PIPERIDINYL ARYLSULFONE DERIVATIVES AS MODULATORS OF SECRETED FRIZZLED RELATED PROTEIN- 1

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 60/865,251, filed November 10, 2006, which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

[0002] The present invention relates to novel piperidinyl arylsulfonamide derivatives that act, for example, as modulators of secreted frizzled-related protein- 1. The present invention also relates to processes for the preparation of piperidinyl arylsulfonamide derivatives, pharmaceutical compositions containing them and to their use in treating various diseases and disorders, including osteoporosis, arthritis, chronic obstructive pulmonary disease, cartilage defects, bone fractures, leiomyoma, acute myeloid leukemia, wound healing, prostate cancer, as well as autoimmune inflammatory disorders such as Graves ophthalmopathy, and combinations thereof.

BACKGROUND OF THE INVENTION

[0003] Bone remodeling, the process by which the adult human skeleton is continuously renewed, is carried out by osteoclasts and osteoblasts, two specialized cell types that originate from hematopoietic and mesenchymal progenitors of the bone marrow, respectively. A continuous and orderly supply of these cells is believed to be essential for skeletal homeostasis, as increased or decreased production of osteoclasts or osteoblasts and/or changes in the rate of their apoptosis are largely responsible for the imbalance between bone resorption and formation that underlies several systemic or localized bone diseases. For example, enhanced osteoclast activity has been found to play a major role in the pathogenesis of postmenopausal osteoporosis, Paget' s disease, lytic bone metastases, multiple myeloma, hyperparathyroidism, rheumatoid arthritis, periodontitis, and hypercalcemia of malignancy.

[0004] Numerous genes and gene families (and the polypeptides encoded by them) that participate in the regulation of bone cell production and apoptosis have been identified. Wnt proteins have been identified as a family of growth factors consisting of more than a dozen structurally related molecules that are involved in the regulation of fundamental biological processes such as apoptosis, adipogenesis, embryogenesis, organogenesis, morphogenesis and tumorigenesis (Nusse and Varmus, Cell 1992, 69:1073-1087). Wnt polypeptides are multipotent factors and have biological activities similar to those of other secretory proteins such as transforming growth factor (TGF)-β, fibroblast growth factors (FGFs), nerve growth factor (NGF), and bone morphogenetic proteins (BMPs).

[0005] Studies indicate that certain Wnt proteins interact with a family of proteins named "frizzled" that act as receptors for Wnt proteins or as components of a Wnt receptor complex (in Moon et al, Cell 1997, 88:725-728; Barth et al, Curr. Opin. Cell Biol. 1997, 9:683- 690). Frizzled proteins contain an amino terminal signal sequence for secretion, a cysteine-rich domain (CRD) that is thought to bind Wnt, seven putative transmembrane domains that resemble a G-protein coupled receptor, and a cytoplasmic carboxyl terminus. The Frizzled receptors form a signaling complex with another family of membrane receptors known as the low-density lipoprotein (LDL) receptor-related proteins (LRP) (in Logan & Nusse, Annual Review of Cell & Developmental Biology 2004, 20:781-810; Moon et al, Nature Reviews Genetics 2004, 5:691- 701).

[0006] The first secreted frizzled-related protein (SFRP) was named "Frzb" (for "frizzled motif in bone development") and was purified and cloned from bovine articular

cartilage extracts based on its ability to stimulate in vivo chondrogenic activity in rats (Hoang et al., J. Biol. Chem. 1996, 271 :26131-26137; Jones & iom&τy, Bioessays 2002, 24:811-820). The human homologue of the bovine gene has also been cloned. Unlike the frizzled proteins, however, Frzb does not contain a serpentine transmembrane domain, and appears to be a secreted receptor for Wnt. The Frzb cDNA encodes a 325 amino acid/36,000 dalton protein and is predominantly expressed in the appendicular skeleton. The highest level of expression is in developing long bones and corresponds to epiphyseal chondroblasts; expression declines and disappears toward the ossification center.

[0007] Studies indicate that SFRPs participate in apoptosis. Some SFRPs have thus been identified as "SARPs" for secreted apoptosis related proteins. Additional members of the SFRP family have been identified, and have been shown to be antagonists of Wnt action. There are currently at least five known human SFRP/SARP genes: SFRP-l/FrzA/FRP-l/SARP-2, SFRP-2/SDF-5/SARP-1, SFRP-3/Frzb-l/FrzB/Fritz, SFRP-4 and SFRP-5/SARP-3 (Leimeister et al, Mechanisms of Development 1998, 75:29-42). Secreted frizzled related protein-1 (SFRP- 1) is a Wnt antagonist and is expressed in osteoblasts and osteocytes as well as fibroblasts. Although the precise role that SARPs/SFRPs play in apoptosis is not yet clear, these proteins appear to either suppress or enhance the programmed cell death process. Deletion of SFRP-I in mice has been shown to lead to decreased osteoblastOsteocyte apoptosis and to increased bone formation. (Bodine, P.V.N, et al., MoI. Endocrinol. , 2004, 18(5) 1222-1237.) Deletion of SFRP-I in mice has also been shown to lead to an acceleration of chondrocyte differentiation. (Gaur, T., et al, J. Cell. Physiol., 2006, 208(1) 87-96.) Modulation of SFRP-I with an anti- SFRP-I antibody has been shown to enhance new connective tissue formation resulting in increases in palatal wound healing (Li, C. H. and Amar, S. J. Dent. Research, 2006, 85(4), 374- 378. Overexpression of SFRP-I has also been implicated in autoimmune inflammatory disorders such as Graves Ophthalmopathy, and combinations thereof by stimulating a pathogenic process of adipogensis (Kumar, S., et. al, J. Clin. Endocrinol. Metab., 2005, 90, 4730-4735).

[0008] A need exists in the art for the identification of modulators of SFRP-I that can be used as novel agents for the treatment of bone disorders or bone fractures, including bone resorption disorders such as osteoporosis, and for regulation of bone formation in humans or for other diseases and disorders, such as arthritis, chronic obstructive pulmonary disease, cartilage defects, leiomyoma, acute myeloid leukemia, wound healing, prostate cancer, as well as autoimmune inflammatory disorders such as Graves ophthalmopathy, and combinations thereof.

SUMMARY OF THE INVENTION

[0009] The present invention relates to certain piperidinyl arylsulfonamide derivatives and to their use, for example, in medical treatment. In one aspect, the invention relates piperidinyl arylsulfonamide derivatives that act as modulators of secreted frizzled related protein- 1. The compounds can be used, for example, to treat various diseases and disorders, including osteoporosis, arthritis, chronic obstructive pulmonary disease, cartilage defects, bone fractures, leiomyoma, acute myeloid leukemia, wound healing, prostate cancer, as well as autoimmune inflammatory disorders such as Graves ophthalmopathy, and combinations thereof.

[0010] In certain aspects, the present invention is directed to compounds of Formula (1):

or pharmaceutically acceptable salts thereof, wherein:

Ri is O, S, SO ₂ , or NR ₅ ;

R ₂ is Ci -C ₃ alkylene;

R ₃ is CpC ₆ alkyl, C ₁ -C ₃ perfluoroalkyl, Ci -C ₃ perfluoroalkoxy, C ₁ -C ₃ alkoxy, halogen, or CN;

R ₄ is hydrogen, Ci-C ₆ alkyl, -(CH ₂ )o- ₃ -aryl, -(CH ₂ ) _0-3 -substituted aryl, -(CH ₂ )o-3- heteroaryl, -(CH ₂ ) ₀ - ₃ -substituted heteroaryl, -SO ₂ -Ci-C ₆ alkyl, -SO ₂ -(CH ₂ ) ₀ - ₃ -aryl, -SO ₂ -(CH ₂ ) ₀ . ₃ - substituted aryl, -SO ₂ -(CH ₂ ) _0-3 -heteroaryl, -SO ₂ -(CH ₂ ) ₀ - ₃ -substituted heteroaryl, -CO-Ci-C ₆ alkyl, -CO-(CH ₂ )o- ₃ -aryl, -CO-(CH ₂ )o- ₃ -substituted aryl, -CO-(CH ₂ )o _-3 -heteroaryl, -CO-(CH ₂ ) _0-3 - substituted heteroaryl, -CO(CH ₂ )i. ₃ -CO ₂ -Ci-C ₆ -alkyl, -CO(CH ₂ )i. ₃ -CO ₂ -(CH ₂ ) ₀ - ₃ -aryl, -CONR ₅ (CH ₂ )i- ₃ -C0 ₂ -C,-C ₆ -alkyl, -CONR ₅ (CH ₂ )i. ₃ -C0 ₂ -(CH ₂ )o- ₃ -aryl, -CO(CH ₂ ) _I-3 -CO ₂ H, -CONR ₅ (CH ₂ ) _1-3 -CO ₂ H, -CON(R ₅ ) ₂ , -SO ₂ N(R ₅ ) ₂ , -CO ₂ -C ₁ -C ₆ alkyl, -C0 ₂ (CH ₂ )o _-3 -aryl, -C0 ₂ (CH ₂ )o- ₃ -substituted aryl, -CO ₂ (CH ₂ ) ₀ - ₃ -heteroaryl, or -CO ₂ (CH ₂ ) ₀ - ₃ -substituted heteroaryl;

R-5 at each occurrence is selected from H, CpCe alkyl, -(CH ₂ )o- ₃ -aryl, -(CH ₂ )o- ₃ - substituted aryl, -(CH ₂ )o- ₃ -heteroaryl, or -(CH ₂ )o- ₃ -substituted heteroaryl; and

Ar is aryl, substituted aryl, heteroaryl, or substituted heteroaryl.

