as FXR modulators have been disclosed in the following publications: WO 2000/037077, WO 2002/072598, WO 2003/015771, WO 2003/099821, WO 2004/00752, WO 2004/048349, WO 2005/009387, WO 2005/082925, US 2005/0054634, WO 2007/052843, WO 2007/070796, WO 2007/076260, WO 2007/092751, WO 2007/095174, WO 2007/140174, WO 2007/140183, US 2007/0142340, WO 2008/000643, WO 2008/002573, WO 2008/025539, WO 2008/025540, WO 2008/051942, WO 2008/073825, WO 2008/157270, US 2008/0299118, US 2008/0300235, WO 2009/005998, WO 2009/012125, WO 2009/027264, WO 2009/062874, WO 2009/127321, WO 2009/149795, US 2009/0131409, US 2009/0137554, US 2009/0163474, US 2009/0163552, US 2009/0215748, WO 2010/043513, WO 2011/020615, WO 2011/117163, WO 2012/087519, WO 2012/087520, WO 2012/087521, WO 2013/007387, WO 2013/037482, WO 2013/166176, WO 2013/192097, WO 2014/184271, US 2014/0186438, US 2014/0187633, and WO 2015/017813. Further small molecule FXR modulators have been recently reviewed (R. C. Buijsman, et al.,  Curr. Med. Chem.  2005, 12(9), 1017-1075; Crawley, M. L.  Expert Opin. Ther. Patents  2010, 20(8), 1047-1057; V. Sepe, et al.,  Expert Opin. Ther. Patents  2015, 25(8), 885-896 Y. Xu,  J. Med. Chem.  2016, DOI: 10.1021/acs.jmedchem.5b00342. 
         [0005]    There is a need for the development of FXR modulators for the treatment and prevention of disease. 
       SUMMARY OF THE INVENTION 
       [0006]    In one aspect, the invention provides compounds represented by Formula (I), and pharmaceutically acceptable salts thereof: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein: 
         [0007]    R 1  is hydrogen, halogen, cyano, optionally substituted —C 1 -C 6  alkyl, optionally substituted —C 2 -C 6  alkenyl, optionally substituted —C 2 -C 6  alkynyl, optionally substituted —C 3 -C 6  cycloalkyl or optionally substituted 3- to 6-membered heterocycloalkyl; preferably, R 1  is isopropyl, tert-butyl, or cyclopropyl; 
         [0008]    R 2  is an optionally substituted aryl, optionally substituted heteroaryl, optionally substituted arylalkyl or optionally substituted heteroarylalkyl; 
         [0009]    Y is an optionally substituted aryl or optionally substituted heteroaryl; 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    is optionally substituted phenyl, optionally substituted heterocyclic or optionally substituted heteroaryl; preferably the phenyl, heterocyclic or heteroaryl is optionally substituted with one or two substituents which are independently selected from halogen, OH, cyano, SCF 3 , NH 2 , NHCH 3 , N(CH 3 ) 2 , substituted or unsubstituted —C 1 -C 8  alkyl, substituted or unsubstituted —C 1 -C 8  haloalkyl, substituted or unsubstituted —C 3 -C 6  cycloalkyl, and substituted or unsubstituted —C 1 -C 8  alkoxy; 
         [0010]    R 3  is selected from the group consisting of 
         [0000]    
       
                 
         
             
             
         
       
     
         [0011]    R 6  and R 7  are each independently selected from the group consisting of: hydrogen; optionally substituted —C 1 -C 8  alkyl; optionally substituted —C 2 -C 8  alkenyl; optionally substituted —C 2 -C 8  alkynyl; and optionally substituted —C 3 -C 8  cycloalkyl; 
         [0012]    R 8  is selected from the group consisting of: 
         [0013]    1) Optionally substituted —C 1 -C 8  alkyl; 
         [0014]    2) Optionally substituted —C 2 -C 8  alkenyl; 
         [0015]    3) Optionally substituted —C 2 -C 8  alkynyl; 
         [0016]    4) Optionally substituted —C 3 -C 8  cycloalkyl; 
         [0017]    5) Optionally substituted —C 3 -C 8  cycloalkenyl; 
         [0018]    6) Optionally substituted aryl; 
         [0019]    7) Optionally substituted arylalkyl; 
         [0020]    8) Optionally substituted heteroarylalkyl; 
         [0021]    9) Optionally substituted 3- to 8-membered heterocycloalkyl; 
         [0022]    10) Optionally substituted heteroaryl; and 
         [0023]    11) NR 10 R 11 ; 
         [0024]    R 9  is selected from the group consisting of: 
         [0025]    1) Optionally substituted aryl; 
         [0026]    2) Optionally substituted arylalkyl; 
         [0027]    3) Optionally substituted heteroarylalkyl; 
         [0028]    4) Optionally substituted 3- to 8-membered heterocycloalkyl; 
         [0029]    5) Optionally substituted heteroaryl; and 
         [0030]    6) NR 10 R 11 ;
       R 10  and R 11  are each independently selected from hydrogen, optionally substituted —C 1 -C 8  alkyl, optionally substituted —C 2 -C 8  alkenyl, optionally substituted —C 2 -C 8  alkynyl, optionally substituted —C 3 -C 8  cycloalkyl, optionally substituted aryl, optionally substituted arylalkyl, optionally substituted heteroarylalkyl, optionally substituted 3- to 8-membered heterocycloalkyl, optionally substituted heteroaryl; alternatively, R 10  and R 11  are taken together with the nitrogen atom to which they are attached to form an optionally substituted heterocyclic ring.       
 