[0011] In other embodiments, the invention relates to compositions comprising at least one compound of Formula 1, or a pharmaceutically acceptable salt thereof, and one or more pharmaceutically acceptable excipients, diluents, or carriers.

[0012] The present invention also provides methods for treating patients suffering from osteoporosis, arthritis, chronic obstructive pulmonary disease, cartilage defects, bone fractures, leiomyoma, acute myeloid leukemia, wound healing, prostate cancer, as well as autoimmune inflammatory disorders such as Graves ophthalmopathy, and combinations thereof, that comprise administering to the patients a therapeutically effective amount of at least one compound of Formula 1.

[0013] Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0014] The term "alkyl," as used herein, refers to an optionally substituted aliphatic hydrocarbon chain having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 6 ,1 to 4 or 1-3 carbon atoms. The term "alkyl" includes straight and branched chains. Straight chain alkyl groups have 1 to 8 carbon atoms and branched chain alkyl groups have 3 to 12 carbon atoms. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, isopentyl, neo-pentyl, n-hexyl, and isohexyl groups.

[0015] The term "perfluoroalkyl," as used herein, refers to an optionally substituted straight or branched aliphatic hydrocarbon chain of 1 to 8 carbon atoms and preferably 1 to 3 carbon atoms, in which all hydrogens are replaced with fluorine.

[0016] The term "alkoxy," as used herein, refers to the group -O-R' where R' is an alkyl group as previously defined; e.g., of 1-3 carbon atoms.

[0017] The term "perfluoroalkoxy," as used herein, refers to the group -O-R" where R" is a perfluoroalkyl group as previously defined.

[0018] The term "aryl," as used herein refers to an optionally substituted carbocyclic aromatic ring. Aryl groups may be monocyclic or bicyclic and may have 6-14 carbon atoms, e.g., 6-10 carbon atoms. Exemplary aryl groups include phenyl and naphthyl.

[0019] The term "heteroaryl," as used herein refers to an optionally substituted 5 to 10 membered monocyclic or bicyclic carbon containing aromatic ring having 1 to 3 of its ring members independently selected from nitrogen, sulfur and oxygen. Monocyclic rings preferably have 5 to 6 members and bicyclic rings preferably have 8 to 10 membered ring structures. Examples of heteroaryls include, but are not limited to, thienyl, furyl, pyrrolyl, imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolyl, indazolyl, benzofuranyl, isobenzofuranyl, benzothienyl, isobenzothienyl, quinolyl, isoquinolyl, quinoxalinyl, and quinazolinyl.

[0020] The terms "halogen" or "halo," as used herein, refer to chlorine, bromine, fluorine or iodine.

[0021] As used herein, the terms "optionally substituted" or "substituted or unsubstituted" are intended to refer to the optional replacement of up to four hydrogen atoms with up to four independently selected substituent groups as defined herein. Unless otherwise specifϊced, suitable substituent groups independently include hydroxyl, nitro, amino, imino, cyano, halo, thio, sulfonyl, aminocarbonyl, carbonylamino, carbonyl, oxo, guanidine, carboxyl, formyl, alkyl, perfluoroalkyl, alkyamino, dialkylamino, alkoxy, alkylcarbonyl, arylcarbonyl, aryl, heteroaryl, heterocycloalkyl, cycloalkyl, haloalkyl, perfluoroalkylalkyl, alkenyl, alkynyl, arylalkyl and the like. Substituent groups that have one or more available hydrogen atoms can in turn optionally bear further independently selected substituents, to a maximum of three levels of substitutions. For example, the term "optionally substituted aryl" is intended to mean an aryl group that can optionaly have up to four of its hydrogen atoms replaced with substituent groups as defined above (i.e., a first level of substitution), wherein each of the substituent groups attached to the aryl group can optionally have up to four of its hydrogen atoms replaced by substituent groups as defined above (i.e., a second level of substitution), and each of the substituent groups of the second level of substitution can optionally have up to four of its

hydrogen atoms replaced by substituent groups as defined above (i.e., a third level of substitution).

[0022] Unless indicated otherwise, the nomenclature of substituents that are not explicitly defined herein are arrived at by naming the terminal portion of the functionality followed by the adjacent functionality toward the point of attachment. For example, the substituent "arylalkoxycabonyl" refers to the group (aryl)-(alkyl)-O-C(O)-.

[0023] It is understood that the above definitions are not intended to include impermissible substitution patterns (e.g., methyl substituted with 5 fluoro groups). Such impermissible substitution patterns are well known to the skilled artisan.

[0024] The term "protecting group" with respect to amine groups, hydroxyl groups and sulfhydryl groups refers to forms of these functionalities which are protected from undesirable reaction with a protecting group known to those skilled in the art, such as those set forth in Protective Groups in Organic Synthesis, Greene, T. W.; Wuts, P. G. M., John Wiley & Sons, New York, NY, (3rd Edition, 1999) which can be added or removed using the procedures set forth therein. Examples of protected hydroxyl groups include, but are not limited to, silyl ethers such as those obtained by reaction of a hydroxyl group with a reagent such as, but not limited to, t-butyldimethyl-chlorosilane, trimethylchlorosilane, triisopropylchlorosilane, triethylchlorosilane; substituted methyl and ethyl ethers such as, but not limited to methoxymethyl ether, methythiomethyl ether, benzyloxymethyl ether, t-butoxymethyl ether, 2- methoxyethoxymethyl ether, tetrahydropyranyl ethers, 1 -ethoxyethyl ether, allyl ether, benzyl ether; esters such as, but not limited to, benzoylformate, formate, acetate, trichloroacetate, and trifluoracetate. Examples of protected amine groups include, but are not limited to, amides such as, formamide, acetamide, trifluoroacetamide, and benzamide; carbamates; e.g. BOC; imides, such as phthalimide, Fmoc, Cbz, PMB, benzyl, and dithiosuccinimide; and others. Examples of protected or capped sulfhydryl groups include, but are not limited to, thioethers such as S-benzyl thioether, and S-4-picolyl thioether; substituted S-methyl derivatives such as hemithio, dithio and aminothio acetals; and others.

[0025] Reference to "activated" or "an activating group" or "G _A " as used herein indicates having an electrophilic moiety bound to a substituent, capable of being displaced by a nucleophile. Examples of preferred activating groups are halogens, such as Cl, Br or I, and F; triflate; mesylate, or tosylate; esters; aldehydes; ketones; epoxides; and the like. An example of

an activated group is acetylchloride, which is readily attacked by a nucleophile, such as piperidine group to form a N-acetylpiperidine functionality.

[0026] The term "deprotecting" refers to removal of a protecting group, such as removal of a benzyl or BOC group bound to an amine. Deprotecting may be preformed by heating and/or addition of reagents capable of removing protecting groups. One preferred method of removing BOC groups from amino groups is to add HCl in ethyl acetate. Many deprotecting reactions are well known in the art and are described in Protective Groups in Organic Synthesis, Greene, T.W., John Wiley & Sons, New York, NY, (1st Edition, 1981).

[0027] The term "therapeutically effective amount," as used herein, refers to the amount of a compound of formula 1 that, when administered to a patient, is effective to at least partially treat a condition from which the patient is suffering or is suspected to suffer. Such conditions include, but are not limited to, osteoporosis, arthritis, chronic obstructive pulmonary disease, cartilage defects, bone fractures, and leiomyoma.

[0028] The term "pharmaceutically acceptable salts" or "pharmaceutically acceptable salt" includes acid addition salts, namely salts derived from treating a compound of formula 1 with an organic or inorganic acids or bases. Where the compound having formula I has an acidic function, for instance carboxy or phenolic hydroxyl, the term "pharmaceutically acceptable salts" or "pharmaceutically acceptable salt" includes salts derived from bases, for instance, sodium salts.

[0029] The term "patient," as used herein, refers to a mammal.

[0030] The terms "administer," "administering," or "administration," as used herein, refer to either directly administering a compound or composition to a patient, or administering a prodrug derivative or analog of the compound to the patient, which will form an equivalent amount of the active compound or substance within the patient's body.

[0031] The terms "treat" and "treating," as used herein, refer to partially or completely alleviating, inhibiting, preventing, ameliorating and/or relieving a condition from which a patient is suspected to suffer.

[0032] The terms "suffer" and "suffering," as used herein, refer to one or more conditions with which a patient has been diagnosed, or is suspected to have.

[0033] Certain embodiments of the invention relate to compounds of Formula (1):

or pharmaceutically acceptable salts thereof, wherein:

Ri is O, S, SO ₂ , or NR ₅ ;

R ₅ is H, Ci-C ₆ alkyl, -(CH ₂ )o- ₃ -aryl, -(CH ₂ )o- ₃ -substituted aryl, -(CH ₂ )o- ₃ -heteroaryl, or -(CH ₂ )o- ₃ -substituted heteroaryl;

R ₂ is C1-C3 alkylene;

R3 is Ci-C ₆ alkyl, C ₁ -C ₃ perfluoroalkyl, C ₁ -C ₃ perfluoroalkoxy, C ₁ -C ₃ alkoxy, halogen, or CN;

R4 is hydrogen, C)-C ₆ alkyl, -(CH ₂ )o- ₃ -aryl, -(CH ₂ )o-3 -substituted aryl, -(CH ₂ ) ₀ -3- heteroaryl, -(CH ₂ )o- ₃ -substituted heteroaryl, -SO ₂ -Ci-C ₆ alkyl, -SO ₂ -(CH ₂ ) _0-3 -aryl, -SO ₂ -(CH ₂ ) _O-3 - substituted aryl, -SO ₂ -(CH ₂ ) ₀ . ₃ -heteroaryl, -SO ₂ -(CH ₂ ) ₀ - ₃ -substituted heteroaryl, -CO-Ci-C ₆ alkyl, -CO-(CH ₂ ) ₀ - ₃ -aryl, -CO-(CH ₂ )o- ₃ -substituted aryl, -CO-(CH ₂ ) ₀ . ₃ -heteroaryl, -CO-(CH ₂ )o- ₃ - substituted heteroaryl, -CO(CH ₂ ) ₁ - ₃ -CO ₂ -C i-C ₆ -alkyl, -CO(CH ₂ )i _-3 -CO ₂ -(CH ₂ ) ₀ - ₃ -aryl, -CONR ₅ (CH ₂ )i-3-C0 ₂ -CrC ₆ -alkyl, -CONR ₅ (CH ₂ )i- ₃ -C0 ₂ -(CH ₂ )o- ₃ -aryl, -CO(CH ₂ ) _L3 -CO ₂ H, -CONR ₅ (CH ₂ ) _L3 -CO ₂ H, -CON(R ₅ ) ₂ , -SO ₂ N(R ₅ ) ₂ , -CO ₂ -C ₁ -C ₆ alkyl, -CO ₂ (CH ₂ ) _0-3 -aryl, -C0 ₂ (CH ₂ )o- ₃ -substituted aryl, -CO ₂ (CH ₂ )o-3 -heteroaryl, or -C0 ₂ (CH ₂ )o- ₃ -substituted heteroaryl; and

Ar is aryl, substituted aryl, heteroaryl, or substituted heteroaryl.

[0034] The aryl and heteroaryl groups found in compounds of Formula 1 are optionally substituted with one or more substituents that include, for example, halogen, CN, OH, NO ₂ , amino, -alkylamino, -dialkylamino, alkyl, cycloalkyl, aryl, heteroaryl, alkenyl, alkynyl, Ci to C ₃ alkoxy, Ci to C ₃ perfluoroalkyl, Ci to C ₃ perfluoroalkoxy, -0-(CH ₂ )o- ₃ -aryl, -S-(CH ₂ )o-3-aryl, alkylcarbonyl, including -CO-(Ci to C ₆ alkyl) and -CO-(Ci to C ₆ substituted alkyl), -CO-(CH ₂ )o- ₃ -aryl, -SO ₂ -(C, to C ₆ alkyl), -SO ₂ -(Ci to C ₆ substituted alkyl), -SO ₂ -(CH ₂ ) _0-3 -aryl, -COOH,

tetrazole, alkylcarboxy, including -COO-(Ci to C ₆ alkyl) and -COO-(Ci to C ₆ substituted alkyl), - COO-(CH ₂ )o- ₃ -aryl, and -CON(R ₅ ) ₂ .

[0035] In certain embodiments of the invention, Ar of Formula 1 is aryl or substituted aryl. In preferred embodiments, Ar is aryl, and in particularly preferred embodiments, Ar is phenyl.

[0036] Other aspects of the invention are directed to compounds of Formula 1 in which Ri is O, S, or SO ₂ . Preferably, Ri is S or SO ₂ . In more preferred embodiments of the invention, Ri is S.

[0037] Additional embodiments of the invention relate to compounds of Formula 1 in which R ₂ of Formula 1 is methylene or ethylene. R ₂ is preferably methylene.

[0038] Further embodiments of the invention are directed to compounds of Formula 1 in which R3 is Ci-C ₆ alkyl or C ₁ -C ₃ perfluoroalkyl. In preferred embodiments, R ₃ is C ₁ -C ₃ perfluoroalkyl, and in particularly preferred embodiments, R ₃ is perfluoromethyl.

[0039] Other aspects of the invention relate to compounds of Formula 1 in which R ₄ is hydrogen, -CO ₂ -Ci-C ₆ alkyl, -SO ₂ -(CH ₂ ) _0-3 -substituted aryl, -SO ₂ N(R ₅ ) ₂ , -CO(CH ₂ )L ₃ -CO ₂ -Ci- C ₆ -alkyl, -CO(CH ₂ )i _-3 -CO ₂ H, -CO-(CH ₂ ) ₀ - ₃ -substituted aryl, -CO-(CH ₂ )o- ₃ -substituted heteroaryl, -CON(Rs) ₂ , -CONR ₅ (CH ₂ ) _I-3 -CO ₂ H, or -CONR ₅ (CH ₂ )i.3-CO ₂ -Ci-C ₆ -alkyl.

[0040] Still further embodiments of the invention relate to compounds of Formula 1 in which R ₄ is hydrogen, -CO ₂ tertbutyl, -SO ₂ -substituted phenyl, -SO ₂ N(CH ₃ ) ₂ , -CO(CH ₂ ) ₂ - CO ₂ CH ₃ , -CO(CH ₂ ) ₂ CO ₂ H, CO-substituted phenyl, CO-substituted pyridyl, -CON(H)C(CH ₃ ) ₃ , -CON(CH ₃ ) ₂ , -CONHCH ₂ CO ₂ H, or -CONHCH ₂ -CO ₂ -CH ₂ -CH ₃ .

[0041] In preferred embodiments, R ₄ is -SO ₂ -substituted phenyl, CO-substituted phenyl, -CO(CH ₂ ) ₂ CO ₂ H, or -CONHCH ₂ CO ₂ H. And in particularly preferred embodiments of the invention, R ₄ is -SO ₂ -substiruted phenyl.

[0042] Additional embodiments of the invention relate to compounds of Formula 1 in which Ar is phenyl; Ri is S or SO ₂ ; R ₂ is methylene; R ₃ is perfluoromethyl; and R ₄ is hydrogen, - CO ₂ -Ci-C ₆ alkyl, -SO ₂ -(CH ₂ ) ₀ -3-substituted aryl, -SO ₂ N(R ₅ ) ₂ , -CO(CH ₂ )i. ₃ -CO ₂ -Ci-C ₆ -alkyl, - CO(CH ₂ ) _I-3 -CO ₂ H, -CO-(CH ₂ )o _-3 -substituted aryl, -CO-(CH ₂ ) ₀ - ₃ -substituted heteroaryl, - CON(Rs) ₂ , -CONRs(CH ₂ ) _I-3 -CO ₂ H, or -CONR ₅ (CH ₂ )i _-3 -CO ₂ -Ci-C ₆ -alkyl.

[0043] Specific, representative compounds of Formula 1 include: tert-butyl 4-({[5-(phenylsulfonyl)-2-(rrifluoromethyl)phenyl]thio}methy l)piperidine-l- carboxylate;

4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}me thyl)piperidine hydrochloride; 3-{[4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}m ethyl)ρiperidin-l- yl]sulfonyl} benzoic acid;

3- {[4-( {[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]sulfonyl}meth yl)piperidin-l - yljsulfonyl} benzoic acid; methyl 4-oxo-4-[4-( {[5-(phenylsulfonyl)-2- (trifluoromethyl)phenyl]thio}methyl)piperidin-l-yl]butanoate ; ethyl N- { [4-( { [5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio} methyl)piperidin- 1 - yl]carbonyl}glycinate; methyl 4-{[4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}m ethyl)piperidin-l- yl] carbony 1 } benzoate ;

2-chloro-5-{[4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)p henyl]thio}methyl)piperidin-l- yl]carbonyl } pyridine;

5-{[4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thi o}methyl)piperidin-l- yl]carbonyl}-2-(trifluoromethyl)pyridine;

N-tert-butyl-4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)p henyl]thio}methyl)ρiperidine-l- carboxamide;

N,N-dimethyl-4-( { [ 5 -(phenylsulfonyl)-2-(trifluoromethyl)phenyl] thio } methyl)piperidine- 1 -sulfonamide;

N,N-dimethyl-4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)p henyl]thio}methyl)piperidine- 1-carboxamide;

4-{[4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thi o}methyl)piperidin-l- yl]sulfonyl}benzoic acid;

3 - { [4 -( { [5 -(phenylsulfonyl)-2-(trifluoromethyl)phenyl] thio } methyl)piperidin- 1 - yl] sulfonyl } benzonitrile;

N-{[4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thi o}methyl)piperidin-l- yl]carbonyl}glycine;

4- {[4-( {[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}methyl)p iperidin-l - yl]carbonyl}benzoic acid; and

4-oxo-4-[4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)pheny l]thio}methyl)piperidin-l- yl]butanoic acid.