         [0032]    In another embodiment, the present invention provides a pharmaceutical composition comprising a therapeutically effective amount of a compound formula (I), or combination of compounds of the present invention, or a pharmaceutically acceptable salt thereof, in combination with a pharmaceutically acceptable carrier or excipient. 
         [0033]    In another embodiment, the present invention provides a method for the prevention or treatment of an FXR mediated disease or condition. The method comprises administering a therapeutically effective amount of a compound of formula (I). The present invention also provides the use of a compound of Formula (I), or a pharmaceutically acceptable salt thereof, for the preparation of a medicament for the prevention or treatment of an FXR mediated disease or condition. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    In one embodiment of the present invention is a compound of Formula (I) described above, or a pharmaceutically acceptable salt thereof. 
         [0035]    In certain embodiments, the present invention relates to compounds of Formula (I), and pharmaceutically acceptable salts thereof, wherein R 1  is selected from isopropyl, tert-butyl and cyclopropyl. 
         [0036]    In certain embodiments, the present invention relates to compounds of Formula (I), and pharmaceutically acceptable salts thereof, wherein R 2  is selected from the group set forth below: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0037]    In certain embodiments, the present invention relates to compounds of Formula (I), and their pharmaceutically acceptable salts thereof, wherein Y is selected from the groups below: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein each R 5  is independently selected from the group consisting of hydroxy, —OMe, —OCH 2 F, —OCF 3 , —C 2 -C 6 -alkoxy, —C 1 -C 6 -alkyl, —C 1 -C 6  haloalkyl, halo, —C 2 -C 6  alkenyl, —C 2 -C 6  alkynyl, —C 3 -C 6  cycloalkyl, —O—C 1 -C 2  alkylphenyl, cyano, —CH 2 F, —CHF 2 , —CF 3 , —SCF 3 , —NH 2 , —NHMe, and —NMe 2 ; and b is 0, 1 or 2. In certain embodiments, R 5  is selected from halogen, —C 1 -C 6  alkyl, and —C 3 -C 6  cycloalkyl. In certain embodiments, b is 0 or 1. In certain embodiments, b is 0. 
         [0038]    In certain embodiments, the present invention relates to compounds of Formula (I), and pharmaceutically acceptable salts thereof, wherein A is phenyl, which is optionally substituted with one or two substituents independently selected from the group consisting of halogen, OH, OCH 3 , OCH 2 F, OCF 3 , CH 3 , CH 2 F, CHF 2 , CF 3 , C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl, cyano, SCF 3 , NH 2 , NHCH 3 , and N(CH 3 ) 2 . 
         [0039]    In certain embodiments, the present invention relates to compounds of Formula (I), and pharmaceutically acceptable salts thereof, wherein R 6  and R 7  are both hydrogen. 
         [0040]    In certain embodiments, the present invention relates to compounds of Formula (I), and their pharmaceutically acceptable salts thereof, wherein R 3  is selected from the group set forth below: 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0041]    In certain embodiments, the present invention relates to compounds of Formula (I), and their pharmaceutically acceptable salts thereof, wherein R 3  is selected from the group set forth below: 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0042]    In another embodiment, the present invention relates to compounds of Formula (I) represented by Formula (Ia), (Ib), (Ic), or a pharmaceutically acceptable salt, thereof: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein Y, R 1 , R 2 , R 8 , R 9 , and A are as previously defined. 
         [0043]    In another embodiment, the present invention relates to compounds of Formula (I) represented by Formula (II) or a pharmaceutically acceptable salt, thereof: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein R 3  is as previously defined. 
         [0044]    In another embodiment, the present invention relates to compounds of Formula (I) represented by Formula (III) or a pharmaceutically acceptable salt thereof: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein R 3  is as previously defined. 
         [0045]    In one embodiment, the compound of Formula (I) is represented by Formula (II) or Formula (III), or a pharmaceutically acceptable salt thereof, wherein R 3  at each occurrence is independently selected from the group set forth below: 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0046]    In another embodiment, the compound of Formula (I) is represented by Formula (II) or Formula (III), or a pharmaceutically acceptable salt thereof, wherein R 3  at each occurrence is independently selected from the group set forth below: 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0047]    In certain embodiments, the present invention provides a method for the prevention or treatment of an FXR mediated disease or condition in a subject. The method comprises administering a therapeutically effective amount of a compound of formula (I) to the subject. The present invention also provides the use of a compound of formula (I) for the preparation of a medicament for the prevention or treatment of an FXR mediated disease or condition. 
         [0048]    In certain embodiments, the FXR-mediated disease or condition is cardiovascular disease, atherosclerosis, arteriosclerosis, hypercholesteremia, or hyperlipidemia chronic liver disease, gastrointestinal disease, renal disease, metabolic disease, cancer (i.e., colorectal cancer), or neurological indications such as stroke. 
         [0049]    In certain embodiments, the chronic liver disease is primary biliary cirrhosis (PBC), cerebrotendinous xanthomatosis (CTX), primary sclerosing cholangitis (PSC), drug induced cholestasis, intrahepatic cholestasis of pregnancy, parenteral nutrition associated cholestasis (PNAC), bacterial overgrowth or sepsis associated cholestasis, autoimmune hepatitis, chronic viral hepatitis, alcoholic liver disease, nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH), liver transplant associated graft versus host disease, living donor transplant liver regeneration, congenital hepatic fibrosis, choledocholithiasis, granulomatous liver disease, intra- or extrahepatic malignancy, Sjogren&#39;s syndrome, Sarcoidosis, Wilson&#39;s disease, Gaucher&#39;s disease, hemochromatosis, or alpha 1-antitrypsin deficiency. In certain embodiments, the gastrointestinal disease is inflammatory bowel disease (IBD) (including Crohn&#39;s disease and ulcerative colitis), irritable bowel syndrome (IBS), bacterial overgrowth, malabsorption, post-radiation colitis, or microscopic colitis. 
         [0050]    In certain embodiments, the renal disease is diabetic nephropathy, focal segmental glomerulosclerosis (FSGS), hypertensive nephrosclerosis, chronic glomerulonephritis, chronic transplant glomerulopathy, chronic interstitial nephritis, or polycystic kidney disease. 
         [0051]    In certain embodiments, the cardiovascular disease is atherosclerosis, arteriosclerosis, dyslipidemia, hypercholesterolemia, or hypertriglyceridemia. 
         [0052]    In certain embodiments, the metabolic disease is insulin resistance, type I and type II diabetes, or obesity. 
         [0053]    In certain embodiments, the cancer is selected from colorectal cancer, liver cancer, heptacellular carcinoma, cholangio carcinoma, renal cancer, gastric cancer, pancreatic cancer, prostate cancer, and insulanoma. 
         [0054]    In another aspect, the invention provides a method of treating a disease selected from an inflammatory disease, an autoimmune disease and a gastrointestinal disease in a subject in need thereof. The method comprises the step of administering to the subject a therapeutically effective amount of a compound of Formula I. In another aspect, the invention provides for the use of a compound of Formula I in the manufacture of a medicament for treating an inflammatory disease, an autoimmune disease or a gastrointestinal disease. 
         [0055]    In certain embodiments, the inflammatory disease is selected from allergy, osteoarthritis, appendicitis, bronchial asthma, pancreatitis, allergic rash, and psoriasis. 
         [0056]    In certain embodiments, the autoimmune disease is selected from rheumatoid arthritis, multiple sclerosis, and type I diabetes. 