[0044] Particularly preferred compounds of Formula 1 include:

3-{[4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thi o}methyl)piperidin-l- yl]sulfonyl}benzoic acid;

4-{[4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thi o}methyl)piperidin-l- yl]sulfonyl}benzoic acid;

N-{[4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thi o}methyl)piperidin-l- yl]carbonyl}glycine;

4- {[4-( {[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}methyl)p iperidin-l - yl]carbonyl}benzoic acid; and

4-oxo-4-[4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)pheny l]thio}methyl)piperidin-l- yl]butanoic acid.

[0045] Compounds of Formula 1 may be used to modulate the activity of secreted frizzled related protein- 1. Such compounds are of interest for the treatment of osteoporosis, arthritis, chronic obstructive pulmonary disease, cartilage defects, bone fractures, leiomyoma, acute myeloid leukemia, wound healing, prostate cancer, as well as autoimmune inflammatory disorders such as Graves ophthalmopathy, and combinations thereof.

[0046] In certain embodiments, the present invention therefore provides methods of treating, preventing, inhibiting, or alleviating each of the maladies listed above in a mammal, preferably in a human, comprising administering a therapeutically effective amount of a compound of Formula 1 or a pharmaceutically acceptable salt thereof to a patient suspected to suffer from such a malady.

[0047] In other embodiments, the invention relates to compositions comprising at least one compound of Formula 1, or a steroisomer or pharmaceutically acceptable salt thereof, and one or more pharmaceutically acceptable carriers, excipients, or diluents. Such compositions include pharmaceutical compositions for treating or controlling disease states or conditions of the bone. In certain embodiments, the compositions comprise mixtures of one or more compounds of Formula 1.

[0048] Certain of the compounds of Formula 1 contain stereogenic carbon atoms or other chiral elements and thus give rise to stereoisomers, including enantiomers and diastereomers. The invention generally relates to all stereoisomers of the compounds of Formula 1, as well as to mixtures of the stereoisomers. Throughout this application, the name of a compound without indication as to the absolute configuration of an asymmetric center is intended to embrace the individual stereoisomers as well as mixtures of stereoisomers. Reference

to optical rotation [(+), (-) and (±)] is utilized to distinguish the enantiomers from one another and from the racemate. Furthermore, throughout this application, the designations R* and S* are used to indicate relative stereochemistry, employing the Chemical Abstracts convention which automatically assigns R* to the lowest numbered asymmetric center.

[0049] An enantiomer can, in some embodiments of the invention, be provided substantially free of the corresponding enantiomer. Thus, reference to an enantiomer as being substantially free of the corresponding enantiomer indicates that it is isolated or separated via separation techniques or prepared so as to be substantially free of the corresponding enantiomer. "Substantially free," as used herein, means that a significantly lesser proportion of the corresponding enantiomer is present. In preferred embodiments, less than about 90 % by weight of the corresponding enantiomer is present relative to desired enantiomer, more preferably less than about 1% by weight. Preferred enantiomers can be isolated from racemic mixtures by any method known to those skilled in the art, including high performance liquid chromatography (HPLC), and the formation and crystallization of chiral salts, or preferred enantiomers, can be prepared by methods described herein. Methods for the preparation of enantiomers are described, for example, in Jacques, et ah, Enantiomers, Racemates and Resolutions (Wiley Interscience, New York, 1981); Wilen, S.H., et al., Tetrahedron 33:2725 (1977); EHeI, E.L. Stereochemistry of Carbon Compounds (McGraw-Hill, NY, 1962); and Wilen, S.H. Tables of Resolving Agents and Optical Resolutions p. 268 (E.L. Eliel, Ed., Univ. of Notre Dame Press, Notre Dame, IN 1972), each of which is hereby incorporated by reference in its entirety.

[0050] The following synthetic schemes are designed to illustrate, but not limit, general procedures for the preparation of compounds of Formula 1. The reagents used can be either commercially obtained or can be prepared by standard procedures described in the literature.

Scheme 1 Exemplified for R, = S or SO ₂ and R ₃ = CF ₃

5

[0051] As described in Scheme 1, the appropriately substituted sulfonyl chloride 1 can be reacted with an aromatic compound such as benzene, in the presence of a Lewis acid catalyst such as aluminum chloride, with or without heating, to yield the desired aryl sulfone 2. Reaction of 2 with dibromodifluoromethane in a suitable solvent such as N,N-dimethylacetamide in the presence of copper and activated carbon, at an elevated temperature such as 100 ⁰ C, yields the trifluoromethyl aryl sulfone 3. Treatment of 3 with sodium sulfide in a solvent such as N,N- dimethylformamide, followed by the addition of a suitably protected halogen or other reactive piperidine derivative such as 4, yields the sulfide 5. Deprotection of 5 in the presence of an acid and appropriate solvent, such as anhydrous HCl in ethyl acetate, yields the amine 6. Reaction of

6 with a variety of electrophiles, for example, acid chlorides, sulfonyl chloride or isocyanates, yields the desired substituted piperidine derivatives 7. Oxidation of 7 with an oxidant such as 30% hydrogen peroxide, in a solvent such as glacial acetic acid, at elevated temperatures yields the sulfones 8.

[0052] In certain embodiments, the invention relates to compositions comprising at least one compound of Formula 1, or a stereoisomer or pharmaceutically acceptable salt thereof, and one or more pharmaceutically acceptable carriers, excipients, or diluents. Such compositions are prepared in accordance with general pharmaceutical formulation procedures, such as, for example, those described in Remingtons Pharmaceutical Sciences, 17th edition, ed. Alfonoso R. Gennaro, Mack Publishing Company, Easton, PA (1985), which is incorporated herein by reference in its entirety. Pharmaceutically acceptable carriers are those carriers that are compatible with the other ingredients in the formulation and are biologically acceptable.

[0053] The compounds of Formula 1 can be administered orally or parenterally, neat, or in combination with conventional pharmaceutical carriers. Applicable solid carriers can include one or more substances that can also act as flavoring agents, lubricants, solubilizers, suspending agents, fillers, glidants, compression aids, binders, tablet-disintegrating agents, or encapsulating materials. In powders, the carrier is a finely divided solid that is in admixture with the finely divided active ingredient. In tablets, the active ingredient is mixed with a carrier having the necessary compression properties in suitable proportions and compacted in the shape and size desired. The powders and tablets preferably contain up to 99 % of the active ingredient. Suitable solid carriers include, for example, calcium phosphate, magnesium stearate, talc, sugars, lactose, dextrin, starch, gelatin, cellulose, methyl cellulose, sodium carboxymethyl cellulose, polyvinylpyrrolidine, low melting waxes and ion exchange resins.

[0054] Liquid carriers can be used in preparing solutions, suspensions, emulsions, syrups and elixirs. The active ingredient can be dissolved or suspended in a pharmaceutically acceptable liquid carrier such as water, an organic solvent, a mixture of both, or a pharmaceutically acceptable oil or fat. The liquid carrier can contain other suitable pharmaceutical additives such as, for example, solubilizers, emulsifϊers, buffers, preservatives, sweeteners, flavoring agents, suspending agents, thickening agents, colors, viscosity regulators, stabilizers or osmo-regulators. Suitable examples of liquid carriers for oral and parenteral administration include water (particularly containing additives as above, e.g. cellulose derivatives, preferably sodium carboxymethyl cellulose solution), alcohols (including

monohydric alcohols and polyhydric alcohols e.g. glycols) and their derivatives, and oils (e.g. fractionated coconut oil and arachis oil). For parenteral administration, the carrier can also be an oily ester such as ethyl oleate and isopropyl myristate. Sterile liquid carriers are used in sterile liquid form compositions for parenteral administration. The liquid carrier for pressurized compositions can be halogenated hydrocarbon or other pharmaceutically acceptable propellant.

[0055] Liquid pharmaceutical compositions that are sterile solutions or suspensions can be administered by, for example, intramuscular, intraperitoneal or subcutaneous injection. Sterile solutions can also be administered intravenously. Compositions for oral administration can be in either liquid or solid form.

[0056] The compounds of Formula 1 can be administered rectally or vaginally in the form of a conventional suppository. For administration by intranasal or intrabronchial inhalation or insufflation, the compounds of Formula 1 can be formulated into an aqueous or partially aqueous solution, which can then be utilized in the form of an aerosol. The compounds of Formula 1 can also be administered transdermally through the use of a transdermal patch containing the active compound and a carrier that is inert to the active compound, is non-toxic to the skin, and allows delivery of the agent for systemic absorption into the blood stream via the skin. The carrier can take any number of forms such as creams and ointments, pastes, gels, and occlusive devices. The creams and ointments can be viscous liquid or semisolid emulsions of either the oil-in-water or water-in-oil type. Pastes comprised of absorptive powders dispersed in petroleum or hydrophilic petroleum containing the active ingredient can also be suitable. A variety of occlusive devices can be used to release the active ingredient into the blood stream such as a semipermeable membrane covering a reservoir containing the active ingredient with or without a carrier, or a matrix containing the active ingredient. Other occlusive devices are known in the literature.

[0057] Preferably the pharmaceutical composition is in unit dosage form, e.g. as tablets, capsules, powders, solutions, suspensions, emulsions, granules, or suppositories. In such form, the composition is sub-divided in unit dose containing appropriate quantities of the active ingredient; the unit dosage forms can be packaged compositions, for example, packeted powders, vials, ampoules, prefilled syringes or sachets containing liquids. The unit dosage form can be, for example, a capsule or tablet itself, or it can be the appropriate number of any such compositions in package form.

[0058] The amount provided to a patient will vary depending upon what is being administered, the purpose of the administration, such as prophylaxis or therapy, and the state of the patient, the manner of administration, and the like. In therapeutic applications, compounds of Formula 1 are provided to a patient already suffering from a disease in an amount sufficient to cure or at least partially ameliorate the symptoms of the disease and its complications. An amount adequate to accomplish this is defined as a "therapeutically effective amount." The dosage to be used in the treatment of a specific case must be subjectively determined by the attending physician. The variables involved include the specific condition and the size, age, and response pattern of the patient. The compounds can be administered orally, rectally, parenterally, or topically to the skin and mucosa. The usual daily dose depends on the specific compound, method of treatment and condition treated. The usual daily dose is 0.01 - 1000 mg/kg for oral application, preferably 0.5 - 500 mg/kg, and 0.1 - 100 mg/kg for parenteral application, preferably 0.5 - 50 mg/kg.

[0059] In certain embodiments, the present invention is directed to prodrugs of compounds of Formula 1. The term "prodrug," as used herein, means a compound that is convertible in vivo by metabolic means (e.g. by hydrolysis) to a compound of Formula 1. Various forms of prodrugs are known in the art such as those discussed in, for example, 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 Delivery Reviews, 8:1-38(1992), Bundgaard, J. of Pharmaceutical Sciences, 77:285 et seq. (1988); and Higuchi and Stella (eds.) Prodrugs as Novel Drug Delivery Systems, American Chemical Society (1975), each of which is hereby incorporated by reference in its entirety.

[0060] The following examples are illustrative of certain embodiments of the invention and should not be considered to limit the scope of the invention. ACD NamePro software was employed to generate IUPAC names for the following examples. The IUPAC names of the following examples are indicative of the neutral or free base forms. Compounds were either isolated as a free base or the corresponding hydrochloride salt as indicated in the experimental procedure.

Example 1: tert-Butyl 4-({[5-(phenylsulfonyl)-2- (trifluoromethyl)phenyl)thio}methyl)piperidine-l-carboxylate

[0061] Step l : l-Chloro-2-nitro-4-(phenylsulfonyl)benzene

Aluminum chloride (15.64 g, 117.3 mmol) was added to a solution of 4-chloro-3-nitro- benzenesulfonyl chloride (25.02 g, 97.7 mmol) in 75 mL of benzene and the reaction stirred under nitrogen at room temperature for 16 h and then refluxed for 2 h. After cooling to room temperature 2 N HCl (75 mL) was added dropwise. The mixture was partitioned between 2 N HCl and ethyl acetate. The emulsion that formed was separated by the addition of saturated NaCl. The organic layer was separated, extracted one time with water, one time with saturated NaCl, dried (anhydrous MgSO ₄ ), filtered and the solvent removed under reduced pressure to give l-chloro-2-nitro-4-(phenylsulfonyl)benzene (27.84 g, 96%) as a brown solid, MS (EI) m/z 296.9;

HRMS: calcd for Ci ₂ H ₈ ClNO ₄ S, 296.98626; found (EI, M ⁺ .), 296.9849.

[0062] Step 2: 2-Nitro-4-(phenylsulfonyl)-l-(trifluoromethyl)benzene

Copper (8.8909 g, 140 mmol) was added under nitrogen to a solution of l-chloro-2- nitro-4-(phenylsulfonyl)benzene (6.9385 g, 23.3 mmol), prepared in the previous step, in 40 mL of anhydrous N,N-dimethylacetamide at room temperature. Activated carbon (100 mesh), previously dried at 200 ⁰ C for 45 minutes, was then added. Dibromo-difluoro-methane (4.26 mL, 46.6 mmol) was added in two portions and the resulting mixture stirred at room temperature for 1 h, at 100 ⁰ C for 3 h and then stood at room temperature overnight. The mixture was filtered through celite. The filtrate was partitioned between 10% ammonium chloride and ethyl acetate. The emulsion that formed was separated by the addition of saturated NaCl. The organic layer was separated, extracted 5 times with water, dried (anhydrous MgSO ₄ ), filtered and the solvent removed under reduced pressure to give 6.61 g of a brown oil. Purification of the oil on 1 Kg of silica gel (230-400 mesh) using 50 % methylene chloride-hexane as the eluent gave 2-nitro-4- (phenylsulfonyl)-l-(trifluoromethyl)benzene (4.25 g, 55%) as a white solid, MS (EI) m/z 331; HRMS: calcd for Ci ₃ H ₈ F ₃ NO ₄ S, 331.01261; found (EI, M ⁺ .), 331.0128.

[0063] Step 3: tert-Butyl 4-({[5-(phenylsulfonyl)-2- (trifluoromethyl)phenyl]thio}methyl)piperidine- 1 -carboxylate

Sodium sulfide (59.0 mg, 0.727 mmol) was added to a solution of 2-nitro-4- (phenylsulfonyl)-l-(trifluoromethyl)benzene (217.9 mg, 0.658 mmol), prepared in the previous step, in 3.5 mL of N,N-dimethylformamide at room temperature and the reaction stirred at room temperature for 2 h. 4-Bromomethyl-piperidine-l-carboxylic acid tert-butyl ester (202.3 mg, 0.727 mmol) in 1.4 mL of N,N-dimethylformamide was added and the reaction stirred at room temperature for 2 h. The reaction was partitioned between ethyl acetate and water. The organic layer was separated, extracted 3 times with water and the solvent removed under reduced pressure. The residue was purified on a 12 g KediSep ^R silica gel column using a gradient of 100% hexane to 67% hexane-ethyl acetate as the eluent gave 204.4 mg of an oil. Additional purification of this oil on a 12 g RediSep ^R silica gel column using a gradient of 90% hexane- methylene chloride to 100% methylene chloride gave the title compound (150.3 mg, 44%) as a clear oil, MS (ES) m/z 516.0;

Anal. Calcd for C ₂₄ H ₂₈ F ₃ NO ₄ S ₂ : C, 55.91; H, 5.47; N, 2.72. Found: C, 59.11; H, 5.38; N, 2.56.

Example 2: 4-({[5-(Phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}methy l)piperidine hydrochloride

[0064] A solution of ethyl acetate, saturated with anhydrous HCl gas, (0.5 mL) was added to a solution of tert-butyl 4-({[5-(phenylsulfonyl)-2-

(trifluoromethyl)phenyl]thio}methyl)piperidine-l -carboxylate (185.4 mg, 0.360 mmol), prepared in step 3 of Example 1, in 0.5 mL of ethyl acetate at room temperature. After 2 h at room temperature a solid was present. The solvent was decanted. Additional ethyl acetate was added and the mixture stirred at room temperature. The ethyl acetate was again decanted and the solid dried at 100 ⁰ C under reduced pressure to give the title compound (145.4 mg, 89%) as a white solid, MS (ES) m/z 416.0;

HRMS: calcd for Ci ₉ H ₂₀ F ₃ NO ₂ S ₂ + H ⁺ , 416.09603; found (ESI, [M+H] ⁺ ), 416.0974;

Anal. Calcd for Ci ₉ H ₂₀ F ₃ NO ₂ S ₂ . HCl: C, 50.49; H, 4.68; N, 3.10. Found: C, 50.29; H, 4.71; N, 3.04.

Example 3: 3-{[4-({[5-(Phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}m ethyl)piperidin-l- yl]sulfonyl} benzoic acid

[0065] N,N-Diisopropylethylamine (190 μL, 1.09 mmol) was added under nitrogen to a mixture of 4-({[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}methy l)piρeridine hydrochloride (199.8 mg, 0.442 mmol), prepared in Example 2, and 3-chlorosulfonyl-benzoic acid (104.9 mg, 0.476 mmol) in 11 mL of methylene chloride at room temperature. After the addition the reaction was stirred at room temperature for 3 h. The reaction was extracted 2 times with 2 N HCl, 1 time with water and then concentrated under reduced pressure to a volume of approximately 5 mL. A solid was present. Methanol and ethyl acetate were added to dissolve the solid (total volume approximately 12 mL). Silica gel was added to this solution and the solvent allowed to evaporate at 4O ⁰ C. The solid, absorbed on the silica gel, was purified on a 12 g RediSep ^K silica gel column. Using a gradient of 65% hexane-ethyl acetate to 100% ethyl acetate the title compound was isolated (96.2 mg, 36%) as a white solid, MS (ES) m/z 599.8;

Anal. Calcd for C ₂₆ H ₂₄ F ₃ NO ₆ S ₃ : C, 52.08; H, 4.03; N, 2.34. Found: C, 52.10; H, 3.89; N, 2.34.