         [0057]    In certain embodiments, the gastrointestinal disease is selected from inflammatory bowel disease (Crohn&#39;s disease, ulcerative colitis), short bowel syndrome (post-radiation colitis), microscopic colitis, irritable bowel syndrome (malabsorption), and bacterial overgrowth. 
         [0058]    Yet a further aspect of the present invention is a process of making any of the compounds delineated herein employing any of the synthetic means delineated herein. 
       Definitions 
       [0059]    Listed below are definitions of various terms used to describe this invention. These definitions apply to the terms as they are used throughout this specification and claims, unless otherwise limited in specific instances, either individually or as part of a larger group. 
         [0060]    The term “alkyl”, as used herein, refers to a saturated, monovalent straight- or branched-chain hydrocarbon group. Preferred alkyl groups include C 1 -C 6  alkyl and C 1 -C 8  alkyl groups. Examples of C 1 -C 6  alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, neopentyl, n-hexyl groups; and examples of C 1 -C 8  alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, neopentyl, n-hexyl, heptyl, and octyl groups. 
         [0061]    The term “alkenyl”, as used herein, denote a monovalent group derived from a hydrocarbon moiety by the removal of a single hydrogen atom wherein the hydrocarbon moiety has at least one carbon-carbon double bond. Preferred alkenyl groups include C 2 -C 6  alkenyl and C 2 -C 8  alkenyl groups. Alkenyl groups include, but are not limited to, for example, ethenyl, propenyl, butenyl, 1-methyl-2-buten-1-yl, heptenyl, octenyl and the like. 
         [0062]    The term “alkynyl”, as used herein, denotes a monovalent group derived from a hydrocarbon moiety by the removal of a single hydrogen atom wherein the hydrocarbon moiety has at least one carbon-carbon triple bond. Preferred alkynyl groups include C 2 -C 6  alkynyl and C 2 -C 8  alkynyl groups. Representative alkynyl groups include, but are not limited to, for example, ethynyl, 1-propynyl, 1-butynyl, heptynyl, octynyl and the like. 
         [0063]    The term “cycloalkyl”, as used herein, denotes a monovalent group derived from a monocyclic or polycyclic saturated carbocyclic ring, wherein the said polycyclic saturated carbocyclic ring is bi or tri cyclic group fused, bridged or spiro system, and one or more carbon atoms may be optionally oxo-substituted. Preferred cycloalkyl groups include C 3 -C 8  cycloalkyl and C 3 -C 12  cycloalkyl groups. Examples of C 3 -C 8 -cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentyl and cyclooctyl; and examples of C 3 -C 12 -cycloalkyl include, but not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, bicyclo[2.2.1]heptyl, bicyclo[3.1.0]hexyl, spiro[2.5]octyl, spiro[4.4]nonanyl. 
         [0064]    The term “cycloalkenyl” as used herein, denotes a monovalent group derived from a monocyclic or polycyclic carbocyclic ring having at least one carbon-carbon double bond, wherein the said polycyclic cycloalkenyl ring is bi or tri cyclic group fused, bridged or spiro system, and one or more carbon atoms may be optionally oxo-substituted. Preferred cycloalkenyl groups include C 3 -C 8  cycloalkenyl and C 3 -C 12  cycloalkenyl groups. Examples of C 3 -C 8 -cycloalkenyl include, but are not limited to, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, and the like; and examples of C 3 -C 12 -cycloalkenyl include, but not limited to, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, cycloheptenyl, bicyclo[2.2.1]hept-2-enyl, bicyclo[3.1.0]hex-2-enyl, spiro[2.5]oct-4-enyl, spiro[4.4]non-1-enyl, and the like. 
         [0065]    The term “aryl,” as used herein, refers to a mono- or bicyclic carbocyclic ring system having one or two aromatic rings including, but not limited to, phenyl, naphthyl, tetrahydronaphthyl, indanyl, indenyl and the like. 
         [0066]    The term “arylalkyl,” as used herein, refers to a C 1 -C 3  alkyl or C 1 -C 6  alkyl residue attached to an aryl ring. Examples include, but are not limited to, benzyl, phenethyl and the like. 
         [0067]    The term “heteroaryl,” as used herein, refers to a mono-, bi-, or tri-cyclic aromatic radical or ring having from five to ten ring atoms of which at least one ring atom is selected from S, O and N; wherein any N or S contained within the ring may be optionally oxidized. Preferred heteroaryl groups are monocyclic or bicyclic. Heteroaryl groups include, but are not limited to, pyridinyl, pyrazinyl, pyrimidinyl, pyrrolyl, pyrazolyl, imidazolyl, thiazolyl, oxazolyl, isooxazolyl, thiadiazolyl, oxadiazolyl, thiophenyl, furanyl, quinolinyl, isoquinolinyl, benzimidazolyl, benzooxazolyl, quinoxalinyl, and the like. 
         [0068]    The term “heteroarylalkyl,” as used herein, refers to a C 1 -C 3  alkyl or C 1 -C 6  alkyl residue attached to a heteroaryl ring. Examples include, but are not limited to, pyridinylmethyl, pyrimidinylethyl and the like. 
         [0069]    As used herein, the term “alkoxy” employed alone or in combination with other terms means, unless otherwise stated, an alkyl group having the designated number of carbon atoms connected to the rest of the molecule via an oxygen atom, such as, for example, methoxy, ethoxy, 1-propoxy, 2-propoxy (isopropoxy) and the higher homologs and isomers. Preferred alkoxy are (C 1 -C 3 ) alkoxy. 
         [0070]    The term “substituted” as used herein, refers to independent replacement of one, two, or three or more of the hydrogen atoms thereon with substituents including, but not limited to, deuterium, —F, —Cl, —Br, —I, —OH, protected hydroxy, —NO 2 , —CN, —NH 2 , N 3 , protected amino, alkoxy, thioalkoxy, oxo, C 1 -C 12 -alkyl, C 2 -C 12 -alkenyl, C 2 -C 12 -alkynyl, C 3 -C 12 -cycloalkyl, -halo-C 1 -C 12 -alkyl, -halo-C 2 -C 12 -alkenyl, -halo-C 2 -C 12 -alkynyl, -halo-C 3 -C 12 -cycloalkyl, —NH—C 1 -C 12 -alkyl, —NH—C 2 -C 12 -alkenyl, —NH—C 2 -C 12 -alkynyl, —NH—C 3 -C 12 -cycloalkyl, —NH-aryl, —NH-heteroaryl, —NH-heterocycloalkyl, -dialkylamino, -diarylamino, -diheteroarylamino, —O—C 2 -C 12 -alkenyl, —O—C 2 -C 12 -alkynyl, —O—C 3 -C 12 -cycloalkyl, —O-aryl, —O-heteroaryl, —O-heterocycloalkyl, —C(O)—C 1 -C 12 -alkyl, —C(O)—C 2 -C 12 -alkenyl, —C(O)—C 2 -C 12 -alkynyl, —C(O)—C 3 -C 12 -cycloalkyl, —C(O)-aryl, —C(O)-heteroaryl, —C(O)-heterocycloalkyl, —CONH 2 , —CONH—C 1 -C 12 -alkyl, —CONH—C 2 -C 12 -alkenyl, —CONH—C 2 -C 12 -alkynyl, —CONH—C 3 -C 12 -cycloalkyl, —CONH-aryl, —CONH-heteroaryl, —CONH-heterocycloalkyl, —OCO 2 —C 1 -C 12 -alkyl, —OCO 2 —C 2 -C 12 -alkenyl, —OCO 2 —C 2 -C 12 -alkynyl, —OCO 2 —C 3 -C 12 -cycloalkyl, —OCO 2 -aryl, —OCO 2 -heteroaryl, —OCO 2 -heterocycloalkyl, —OCONH 2 , —OCONH—C 1 -C 12 -alkyl, —OCONH—C 2 -C 12 -alkenyl, —OCONH—C 2 -C 12 -alkynyl, —OCONH—C 3 -C 12 -cycloalkyl, —OCONH-aryl, —OCONH— heteroaryl, —OCONH— heterocycloalkyl, —OCON(C 1 -C 12 -alkyl) 2 , —NHC(O)—C 1 -C 12 -alkyl, —NHC(O)—C 2 -C 12 -alkenyl, —NHC(O)—C 2 -C 12 -alkynyl, —NHC(O)—C 3 -C 12 -cycloalkyl, —NHC(O)-aryl, —NHC(O)-heteroaryl, —NHC(O)— heterocycloalkyl, —NHCO 2 —C 1 -C 12 -alkyl, —NHCO 2 —C 2 -C 12 -alkenyl, —NHCO 2 —C 2 -C 12 -alkynyl, —NHCO 2 —C 3 -C 12 -cycloalkyl, —NHCO 2 — aryl, —NHCO 2 — heteroaryl, —NHCO 2 -heterocycloalkyl, —NHC(O)NH 2 , —NHC(O)NH—C 1 -C 12 -alkyl, —NHC(O)NH—C 2 -C 12 -alkenyl, —NHC(O)NH—C 2 -C 12 -alkynyl, —NHC(O)NH—C 3 -C 12 -cycloalkyl, —NHC(O)NH-aryl, —NHC(O)NH-heteroaryl, —NHC(O)NH-heterocycloalkyl, NHC(S)NH 2 , —NHC(S)NH—C 1 -C 12 -alkyl, —NHC(S)NH—C 2 -C 12 -alkenyl, —NHC(S)NH—C 2 -C 12 -alkynyl, —NHC(S)NH—C 3 -C 12 -cycloalkyl, —NHC(S)NH-aryl, —NHC(S)NH-heteroaryl, —NHC(S)NH-heterocycloalkyl, —NHC(NH)NH 2 , —NHC(NH)NH—C 1 -C 12 -alkyl, —NHC(NH)NH—C 2 -C 12 -alkenyl, —NHC(NH)NH—C 2 -C 12 -alkynyl, —NHC(NH)NH—C 3 -C 12 -cycloalkyl, —NHC(NH)NH-aryl, —NHC(NH)NH-heteroaryl, —NHC(NH)NH-heterocycloalkyl, —NHC(NH)—C 1 -C 12 -alkyl, —NHC(NH)—C 2 -C 12 -alkenyl, —NHC(NH)—C 2 -C 12 -alkynyl, —NHC(NH)—C 3 -C 12 -cycloalkyl, —NHC(NH)-aryl, —NHC(NH)-heteroaryl, —NHC(NH)— heterocycloalkyl, —C(NH)NH—C 1 -C 12 -alkyl, —C(NH)NH—C 2 -C 12 -alkenyl, —C(NH)NH—C 2 -C 12 -alkynyl, —C(NH)NH—C 3 -C 12 -cycloalkyl, —C(NH)NH-aryl, —C(NH)NH-heteroaryl, —C(NH)NH-heterocycloalkyl, —S(O)—C 1 -C 12 -alkyl, —S(O)—C 2 -C 12 -alkenyl, —S(O)—C 2 -C 12 -alkynyl, —S(O)—C 3 -C 12 -cycloalkyl, —S(O)-aryl, —S(O)-heteroaryl, —S(O)-heterocycloalkyl —SO 2 NH 2 , —SO 2 NH—C 1 -C 12 -alkyl, —SO 2 NH—C 2 -C 12 -alkenyl, —SO 2 NH—C 2 -C 12 -alkynyl, —SO 2 NH—C 3 -C 12 -cycloalkyl, —SO 2 NH— aryl, —SO 2 NH— heteroaryl, —SO 2 NH-heterocycloalkyl, —NHSO 2 —C 1 -C 12 -alkyl, —NHSO 2 —C 2 -C 12 -alkenyl, —NHSO 2 —C 2 -C 12 -alkynyl, —NHSO 2 —C 3 -C 12 -cycloalkyl, —NHSO 2 -aryl, —NHSO 2 -heteroaryl, —NHSO 2 -heterocycloalkyl, —CH 2 NH 2 , —CH 2 SO 2 CH 3 , -aryl, -arylalkyl, -heteroaryl, -heteroarylalkyl, -heterocycloalkyl, —C 3 -C 12 -cycloalkyl, polyalkoxyalkyl, polyalkoxy, -methoxymethoxy, -methoxyethoxy, —SH, —S—C 1 -C 12 -alkyl, —S—C 2 -C 12 -alkenyl, —S—C 2 -C 12 -alkynyl, —S—C 3 -C 12 -cycloalkyl, —S-aryl, —S-heteroaryl, —S-heterocycloalkyl, methylthiomethyl, or -L′-R′, wherein L′ is C 1 -C 6 alkylene, C 2 -C 6 alkenylene or C 2 -C 6 alkynylene, and R′ is aryl, heteroaryl, heterocyclic, C 3 -C 12 cycloalkyl or C 3 -C 12 cycloalkenyl. It is understood that the aryls, heteroaryls, alkyls, and the like can be further substituted. In some cases, each substituent in a substituted moiety is additionally optionally substituted with one or more groups, each group being independently selected from —F, —Cl, —Br, —I, —OH, —NO 2 , —CN, or —NH 2 . 
         [0071]    In accordance with the invention, any of the aryls, substituted aryls, heteroaryls and substituted heteroaryls described herein, can be any aromatic group. Aromatic groups can be substituted or unsubstituted. 
         [0072]    It is understood that any alkyl, alkenyl, alkynyl, cycloalkyl and cycloalkenyl moiety described herein can also be an aliphatic group, an alicyclic group or a heterocyclic group. An “aliphatic group” is a non-aromatic moiety that may contain any combination of carbon atoms, hydrogen atoms, halogen atoms, oxygen, nitrogen or other atoms, and optionally contain one or more units of unsaturation, e.g., double and/or triple bonds. An aliphatic group may be straight chained, branched or cyclic and preferably contains between about 1 and about 24 carbon atoms, more typically between about 1 and about 12 carbon atoms. In addition to aliphatic hydrocarbon groups, aliphatic groups include, for example, polyalkoxyalkyls, such as polyalkylene glycols, polyamines, and polyimines, for example. Such aliphatic groups may be further substituted. It is understood that aliphatic groups may be used in place of the alkyl, alkenyl, alkynyl, alkylene, alkenylene, and alkynylene groups described herein. 
         [0073]    The term “alicyclic,” as used herein, denotes a monovalent group derived from a monocyclic or polycyclic saturated carbocyclic ring compound by the removal of a single hydrogen atom. Examples include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, bicyclo[2.2.1]heptyl, and bicyclo[2.2.2]octyl. Such alicyclic groups may be further substituted. 
         [0074]    The terms “heterocycloalkyl” and “heterocyclic” can be used interchangeably and refer to a non-aromatic ring or a bi- or tri-cyclic group fused, bridged, or spiro system, where: (i) each ring contains between one and three heteroatoms independently selected from oxygen, sulfur and nitrogen, (ii) each 5-membered ring has 0 to 1 double bonds and each 6-membered ring has 0 to 2 double bonds, (iii) the nitrogen and sulfur heteroatoms may optionally be oxidized, (iv) the nitrogen heteroatom may optionally be quaternized, (v) any of the above rings may be fused to a benzene ring, and (vi) the remaining ring atoms are carbon atoms which may be optionally oxo-substituted. Representative heterocycloalkyl groups include, but are not limited to, [1,3]dioxolane, pyrrolidinyl, pyrazolinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, piperidinyl, piperazinyl, oxazolidinyl, isoxazolidinyl, morpholinyl, thiazolidinyl, isothiazolidinyl, quinoxalinyl, pyridazinonyl, 2-azabicyclo[2.2.1]heptyl, 8-azabicyclo[3.2.1]octyl, 5-azaspiro[2.5]octyl, 1-oxa-7-azaspiro[4.4]nonanyl, and tetrahydrofuryl. Such heterocyclic groups may be further substituted to give substituted heterocyclic. Heteroaryl or heterocyclic groups can be C-attached or N-attached (where possible). 
         [0075]    It will be apparent that in various embodiments of the invention, the substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, and heterocycloalkyl are intended to be monovalent or divalent. Thus, alkylene, alkenylene, and alkynylene, cycloaklylene, cycloalkenylene, cycloalkynylene, arylene, arylalkylene, heteroarylene, heteroarylalkylene and heterocycloalkylene groups are to be included in the above definitions, and are applicable to provide the Formulas herein with proper valency. 
         [0076]    The terms “halo” and “halogen,” as used herein, refer to an atom selected from fluorine, chlorine, bromine and iodine. 
         [0077]    The term “hydrogen” includes hydrogen and deuterium. In addition, the recitation of an atom includes other isotopes of that atom so long as the resulting compound is pharmaceutically acceptable. 
         [0078]    In certain embodiments, the compounds of each formula herein include isotopically labelled compounds. An “isotopically labelled compound” is a compound in which at least one atomic position is enriched in a specific isotope of the designated element to a level which is significantly greater than the natural abundance of that isotope. For example, one or more hydrogen atom positions in a compound can be enriched with deuterium to a level which is significantly greater than the natural abundance of deuterium, for example, enrichment to a level of at least 1%, preferably at least 20% or at least 50%. Such a deuterated compound may, for example, be metabolized more slowly than its non-deuterated analog, and therefore exhibit a longer half-life when administered to a subject. Such compounds can synthesize using methods known in the art, for example by employing deuterated starting materials. Unless stated to the contrary, isotopically labelled compounds are pharmaceutically acceptable. 
         [0079]    When the compounds described herein contain one or more asymmetric centers they give rise to enantiomers, diastereomers, and other stereoisomeric forms that may be defined, in terms of absolute stereochemistry, as (R)- or (S)-, or as (D)- or (L)- for amino acids. The present invention is meant to include all such possible isomers, as well as their racemic and optically pure forms. Optical isomers may be prepared from their respective optically active precursors by the procedures described above, or by resolving the racemic mixtures. The resolution can be carried out in the presence of a resolving agent, by chromatography or by repeated crystallization or by some combination of these techniques, which are known to those skilled in the art. Further details regarding resolutions can be found in Jacques, et al.,  Enantiomers, Racemates, and Resolutions  (John Wiley &amp; Sons, 1981). When the compounds described herein contain olefinic double bonds or other centers of geometric asymmetry, and unless specified otherwise, it is intended that the compounds include both E and Z geometric isomers. Likewise, all tautomeric forms are also intended to be included. The configuration of any carbon-carbon double bond appearing herein is selected for convenience only and is not intended to designate a particular configuration unless the text so states; thus a carbon-carbon double bond depicted arbitrarily herein as trans may be cis, trans, or a mixture of the two in any proportion. 
         [0080]    The term “subject” as used herein refers to a mammal. A subject therefore refers to, for example, dogs, cats, horses, cows, pigs, guinea pigs, and the like. Preferably the subject is a human. When the subject is a human, the subject may be referred to herein as a patient. 
         [0081]    As used herein, the term “pharmaceutically acceptable salt” refers to those salts of the compounds formed by the process of the present invention which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable salts are well known in the art. 
         [0082]    Berge, et al. describes pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 66: 1-19 (1977). The salts can be prepared in situ during the final isolation and purification of the compounds of the invention, or separately by reaction of the free base function with a suitable organic acid. Examples of pharmaceutically acceptable salts include, but are not limited to, nontoxic acid addition salts e.g., salts of an amino group formed with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid and perchloric acid or with organic acids such as acetic acid, maleic acid, tartaric acid, citric acid, succinic acid or malonic acid or by using other methods used in the art such as ion exchange. Other pharmaceutically acceptable salts include, but are not limited to, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate salts, and the like. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Further pharmaceutically acceptable salts include, when appropriate, nontoxic ammonium, quaternary ammonium, and amine cations formed using counterions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, alkyl having from 1 to 6 carbon atoms, sulfonate and aryl sulfonate. 