Example 4: 3-{[4-({[5-(Phenylsulfonyl)-2- (trifluoromethyl)phenyl]sulfonyl}methyl)piperidin-l-yl]sulfo nyl}benzoic acid

[0066] A suspension of 3-{[4-({[5-(phenylsulfonyl)-2-

(trifluoromethyl)phenyl]thio}methyl)piperidin-l-yl]sulfonyl} benzoic acid (116.1 mg, 0.194 mmol), prepared in Example 3, in 4.3 mL of glacial acetic acid was warmed to approximately 5O ⁰ C to dissolve the solid. To this solution 30% hydrogen peroxide (330 μL, 3 mmol) was added and the reaction was stirred at 9O ⁰ C for 4 h. The acetic acid was removed under reduced pressure and the residue partitioned between methylene chloride and water. The organic layer was separated, diluted with ethyl acetate, extracted 1 time with water, 1 time with saturated NaCl, dried (anhydrous MgSO ₄ ), filtered and the solvent removed under reduced pressure to give 1 14.1 mg of a tan solid. The solid was triturated with 1 :1 hexane: ethyl acetate and then dried under reduced pressure at 100 ⁰ C over night to give the title compound (63.9 mg, 52%) as a white solid, MS (ES) m/z 632.1 ;

Anal. Calcd for C ₂₆ H ₂₄ F ₃ NO ₈ S ₃ : C, 49.44; H, 3.83; N, 2.22. Found: C, 49.60; H, 3.68; N, 2.15.

Example 5: Methyl 4-oxo-4-[4-({[5-(phenylsulfonyI)-2- (trifluoromethyl)phenyl]thio}methyl)piperidin-l-yl]butanoate

[0067] N,N-Diisopropylethylamine (180 μL, 1.03 mmol) was added to a mixture of 4- ({[5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}methyl) piperidine hydrochloride (150.0 mg, 0.332 mmol), prepared in Example 2, and 3 -chlorocarbonyl -propionic acid methyl ester (50.5 mg, 0.336 mmol) in 8 mL of methylene chloride at room temperature. After the addition the reaction was stirred at room temperature. The reaction was monitored by thin-layer chromatography (TLC). At the end of the reaction time the mixture was extracted with 2 N HCl, water, saturated NaCl and then purified on a 4 g Redi&p ^R silica gel column. Using a gradient of 100% hexane to 40% hexane-ethyl acetate the title compound was isolated (137.9 mg, 78%) as a white solid, MS (ES) m/z 530.2;

HRMS: calcd for C ₂₄ H ₂₆ F ₃ NO ₅ S ₂ + H ⁺ , 530.12772; found (ESI, [M+H] ⁺ ), 530.1274.

Example 6: Ethyl N-{[4-({[5-(phenylsulfonyl)-2- (trifluoromethyl)phenyl]thio}methyl)piperidin-l-yl]carbonyl} glycinate

[0068] In the same manner as described in Example 5, and replacing 3-chlorocarbonyl- propionic acid methyl ester with isocyanato-acetic acid ethyl ester, the title compound was isolated (175.2 mg, 47%) as an colorless amorphous solid, MS (ES) m/z 545.2;

HRMS: calcd for C ₂₄ H ₂₇ F ₃ N ₂ O ₅ S ₂ + H ⁺ , 545.13862; found (ESI, [M+H] ⁺ ), 545.1365.

Example 7: Methyl 4-{[4-({[5-(phenylsuIfonyI)-2- (trifluoromethyl)phenyl]thio}methyl)piperidin-l-yl]carbonyl} benzoate

[0069] In the same manner as described in Example 5, and replacing 3-chlorocarbonyl- propionic acid methyl ester with 4-chlorocarbonyl-benzoic acid methyl ester, the title compound was isolated (160.5 mg, 83%) as a white solid, MS (ESI) m/z 578;

HRMS: calcd for C ₂₈ H ₂₆ F ₃ NO ₅ S ₂ + H ⁺ , 578.12772; found (ESI, [M+H] ⁺ ), 578.1288.

Example 8: 2-Chloro-5-{[4-({[5-(phenylsulfonyl)-2- (trifluoromethyl)phenyl]thio}methyl)piperidin-l-yl]carbonyl} pyridine

[0070] In the same manner as described in Example 5, replacing 3-chlorocarbonyl- propionic acid methyl ester with 6-chloro-nicotinoyl chloride and extracting with 37 μL of 1 N

HCl instead of 2 N HCl, the title compound was isolated (164.6 mg, 90%) as a white solid, MS (ES) m/z 555.1;

HRMS: calcd for C ₂₅ H ₂₂ ClF ₃ N ₂ O ₃ S ₂ + H ⁺ , 555.07852; found (ESI, [M+H] ⁺ ), 555.0784.

Example 9: 5-{[4-({[5-(PhenylsulfonyI)-2-(trifluoromethyl)phenyl]thio}m ethyl)piperidin-l- yl]carbonyl}-2-(trifluoromethyl)pyridine

[0071] In the same manner as described in Example 5, replacing 3-chlorocarbonyl- propionic acid methyl ester with 6-trifluoromethyl-nicotinoyl chloride and extracting with 36 μL of 1 N HCl instead of 2 N HCl, the title compound was isolated (171.2 mg, 88%) as a white solid, MS (ES) m/z 589.2;

HRMS: calcd for C ₂₆ H ₂₂ F ₆ N ₂ O ₃ S ₂ + H ⁺ , 589.10488; found (ESI, [M+H] ⁺ ), 589.1063.

Example 10: N-tert-Butyl-4-({[5-(phenylsulfonyl)-2- (trifluoromethyl)phenyl]thio}methyl)piperidine-l-carboxamide

[0072] In the same manner as described in Example 5, and replacing 3-chlorocarbonyl- propionic acid methyl ester with 2-isocyanto-2 -methyl-propane, the title compound was isolated (148.0 mg, 87%) as an amorphous white solid, MS (ES) m/z 515.2;

HRMS: calcd for C ₂₄ H ₂₉ F ₃ N ₂ O ₃ S ₂ + H ₊ , 515.16444; found (ESI, [M+H] ⁺ ), 515.166.

Example 11: N,N-Dimethyl-4-({[5-(phenylsuIfonyl)-2- (trifluoromethyl)phenyl]tbio}methyl)piperidine-l-sulfonamide

[0073] In the same manner as described in Example 5, and replacing 3-chlorocarbonyl- propionic acid methyl ester with dimethylsulfamoyl chloride, the title compound was isolated (159.5 mg, 92%) as a white solid, MS (ES) m/z 523.1;

HRMS: calcd for C _2I H ₂₅ F ₃ N ₂ O ₄ S ₃ + H ⁺ , 523.10013; found (ESI, [M+H] ⁺ ), 523.1109.

Example 12: N,N-DimethyI-4-({[5-(phenylsulfonyl)-2- (trifluoromethyl)phenyl]thio}methyl)piperidine-l-carboxamide

[0074] In the same manner as described in Example 5, and replacing 3-chlorocarbonyl- propionic acid methyl ester with dimethylcarbamoyl chloride, the title compound was isolated (153.7 mg, 95%) as a white solid, MS (ES) m/z 487.2;

HRMS: calcd for C ₂₂ H ₂₅ F ₃ N ₂ O ₃ S ₂ + H ⁺ , 487.13314; found (ESI, [M+H] ⁺ ), 487.1334.

Example 13: 4-{[4-({[5-(Phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}m ethyl)piperidin- l-yl]sulfonyl}benzoic acid

[0075] In the same manner as described in Example 5, and replacing 3-chlorocarbonyl- propionic acid methyl ester with 4-chlorosulfonyl-benzoic acid, the title compound was isolated (75.6 mg, 40%) as a white solid, MS (ES) m/z 600.1;

HRMS: calcd for C ₂₆ H ₂₄ F ₃ NO ₆ S ₃ + H ⁺ , 600.07906; found (ESI, [M+H] ⁺ ), 600.078.

Example 14: 3-{[4-({[5-(PhenylsuIfonyl)-2-(trifluoromethyl)phenyl]thio}m ethyl)piperidin- l-yl]sulfonyl}benzonitrile

[0076] In the same manner as described in Example 5, and replacing 3-chlorocarbonyl- propionic acid methyl ester with 3-cyano-benzenesulfonyl chloride, the title compound was isolated (188.6 mg, 98%) as a white amorphous solid, MS (ES) m/z 581.2;

HRMS: calcd for C ₂₆ H ₂₃ F ₃ N ₂ O ₄ S ₃ + H ⁺ , 581.08448; found (ESI, [M+H] ⁺ ), 581.0829.