         [0083]    The term “amino protecting group,” as used herein, refers to a labile chemical moiety which is known in the art to protect an amino group against undesired reactions during synthetic procedures. After said synthetic procedure(s) the amino protecting group as described herein may be selectively removed. Amino protecting groups as known in the are described generally in T. H. Greene and P. G. M. Wuts,  Protective Groups in Organic Synthesis,  3rd edition, John Wiley &amp; Sons, New York (1999). Examples of amino protecting groups include, but are not limited to, t-butoxycarbonyl, 9-fluorenylmethoxycarbonyl, benzyloxycarbonyl, and the like. 
         [0084]    As used herein, the term “pharmaceutically acceptable ester” refers to esters of the compounds formed by the process of the present invention which hydrolyze in vivo and include those that break down readily in the human body to leave the parent compound or a salt thereof. Suitable ester groups include, for example, those derived from pharmaceutically acceptable aliphatic carboxylic acids, particularly alkanoic, alkenoic, cycloalkanoic and alkanedioic acids, in which each alkyl or alkenyl moiety advantageously has not more than 6 carbon atoms. Examples of particular esters include, but are not limited to, formates, acetates, propionates, butyrates, acrylates and ethyl succinates. 
         [0085]    The term “pharmaceutically acceptable prodrugs” as used herein refers to those prodrugs of the compounds formed by the process of the present invention which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals with undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable benefit/risk ratio, and effective for their intended use, as well as the zwitterionic forms, where possible, of the compounds of the present invention. “Prodrug”, as used herein means a compound, which is convertible in vivo by metabolic means (e.g. by hydrolysis) to afford any compound delineated by the Formulae of the instant invention. Various forms of prodrugs are known in the art, for example, as discussed in Bundgaard, (ed.),  Design of Prodrugs , Elsevier (1985); Widder, et al. (ed.),  Methods in Enzymology , Vol. 4, Academic Press (1985); Krogsgaard-Larsen, et al., (ed). “Design and Application of Prodrugs,  Textbook of Drug Design and Development , Chapter 5, 113-191 (1991); Bundgaard, et al.,  Journal of Drug Deliver Reviews,  8:1-38(1992); Bundgaard, J. of  Pharmaceutical Sciences,  77:285 et seq. (1988); Higuchi and Stella (eds.) Prodrugs as Novel Drug Delivery Systems,  American Chemical Society  (1975); and Bernard Testa &amp; Joachim Mayer, “Hydrolysis In Drug And Prodrug Metabolism: Chemistry, Biochemistry And Enzymology,” John Wiley and Sons, Ltd. (2002). 
         [0086]    The term “treating”, as used herein, means relieving, lessening, reducing, eliminating, modulating, or ameliorating, i.e. causing regression of the disease state or condition. Treating can also include inhibiting, i.e. arresting the development, of an existing disease state or condition, and relieving or ameliorating, i.e. causing regression of an existing disease state or condition, for example when the disease state or condition may already be present. 
         [0087]    The term “preventing”, as used herein means, to completely or almost completely stop a disease state or condition, from occurring in a patient or subject, especially when the patient or subject is predisposed to such or at risk of contracting a disease state or condition. 
         [0088]    Additionally, the compounds of the present invention, for example, the salts of the compounds, can exist in either hydrated or unhydrated (the anhydrous) form or as solvates with other solvent molecules. Nonlimiting examples of hydrates include monohydrates, dihydrates, etc. Nonlimiting examples of solvates include ethanol solvates, acetone solvates, etc. 
         [0089]    “Solvates” means solvent addition forms that contain either stoichiometric or non-stoichiometric amounts of solvent. Some compounds have a tendency to trap a fixed molar ratio of solvent molecules in the crystalline solid state, thus forming a solvate. If the solvent is water the solvate formed is a hydrate, when the solvent is alcohol, the solvate formed is an alcoholate. Hydrates are formed by the combination of one or more molecules of water with one of the substances in which the water retains its molecular state as H 2 O, such combination being able to form one or more hydrate. 
         [0090]    As used herein, the term “analog” refers to a chemical compound that is structurally similar to another but differs slightly in composition (as in the replacement of one atom by an atom of a different element or in the presence of a particular functional group, or the replacement of one functional group by another functional group). Thus, an analog is a compound that is similar to or comparable in function and appearance to the reference compound. 
         [0091]    The term “aprotic solvent,” as used herein, refers to a solvent that is relatively inert to proton activity, i.e., not acting as a proton-donor. Examples include, but are not limited to, hydrocarbons, such as hexane and toluene, for example, halogenated hydrocarbons, such as, for example, methylene chloride, ethylene chloride, chloroform, and the like, heterocyclic compounds, such as, for example, tetrahydrofuran and N-methylpyrrolidinone, and ethers such as diethyl ether, bis-methoxymethyl ether. Such solvents are well known to those skilled in the art, and individual solvents or mixtures thereof may be preferred for specific compounds and reaction conditions, depending upon such factors as the solubility of reagents, reactivity of reagents and preferred temperature ranges, for example. Further discussions of aprotic solvents may be found in organic chemistry textbooks or in specialized monographs, for example:  Organic Solvents Physical Properties and Methods of Purification,  4th ed., edited by John A. Riddick et al., Vol. II, in the  Techniques of Chemistry Series , John Wiley &amp; Sons, NY, 1986. 
         [0092]    The terms “protogenic organic solvent” or “protic solvent” as used herein, refer to a solvent that tends to provide protons, such as an alcohol, for example, methanol, ethanol, propanol, isopropanol, butanol, t-butanol, and the like. Such solvents are well known to those skilled in the art, and individual solvents or mixtures thereof may be preferred for specific compounds and reaction conditions, depending upon such factors as the solubility of reagents, reactivity of reagents and preferred temperature ranges, for example. Further discussions of protogenic solvents may be found in organic chemistry textbooks or in specialized monographs, for example:  Organic Solvents Physical Properties and Methods of Purification,  4th ed., edited by John A. Riddick et al., Vol. II, in the  Techniques of Chemistry Series , John Wiley &amp; Sons, NY, 1986. 
         [0093]    Combinations of substituents and variables envisioned by this invention are only those that result in the formation of stable compounds. The term “stable”, as used herein, refers to compounds which possess stability sufficient to allow manufacture and which maintains the integrity of the compound for a sufficient period of time to be useful for the purposes detailed herein (e.g., therapeutic or prophylactic administration to a subject). 
         [0094]    The synthesized compounds can be separated from a reaction mixture and further purified by a method such as column chromatography, high pressure liquid chromatography, or recrystallization. Additionally, the various synthetic steps may be performed in an alternate sequence or order to give the desired compounds. In addition, the solvents, temperatures, reaction durations, etc. delineated herein are for purposes of illustration only and variation of the reaction conditions can produce the desired isoxazole products of the present invention. Synthetic chemistry transformations and protecting group methodologies (protection and deprotection) useful in synthesizing the compounds described herein include, for example, those described in R. Larock,  Comprehensive Organic Transformations , VCH Publishers (1989); T. W. Greene and P. G. M. Wuts,  Protective Groups in Organic Synthesis,  2d. Ed., John Wiley and Sons (1991); L. Fieser and M. Fieser,  Fieser and Fieser&#39;s Reagents for Organic Synthesis , John Wiley and Sons (1994); and L. Paquette, ed.,  Encyclopedia of Reagents for Organic Synthesis , John Wiley and Sons (1995). 