Example 15: N-{[4-({[5-(Phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}m ethyl)piperidin-

1 -yl] carbonyl} glycine

[0077] Lithium hydroxide (400 μL of a 5.06 M solution; 2.02 mmol) was added to a solution of ethyl N- {[4-( { [5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio} methyl)piperidin- l-yl]carbonyl}glycinate (122.8 mg, 0.225 mmol), prepared in Example 6, in 3.3 mL of ethanol. After the addition the reaction was stirred at room temperature for 2 h. The reaction was concentrated under reduced pressure to remove the ethanol. The residue was partitioned between

2 N HCl and EtOAc. The solid present that was collected by filtration, rinsed with ethyl acetate, water and dried under reduced pressure at 8O ⁰ C to give the title compound (80.5 mg, 69%) as a white solid, MS (ES) m/z 517.0;

HRMS: calcd for C ₂₂ H ₂₃ F ₃ N ₂ O ₅ S ₂ + H ⁺ , 517.10732; found (ESI, [M+H] ⁺ ), 517.1077.

Example 16: 4-{[4-({[5-(Phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}m ethyl)piperidin- l-yl]carbonyl}benzoic acid

[0078] Lithium hydroxide (340 μL of a 5.06 M solution; 1.72 mmol) was added to a solution of methyl 4- { [4-( { [5-(phenylsulfonyl)-2-(trifluoromethyl)phenyl]thio}methyl)pi peridin- l-yl]carbonyl}benzoate (109.3 mg, 0.189 mmol), prepared in Example 7, in 2.7 mL of ethanol. After the addition the reaction was stirred at room temperature for 2 h and then at 4O ⁰ C until the

starting material was consumed as determined by thin-layer chromatography (TLC). The residue was partitioned between 2 N HCl and EtOAc. A solid was present. Most of the ethyl acetate was removed under reduced pressure and the solid present was collected by filtration, rinsed with ethyl acetate, water and dried under reduced pressure at 8O ⁰ C to give the title compound (69.0 mg, 65%) as a white solid, MS (ES) m/z 564.0;

HRMS: calcd for C ₂₇ H ₂₄ F ₃ NO ₅ S ₂ + H ⁺ , 564.11207; found (ESI, [M+H] ⁺ ), 564.1116.

Example 17: 4-Oxo-4-[4-({[5-(phenyIsulfonyl)-2- (trifluoromethyl)phenyl]thio}methyl)piperidin-l-yl]butanoic acid

[0079] Sodium hydroxide (59.6 mg, 1.49 mmol) in 2.5 mL of water was added to a solution of methyl 4-oxo-4-[4-({[5-(phenylsulfonyl)-2-

(trifluoromethyl)phenyl]thio}methyl)piperidin-l-yl]butanoate (307.5 mg, 0.581 mmol), prepared in Example 5, in 5 mL of tetrahydrofuran plus 5 mL of methanol. After the addition the reaction was stirred at 55 ⁰ C for 5 h. By LC/MS starting material remained. An additional amount of sodium hydroxide (94.4 mg of a 50% weight solution; 1.18 mmol) was added and the reaction stirred at 55 ⁰ C until the starting material was consumed as determined by LC/MS. The reaction was concentrated under reduced pressure, the residue partitioned between 2 N HCl and ethyl acetate and the mixture stirred at room temperature. The solid present was collected by filtration, washed with ethyl acetate, water and dried under reduced pressure at 9O ⁰ C to give the title compound (210.9 mg, 70%) as a white solid, MS (ES) m/z 516.0;

HRMS: calcd for C ₂₃ H ₂₄ F ₃ NO ₅ S ₂ + H ⁺ , 516.11207; found (ESI-FTMS, [M+H]l+), 516.11387.

Example 18: Fluorescence Polarization Binding Assay

[0080] The affinity of test compounds for SFRP-I was determined using a fluorescence polarization binding assay. According to the assay design, a probe compound was bound to SFRP- 1. The fluorescence anisotropy value of the probe compound is increased upon binding to SFRP-I. Upon the addition of a test compound, the fluorescence anisotropy value for the probe compound decreased due to competitive displacement of the probe by the test compound. The decrease in anisotropy as a function of increasing concentration of the test compound provides a direct measure of the test compound's binding affinity for SFRP-I .

[0081] To determine IC50 values, fluorescence polarization experiments were conducted in a 384-well format according to the following procedures. A 20 mM stock solution of the probe compound was prepared in 100 % DMSO and dispensed in 10 μL aliquots for long- term storage at -20 ⁰ C. The binding assay buffer was prepared by combining stock solutions of Tris-Cl, NacL, glycerol, and NP40 at final concentrations of 25 mM Tris-Cl pH 7.4, 0.5 M NaCl, 5% glycerol and 0.002 % NP40. Master stock solutions of the test compounds were prepared in 100 % DMSO at final concentrations of 20 mM. Typically the working stock solutions of the test compounds were prepared by serially diluting the 20 mM master stock solution to 5 mM, 2.5 mM, 1.25 mM, 0.625 mM, 0.3125 mM, 0.156 mM, 78 μM, 39 μM, 19.5 μM, 9.8 μM, 4.9 μM, 2.44 μM, 1.22 μM, 0.31 μM, 76 nM, and 19 nM in DMSO. The working stock solutions of the test compounds were further diluted by combining 6 μl of the solutions with 24 μL of Milli-Q purity water, resulting in working stock solutions (10x compound stocks) in 20 % DMSO.

[0082] The assay controls were prepared as follows. A 2 μL aliquot of the 20 mM fluorescence probe compound was diluted 1000-fold in 100 % DMSO to a final concentration of 20 μM. 6 μL of the 20 μM probe was combined with 5.4 mL of the assay buffer, mixed well, and 18 μL of the resulting solution was dispensed into 384-well plates.

[0083] SFRP-I /probe complex was prepared by combining 11 μL of 20 μM probe compound with 9.9 mL of the assay buffer and SFRP-I stock solution to final concentrations of 22 nM probe compound and 50 nM SFRP-I. 18 μL of the SFRP-1/probe complex was dispensed into the 384-well plates.

[0084] 2 μL aliquots of the test compounds from the 10x working stock solutions were removed and dispensed into the plate containing the SFRP-1/probe complex and the resultant solutions were mixed by pipetting up and down once. The final concentratons of SFRP-I and probe in the assay solutions were 45 nM and 20 nM, respectively. In a typical experiment, each plate was used to test 14 compounds.

[0085] The plate was incubated in the dark for 15 minutes. The fluorescence of the SFRP-1/probe complexs was read in the Tecan Ultra plate reader at excitation and emission maxima of 485 and 535 nm. The plate reader settings were as follows:

Mode: Fluorescence Polarization Plate definition: Matrical3841v.pdf (pdf stands for Plate Definition File) Excitation 485nm (bandwidth 20nm) Emission 535nm (bandwidth 30nm)

G-factor: 1.03 # flashes / well: 10 integration time: lOOus time btwn move, flash: 60ms Z-position: 10730 um

Analysis of Results

[0086] Fluorescence anisotropy results from the emission of polarized light in the parallel and perpendicular directions when a fluorophore is excited with vertically polarized light. The anisotropy of the probe in the free and bound state was determined using the following equation: r = /(//)-/(±)í/(//) + 2/(±) where I(II) and 1(1) are the parallel and perpendicular emission intensities, respectively.

[0087] Monitoring the anisotropy changes of the probe compound revealed that it bound saturably to SFRP-I with a K _D of 20-30 nM. The binding affinity was independently verified using a tryptophan fluorescence quenching assay.

[0088] The decrease in the anisotropy of the probe upon addition of the competing test compound was fitted to a sigmoidal dose response curve of the equation shown below: _{v r} , (Top - Bottom) _rτ ... ,

Y = Bottom + _v , ' * Hi slope

(l + lO ^x'Log!C5 °) where "X" is the logarithm of concentration, "Y" is the anisotropy, and "Bottom" and "Top" correspond to the anisotropy values of the free and SFRP-I -bound probe prior to the addition of the test compound, respectively.

[0089] For automated IC 50 determinations, the equation shown above was used in the program GraphPad Prism. The "Hillslope" was kept constant at 1. The value for "Bottom" was fixed, but was determined by the blank (probe-only) wells in the plate. The values for "Top" and "IC50" were determined by the data fit. The value for "Top" was typically close to 120, equivalent to approximately 50 % bound probe, and the value for "Bottom" was around 30, due to free probe. If the test compound interfered with the probe in the fluorescence assay at high concentrations, the range for the fitted data was limited to the lower concentration range.

[0090] The data obtained from the experiments are shown in the table following example 19.

Example 19: Cell-based Assay for in vitro Measurement of SFRP-1/SARP2 Antagonist Activity

[0091] The following cell-based assay can be used to identify inhibitors of SFRP-I . Materials and Methods

Cells

[0092] The osteosarcoma cell line, U2OS (ATCC, HTB 96), was passaged twice a week with growth medium (McCoy's 5A medium containing 10% (v/v) fetal calf serum, 2mM GlutaMAX-1, and 1% (v/v) Penicillin- Streptomycin). The cells were maintained in vented flasks at 37 ⁰ C inside a 5% CO ₂ /95% humidified air incubator. One day prior to transfection, the cells were plated with growth medium at 25,000 cells/well into 96-well plates and incubated at 37 ⁰ C overnight.