         [0095]    The compounds of this invention may be modified by appending various functionalities via synthetic means delineated herein to enhance selective biological properties. Such modifications include those which increase biological penetration into a given biological system (e.g., blood, lymphatic system, central nervous system), increase oral availability, increase solubility to allow administration by injection, alter metabolism and alter rate of excretion. 
       Pharmaceutical Compositions 
       [0096]    The pharmaceutical compositions of the present invention comprise a therapeutically effective amount of a compound of the present invention formulated together with one or more pharmaceutically acceptable carriers. As used herein, the term “pharmaceutically acceptable carrier” means a non-toxic, inert solid, semi-solid or liquid filler, diluent, encapsulating material or formulation auxiliary of any type. Some examples of materials which can serve as pharmaceutically acceptable carriers are sugars such as lactose, glucose and sucrose; starches such as corn starch and potato starch; cellulose and its derivatives such as sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate; powdered tragacanth; malt; gelatin; talc; excipients such as cocoa butter and suppository waxes; oils such as peanut oil, cottonseed oil; safflower oil; sesame oil; olive oil; corn oil and soybean oil; glycols; such a propylene glycol; esters such as ethyl oleate and ethyl laurate; agar; buffering agents such as magnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline; Ringer&#39;s solution; ethyl alcohol, and phosphate buffer solutions, as well as other non-toxic compatible lubricants such as sodium lauryl sulfate and magnesium stearate, as well as coloring agents, releasing agents, coating agents, sweetening, flavoring and perfuming agents, preservatives and antioxidants can also be present in the composition, according to the judgment of the formulator. The pharmaceutical compositions of this invention can be administered to humans and other animals orally, rectally, parenterally, intracisternally, intravaginally, intraperitoneally, topically (as by powders, ointments, or drops), buccally, or as an oral or nasal spray. 
         [0097]    The pharmaceutical compositions of this invention may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir, preferably by oral administration or administration by injection. The pharmaceutical compositions of this invention may contain any conventional non-toxic pharmaceutically-acceptable carriers, adjuvants or vehicles. In some cases, the pH of the formulation may be adjusted with pharmaceutically acceptable acids, bases or buffers to enhance the stability of the formulated compound or its delivery form. The term parenteral as used herein includes subcutaneous, intracutaneous, intravenous, intramuscular, intraarticular, intraarterial, intrasynovial, intrasternal, intrathecal, intralesional and intracranial injection or infusion techniques. 
         [0098]    Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethylformamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof. Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents. 
         [0099]    Injectable preparations, for example, sterile injectable aqueous or oleaginous suspensions may be formulated according to the known art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution, suspension or emulsion in a nontoxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer&#39;s solution, U.S.P. and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil can be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid are used in the preparation of injectables. 
         [0100]    The injectable formulations can be sterilized, for example, by filtration through a bacterial-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium prior to use. 
         [0101]    In order to prolong the effect of a drug, it is often desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the drug then depends upon its rate of dissolution, which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally administered drug form is accomplished by dissolving or suspending the drug in an oil vehicle. Injectable depot forms are made by forming microencapsule matrices of the drug in biodegradable polymers such as polylactide-polyglycolide. Depending upon the ratio of drug to polymer and the nature of the particular polymer employed, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides). Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions which are compatible with body tissues. 
         [0102]    Compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the compounds of this invention with suitable non-irritating excipients or carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at ambient temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active compound. 
         [0103]    Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is mixed with at least one inert, pharmaceutically acceptable excipient or carrier such as sodium citrate or dicalcium phosphate and/or: a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents. 
         [0104]    Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like. 
         [0105]    The active compounds can also be in micro-encapsulated form with one or more excipients as noted above. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings, release controlling coatings and other coatings well known in the pharmaceutical formulating art. In such solid dosage forms the active compound may be admixed with at least one inert diluent such as sucrose, lactose or starch. Such dosage forms may also comprise, as is normal practice, additional substances other than inert diluents, e.g., tableting lubricants and other tableting aids such a magnesium stearate and microcrystalline cellulose. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes. 
         [0106]    Dosage forms for topical or transdermal administration of a compound of this invention include ointments, pastes, creams, lotions, gels, powders, solutions, sprays, inhalants or patches. The active component is admixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives or buffers as may be required. Ophthalmic formulation, ear drops, eye ointments, powders and solutions are also contemplated as being within the scope of this invention. 
         [0107]    The ointments, pastes, creams and gels may contain, in addition to an active compound of this invention, excipients such as animal and vegetable fats, oils, waxes, paraffins, starch, tragacanth, cellulose derivatives, polyethylene glycols, silicones, bentonites, silicic acid, talc and zinc oxide, or mixtures thereof. 
         [0108]    Powders and sprays can contain, in addition to the compounds of this invention, excipients such as lactose, talc, silicic acid, aluminum hydroxide, calcium silicates and polyamide powder, or mixtures of these substances. Sprays can additionally contain customary propellants such as chlorofluorohydrocarbons. 
         [0109]    Transdermal patches have the added advantage of providing controlled delivery of a compound to the body. Such dosage forms can be made by dissolving or dispensing the compound in the proper medium. Absorption enhancers can also be used to increase the flux of the compound across the skin. The rate can be controlled by either providing a rate controlling membrane or by dispersing the compound in a polymer matrix or gel. 
         [0110]    Unless otherwise defined, all technical and scientific terms used herein are accorded the meaning commonly known to one with ordinary skill in the art. All publications, patents, published patent applications, and other references mentioned herein are hereby incorporated by reference in their entirety. 
       Abbreviations 
       [0111]    Abbreviations which have been used in the descriptions of the schemes and the examples that follow are: 
         [0000]    BOP-C 1  for bis(2-oxo-3-oxazolidinyl)phosphinic chloride;
 
CDI for carbonyldiimidazole;
 
DBU for 1,8-diazabicycloundec-7-ene;
 
       DCC for N,N-dicyclohexylcarbodiimide; 
       [0112]    DCM for dichloromethane; 
       DMAP for N,N-dimethylaminopyridine; 
       [0113]    DMF for N,N-dimethyl formamide;
 
DPPA for diphenylphosphoryl azide;
 
EDC for 1-(3-diethylaminopropyl)-3-ethylcarbodiimide hydrochloride;
 
Et 3 N for triethylamine;
 
EtOAc for ethyl acetate;
 
HATU for 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxid hexafluorophosphate;
 
HCl for hydrochloric acid;
 
PyAOP for 7-azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate;
 
PyBOP for benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate;
 
rt for room temperature;
 
TFFH for tetramethylfluoroformamidinium hexafluorophosphate;
 
THF for tetrahydrofuran.
 
       Synthetic Methods 
       [0114]    The compounds and processes of the present invention will be better understood in connection with the following synthetic schemes that illustrate the methods by which the compounds of the invention may be prepared, which are intended as an illustration only and not to limit the scope of the invention. Various changes and modifications to the disclosed embodiments will be apparent to those skilled in the art and such changes and modifications including, without limitation, those relating to the chemical structures, substituents, derivatives, and/or methods of the invention may be made without departing from the spirit of the invention and the scope of the appended claims. 
         [0115]    Novel isoxazole compounds of formula (I) can be prepared from the compounds of formula (I-1), wherein R 1 , R 2 , Y, A, and R 3  are defined as previously, according to the following schemes and examples, or modifications thereof, using readily available starting materials, reagents, intermediates and conventional synthetic procedures. The compound of formula (I-1) can be synthesized following literature procedures as described in WO2008/025540; WO2009/149795, WO2007/140183; WO2004/048349 and references cited therein. 
         [0116]    For example, novel acyl sulfonamide compounds of formula (Ic) can be prepared from the compounds of formula (I-1) as depicted in Scheme 1. 
         [0117]    Compounds of formula (I-1) can couple together in suitable coupling conditions (coupling reagent, base, solvent and temperature, etc) to give compounds of formula (Ic). The coupling reagent can be selected from, but not limited to, DCC, EDC, CDI, di-isopropyl carbodiimide, BOP-C 1 , PyBOP, PyAOP, TFFH and HATU. Suitable bases include, but are not limited to, triethylamine, diisopropylethylamine, DBU, N-methylmorpholine and DMAP. The coupling reaction can be carried out in an aprotic solvent such as, but not limited to, CH 2 Cl 2 , DMF or THF. The reaction temperature can vary from 0° C. to 80° C. 
         [0118]    It may be necessary to protect certain functionalities, such as OH, NH, and NH 2  groups, in formula (I-1) and formula (I-2) depending the nature of R 1 , R 2 , Y, A, and R 9 . The protecting groups need to be deprotected after coupling reaction. Protecting and deprotecting these functionalities should be within the expertise of one skilled in the art. See e.g. P. G. M. Wuts and T. W. Greene,  Protective Groups in Organic Synthesis,  Fourth Edition, John Wiley and Sons, 2006, hereafter Greene. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0119]    Scheme 2 illustrates the preparation of the compounds of formula (Ib) from the compounds of formula (I-1), wherein R 1 , R 2 , Y, A, and R 8  are defined as previously. 
         [0120]    Thus, the compound of formula (I-1) is coupled with an amino ester compound of formula (I-5) under suitable amide coupling conditions to give the compound of formula (I-6). The coupling reagent can be selected from, but not limited to, DCC, EDC, CDI, di-isopropyl carbodiimide, BOP-Cl, PyBOP, PyAOP, TFFH and HATU. Suitable bases include, but are not limited to, triethylamine, diisopropylethylamine, DBU, N-methylmorpholine and DMAP. The coupling reaction can be carried out in an aprotic solvent such as, but not limited to, CH 2 Cl 2 , DMF or THF. The reaction temperature can vary from 0° C. to 80° C. Hydrolysis of the methyl ester of the compound of formula (I-6) can afford the compound of formula (I-7). The reagent for hydrolysis can be, but not limited to, LiOH, NaOH and KOH. The solvent can be, but not limited to THF, MeOH, EtOH, dioxane, water or mixture of above. The reaction temperature can vary from 0° C. to 80° C. Further coupling of the compound of formula (I-7) with the sulfonamide compound of formula (I-3), followed by appropriate functional group deprotections if needed, affords the compound of formula (Ib), using the procedures and conditions similar to ones described for the synthesis of the compounds of formula (Ic) in Scheme 1. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0121]    Scheme 3 illustrates the preparation of the compound of formula (Ia) from the compound of formula (I-1), wherein R 1 , R 2 , Y, A, and R 8  are defined as previously. 
         [0122]    Thus, the compound of formula (I-1) is converted to the acyl azide compound of formula (I-10) using a suitable reagent such as, but not limited to, DPPA. The reaction solvent can be, but not limited to, THF, DCM, DCE and toluene. The reaction temperature is from 0° C.˜40° C. Further rearrangement of the acyl azide compound of formula (I-10) at the elevated temperature, such as, but not limited to, 60-120° C., generates the isocyanate intermediate, which then can react with sulfonamide compound of formula (I-3) followed by removal of protecting groups if necessary to afford the sulfonylurea compound of formula (Ia). 
         [0000]    
       