Routine Co-Transfection

[0093] The growth medium was removed, and the cells were washed once with OPTIMEM I (Gibco-BRL) medium (100 μL/well) to remove the serum and antibiotics. The wash medium was removed, and the cells were re-fed with OPTI-MEM I medium (100 μL/well). For each well of cells to be transfected, the following DNA 's were diluted together in 25 μL OPTI-MEM I medium: 0.1 μg 16x TCF-tk-Luciferase reporter, 0.02 μg Wnt 3, Wnt3A, Wnt 1 or empty vector (Upstate Biotechnology), 0.075 μg hSFRP-1 or empty vector (pcDNA3.1, Invitrogen), and 0.025 μg CMV-βgal (Clonetech). For each well of cells to be transfected, lμl of Lipofectamine 2000 reagent (Invitrogen) was diluted in 25 μl OPTI-MEM I medium and incubated at room temperature for 5 minutes. The diluted DNA's were then combined with the diluted Lipofectamine 2000 (LF2000), and the mixture was incubated at room temperature for 20 minutes. Fifty μL of the DNA-LF 2000 mixture was added to each well, and the plate(s) were incubated at 37 ⁰ C in a 5% Cθ ₂ /95% humidified air incubator for 4 hours. The cells were washed once with 150 μL/well of experimental medium (phenol red-free RPMI Medium 1640 containing 2% fetal bovine serum, 2mM GlutaMAX-1, and 1% Penicillin-Streptomycin). Finally, the cells were treated overnight at 37 ⁰ C with 200 μL/well of experimental medium containing either vehicle (typically DMSO) or diluted compound in replicates of 8 wells/compound.

Dosing

[0094] Initial single dose screening of test compounds was done at 10 μM .

[0095] Dose-response experiments were initially performed with the compounds in log increases of concentration from 1-10,000 nM. From these dose-response curves, ECso values were generated.

Assay

[0096] After treatment, the cells were washed twice with 150 μL/well of PBS without calcium or magnesium and were lysed with 50 μL/well of IX cell culture lysis reagent (Promega Corporation) on a shaker at room temperature for 30 minutes. Thirty μL aliquots of the cell lysates were transferred to 96-well luminometer plates, and luciferase activity was measured in a MicroLumat PLUS luminometer (EG&G Berthold), or a Victor (PerkinElmer Life Sciences) using 100 μL/well of luciferase substrate (Promega Corporation). Following the injection of substrate, luciferase activity was measured for 10 seconds after a 1.6 second delay. Similarly, 10 μL aliquots of the cell lysates were transferred to separate 96-well luminometer plates, and 50 μL of Galacton chemiluminescent substrate (Tropix) was added to each well. The plates were covered and incubated on a rotary shaker at room temperature for one hour, βgal activity was measured in a MicroLumat PLUS luminometer or Victor using 100 μL/well of Light Emission Accelerator (Tropix). Following the injection of the accelerator, βgal activity was measured for 10 seconds after a 1.6 second delay. The luciferase and βgal activity data were transferred from the luminometer to a PC and analyzed using the SAS/Excel program. After the luciferase activity was normalized to βgal, the SAS/Excel program was used to determine the mean and standard deviation of each treatment, to analyze the data for statistical significance, and to determine EC ₅₀ values (see the Table below).

Large-Scale Co-Transfection

[0097] As an alternative to co-transfection in a 96 well plate, the U2OS cells were transfected in T225 flasks and the transfected cells were frozen. The frozen cells were thawed and plated on a 96 well plate and the assay was carried out as detailed above. The growth medium was removed from the T225 flasks, and the cells were washed once with OPTI-MEM I medium (approx. 25 ml/flask) to remove the serum and antibiotics. The wash medium was removed, and the cells were re-fed with OPTI-MEM I medium (59 ml/flask). For each T225 flask of cells to be transfected, the following DNA's were diluted together in 5.9 ml OPTI-MEM

I medium: 70.3 μg 16x TCF-tk-Luciferase reporter, 14.06 μg WNT3, 3 A or Wntl or empty vector, 52.8 μg hSFRP-1 or empty vector, and 17.58 μg CMV-βgal. Separately, for each flask of cells to be transfected, 354 μL of Lipofectamine 2000 reagent (Invitrogen) was diluted in 5.9 mL OPTI-MEM I medium and incubated at room temperature for 5 minutes. The diluted DNA's were then combined with the diluted Lipofectamine 2000 (LF2000), and the mixture was incubated at room temperature for 20 minutes. 11.8 mL of the DNA-LF 2000 mixture was added to each flask, and the flask(s) were incubated at 37 ⁰ C in a 5% CO ₂ /95% humidified air incubator for 4 hours. The medium was removed, and the cells were washed once with approximately 25 mL/flask of phenol red-free RPMI Medium 1640, then re-fed with 50 mL/flask of experimental medium (phenol red-free RPMI Medium 1640 containing 2% fetal bovine serum, 2 mM GlutaMAX-1, and 1% Penicillin- Streptomycin) and incubated at 37 ⁰ C overnight.

Freezing Cells

[0098] The transfected cells were washed twice with 25 mL/flask/wash of PBS without calcium or magnesium. Three ml of Trypsin-EDTA (0.05% Trypsin, 0.53 mM EDTA-4Na) was added to each flask, and the flasks were incubated at room temperature for approximately 5 minutes until the cells were rounded and detached from the surface of the flask(s). The cells were resuspended in 10 mL/flask of phenol red-free RPMI 1640 containing 10% fetal bovine serum and were pipetted up and down several times until a single cell suspension was formed. The resuspended cells were pooled and a 10 μL aliquot was removed and diluted at 1 : 10 in PBS. The diluted cells were counted using a hemacytometer to determine the total number of cells in the pool. The cells were transferred to sterile centrifuge tubes and pelletted at 1500 rpm in a Sorvall RC-3B refrigerated centrifuge at 4 ⁰ C for 5 minutes. The supernatant was aspirated and the cells were resuspended in cold, phenol red-free RPMI 1640 medium containing 50% FBS to a cell density of 2.5E+7 cells/ml. An equal volume of cold, 2x freezing medium (phenol red-free RPMI 1640 medium containing 50% FBS and 15% DMSO) was added slowly, dropwise to the resuspended cells with gentle mixing, resulting in a final cell density of 1.25E+7 cells/mL. The resuspended cells were placed on ice and aliquoted into sterile cryogenic vials. The vials were transferred to a Nalgene Cryo I ⁰ C freezing container (Nalgene catalog # 5100-0001) containing 250 mL isopropyl alcohol. The sealed container was placed in a -80 ⁰ C freezer overnight to freeze the cells at a cooling rate of -1 °C/minute. The frozen cells were then transferred to a - 150 ⁰ C freezer for long-term storage.

Benchtop Assay for Single Dose Confirmation of HTS Hits

[0099] Early in the morning, a vial of frozen transfected cells was thawed, and the cells were resuspended in phenol red-free RPMI 1640 medium to a final cell density of 150,000 cells/ml. The resuspended cells were then plated in white, 96-well polystyrene tissue culture treated CulturPlatesTM (Packard cat. # 6005180) at a volume of 100 μL of cell suspension/well (i.e. 15,000 cells/well). The plates were incubated at 37 ⁰ C inside a 5% CO ₂ /95% humidified air incubator for 6 hours or until the cells were attached and started to spread. Test compounds were then added to the wells (1 well/compound) and the plates were incubated at 37 ⁰ C overnight. After the overnight incubation, luciferase activity was measured using the Luc-Screen Luciferase Assay System (Tropix). Fifty μL of Luc-Screen buffer 1 , warmed to room temperature, was added directly to the cells in the 96-well plates. Fifty μL of Luc-Screen buffer 2, warmed to room temperature, was then added, and the plates were incubated in the dark, at room temperature, for 10 minutes. The plates were transferred to a Packard Top Count Microplate Scintillation and Luminescence Counter (Packard), and the light emission was measured for 10 seconds after a 2 minute delay.

[0100] The luciferase activity data was transferred to a PC and analyzed using the SAS/Excel program as described above. Analysis of Results

[0101] The luciferase data was analyzed using the SAS/Excel program. For the initial single dose experiment, if the compound treatment resulted in increased reporter activity and was specific to SFRP-I inhibition, then the results were reported as fold induction over SFRP-I control. Compounds

[0102] A known inhibitor of GSK-3β, a key enzyme involved in the Wnt signaling pathway, served as an internal control for measurement of the cellular response to Wnt signaling. The inhibition of GSK-3 results in stabilization of β-catenin, leading to up-regulation of LEF/TCF regulated reporter genes.

[0103] The entire disclosure of each patent, patent application, and publication cited or described in this document is hereby incorporated by reference.