                 
         
             
             
         
       
     
       EXAMPLES 
       [0123]    The compounds and processes of the present invention will be better understood in connection with the following examples, which are intended as an illustration only and not limiting of the scope of the invention. Various changes and modifications to the disclosed embodiments will be apparent to those skilled in the art and such changes and modifications including, without limitation, those relating to the chemical structures, substituents, derivatives, formulations and/or methods of the invention may be made without departing from the spirit of the invention and the scope of the appended claims. 
       Example 1 
       [0124]    
       
                 
         
             
             
         
       
     
         [0125]    A solution of compound 2 (12 mg, 0.02 mmol), cyclopropanesulfonamide (4.9 mg, 0.041 mmol), EDC (7.8 mg, 0.04 mmol), and DMAP (5.0 mg, 0.04 mmol) in DCM (1.0 mL) was stirred at rt for 16 h, then quenched with brine, and extracted with EtOAc. The combined organic layers were washed with brine and concentrated. The residue was purified by chromatography on silica gel using hexane/acetone (100/0 to 50/50, 10 min) to give desired product 1 as a white solid (10 mg, 71%), LC-MS, ES − : 693.09 (M-1). 
       Example 2 
       [0126]    
       
                 
         
             
             
         
       
     
         [0127]    A solution of compound 2 (12 mg, 0.02 mmol), 4-(tert-butyl)benzenesulfonamide (8.64 mg, 0.041 mmol, EDC (7.8 mg, 0.04 mmol), and DMAP (5.0 mg, 0.04 mmol) in DCM was stirred at RT for 16 h, then quenched with brine, and extracted with EtOAc. The combined organic layers were washed with brine and concentrated. The residue was purified by chromatography on silica gel using hexane/acetone (100/0 to 50/50, 10 min) to give desired example 2 as a white solid (12 mg, 75%). LC-MS, ES − : 785.16 (M-1). 
       Example 3 
       [0128]    
       
                 
         
             
             
         
       
     
         [0129]    A solution of compound 2 (59 mg, 0.1 mmol), N,N-dimethylsulfamide (24.7 mg, 0.2 mmol), EDC (38.2 mg, 0.200 mmol), and DMAP (24.3 mg, 0.200 mmol) in DCM (2.0 mL) was stirred at rt for 16 h, then quenched with brine, and extracted with EtOAc. The combined organic layers were washed with brine and concentrated. The residue was purified by chromatography on silica gel using hexane/acetone (100/0 to 50/50, 10 min) to give product 6 as a white solid (45 mg, 65%). LC-MS, ES − : 696.11 (M-1). 
       Assays 
     Human FXR (NR1H4) Assay 
       [0130]    Determination of a ligand mediated Gal4 promoter driven transactivation to quantify ligand binding mediated activation of FXR. FXR Reporter Assay kit purchased from Indigo Bioscience (Catalogue number: IB00601) to determine the potency and efficacy of compound developed by Enanta that can induce FXR activation. The principle application of this reporter assay system is to quantify functional activity of human FXR. The assay utilizes non-human mammalian cells, CHO (Chinese hamster ovary) cells engineered to express human NR1H4 protein (referred to as FXR). Reporter cells also incorporate the cDNA encoding beetle luciferase which catalyzes the substrates and yields photon emission. Luminescence intensity of the reaction is quantified using a plate-reading luminometer, Envision. Reporter Cells include the luciferase reporter gene functionally linked to an FXR responsive promoter. Thus, quantifying changes in luciferase expression in the treated reporter cells provides a sensitive surrogate measure of the changes in FXR activity. EC 50  and efficacy (normalize to CDCA set as 100%) is determined by XLFit. The assay is according to the manufacturer&#39;s instructions. In brief, the assay was performed in white, 96 well plates using final volume of 100 μl containing cells with different doses of compounds. Retrieve Reporter Cells from −80° C. storage. Perform a rapid thaw of the frozen cells by transferring a 10 ml volume of 37° C. cell recovery medium into the tube of frozen cells. Recap the tube of Reporter Cells and immediately place it in a 37° C. water bath for 5-10 minutes. Retrieve the tube of Reporter Cell Suspension from the water bath. Sanitize the outside surface of the tube with a 70% alcohol swab, and then transfer it into the cell culture hood. Dispense 90 μl of cell suspension into each well of the 96-well Assay Plate. Transfer the plate into 37° C. incubator, allowing the cells adherent to the bottom of the well. Dilute compounds in Dilution Plate (DP), and administrate to cells at Assay Plate (AP). DMSO content of the samples was kept at 0.2%. Cells were incubated for additional 22 hours before luciferase activities were measured. Thirty minutes before intending to quantify FXR activity, remove Detection Substrate and Detection Buffer from the refrigerator and place them in a low-light area so that they may equilibrate to room temperature. Remove the plate&#39;s lid and discard all media contents by ejecting it into an appropriate waste container. Gently tap the inverted plate onto a clean absorbent paper towel to remove residual droplets. Cells will remain tightly adhered to well bottoms. Add 100 μl of luciferase detection reagent to each well of the assay plate. Allow the assay plate to rest at room temperature for at least 5 minutes following the addition of LDR. Set the instrument (Envision) to perform a single 5 second “plate shake” prior to reading the first assay well. Read time may be 0.5 second (500 mSec) per well. EC 50  and Efficacy (normalize to CDCA set as 100%) is determined by XLFit. 
         [0131]    To assess the FXR agonistic potency of the example compounds as well as for reference compound, potency ranges were determined in the Human FXR (NR1H4) Assay as listed below in Table 1. The efficacy was normalized to CDCA set as 100%. (A: EC50&lt;0.1 μM; B: 0.1 μM&lt;EC50&lt;1.0 μM; C: 1.0 μM&lt;EC50&lt;10 μM; D: EC50&gt;10 μM). 
         [0000]    
       
         
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Example 
                 EC50 (μM) 
                 Efficacy (%) 
               
               
                   
               
             
             
               
                 CDCA 
                 D 
                 100 
               
               
                 1 
                 B 
                 145 
               
               
                 2 
                 C 
                 108 
               
               
                 3 
                 A 
                 153 
               
               
                   
               
             
          
         
       
     
         [0132]    While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
The present invention provides compounds of Formula I: 
     
       
                 
         
             
             
         
       
     
     and pharmaceutically acceptable salts thereof, pharmaceutical compositions comprising these compounds and methods of using these compounds to treat or prevent a disease or disorder mediated as FXR modulators. Specifically, the present invention relates to isoxazole derivatives useful as agonists for FXR, and methods for their preparation and use.