Patent Publication Number: US-6221902-B1

Title: Biphenyl sulfonyl aryl carboxylic acids useful in the treatment of insulin resistance and hyperglycemia

Description:
This application claims the benefit of U.S. Provisional Application No. 60/099,365, which was converted from U.S. patent application Ser. No. 09/076,597, filed May 12, 1998, pursuant to a petition filed under 37 C.F.R. 1.53(c)(2)(i) on Jul. 6, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     The prevalence of insulin resistance in glucose intolerant subjects has long been recognized. Reaven et al ( American Journal of Medicine  1976, 60, 80) used a continuous infusion of glucose and insulin (insulin/glucose clamp technique) and oral glucose tolerance tests to demonstrate that insulin resistance existed in a diverse group of nonobese, nonketotic subjects. These subjects ranged from borderline glucose tolerant to overt, fasting hyperglycemia. The diabetic groups in these studies included both insulin dependent (IDDM) and noninsulin dependent (NIDDM) subjects. 
     Coincident with sustained insulin resistance is the more easily determined hyperinsulinemia, which can be measured by accurate determination of circulating plasma insulin concentration in the plasma of subjects. Hyperinsulinemia can be present as a result of insulin resistance, such as is in obese and/or diabetic (NIDDM) subjects and/or glucose intolerant subjects, or in IDDM subjects, as a consequence of over injection of insulin compared with normal physiological release of the hormone by the endocrine pancreas. 
     The association of hyperinsulinemia with obesity and with ischemic diseases of the large blood vessels (e.g. atherosclerosis) has been well established by numerous experimental, clinical and epidemiological studies (summarized by Stout,  Metabolism  1985, 34, 7, and in more detail by Pyorala et al,  Diabetes/Metabolism Reviews  1987, 3, 463). Statistically significant plasma insulin elevations at 1 and 2 hours after oral glucose load correlates with an increased risk of coronary heart disease. 
     Since most of these studies actually excluded diabetic subjects, data relating the risk of atherosclerotic diseases to the diabetic condition are not as numerous, but point in the same direction as for nondiabetic subjects (Pyorala et al). However, the incidence of atherosclerotic diseases in morbidity and mortality statistics in the diabetic population exceeds that of the nondiabetic population (Pyorala et al; Jarrett  Diabetes/Metabolism Reviews  1989,5, 547; Harris et al, Mortality from diabetes, in  Diabetes in America  1985). 
     The independent risk factors obesity and hypertension for atherosclerotic diseases are also associated with insulin resistance. Using a combination of insulin/glucose clamps, tracer glucose infusion and indirect calorimetry, it has been demonstrated that the insulin resistance of essential hypertension is located in peripheral tissues (principally muscle) and correlates directly with the severity of hypertension (DeFronzo and Ferrannini,  Diabetes Care  1991, 14, 173). In hypertension of the obese, insulin resistance generates hyperinsulinemia, which is recruited as a mechanism to limit further weight gain via thermogenesis, but insulin also increases renal sodium reabsorption and stimulates the sympathetic nervous system in kidneys, heart, and vasculature, creating hypertension. 
     It is now appreciated that insulin resistance is usually the result of a defect in the insulin receptor signaling system, at a site post binding of insulin to the receptor. Accumulated scientific evidence demonstrating insulin resistance in the major tissues which respond to insulin (muscle, liver, adipose), strongly suggests that a defect in insulin signal transduction resides at an early step in this cascade, specifically at the insulin receptor kinase activity, which appears to be diminished (reviewed by Haring,  Diabetalogia  1991, 34, 848). 
     Protein-tyrosine phosphatases (PTPases) play an important role in the regulation of phosphorylation of proteins. The interaction of insulin with its receptor leads to phosphorylation of certain tyrosine molecules within the receptor protein, thus activating the receptor kinase. PTPases dephosphorylate the activated insulin receptor, attenuating the tyrosine kinase activity. PTPases can also modulate post-receptor signaling by catalyzing the dephosphorylation of cellular substrates of the insulin receptor kinase. The enzymes that appear most likely to closely associate with the insulin receptor and therefore, most likely to regulate the insulin receptor kinase activity, include PTP1B, LAR, PTPα and SH-PTP2 (B. J. Goldstein,  J. Cellular Biochemistry  1992, 48, 33; B. J. Goldstein,  Receptor  1993, 3, 1-15,; F. Ahmad and B. J. Goldstein  Biochim. Biophys Acta  1995, 1248, 57-69). 
     McGuire et al. ( Diabetes  1991, 40, 939), demonstrated that nondiabetic glucose intolerant subjects possessed significantly elevated levels of PTPase activity in muscle tissue vs. normal subjects, and that insulin infusion failed to suppress PTPase activity as it did in insulin sensitive subjects. 
     Meyerovitch et al ( J. Clinical Invest.  1989, 84, 976) observed significantly increased PTPase activity in the livers of two rodent models of IDDM, the genetically diabetic BB rat, and the STZ-induced diabetic rat. Sredy et al ( Metabolism,  44, 1074, 1995) observed similar increased PTPase activity in the livers of obese, diabetic ob/ob mice, a genetic rodent model of NIDDM. 
     The compounds of this invention have been shown to inhibit PTPases derived from rat liver microsomes and human-derived recombinant PTPase-1B (hPTP-1B) in vitro. They are useful in the treatment of insulin resistance associated with obesity, glucose intolerance, diabetes mellitus, hypertension and ischemic diseases of the large and small blood vessels. 
     DESCRIPTION OF THE INVENTION 
     This invention provides a compound of formula I having the structure                    
     wherein                    
     B is carbon or nitrogen; 
     D is oxygen, sulfur, or nitrogen; 
     E is carbon or nitrogen; 
     X is carbon, nitrogen, oxygen, or sulfur; 
     Y is a bond, methylene, C(O), or CH(OH); 
     Z is CH═CH, nitrogen, oxygen, or sulfur; 
     the dashed line of Q represents an optional double bond; 
     R 1  is alkyl of 1 to 12 carbons, aryl of 6-10 carbon atoms, aralkyl of 7-15 carbon atoms, halogen, trifluoromethyl, alkoxy of 1-6 carbon atoms, Het-alkyl wherein the alkyl moiety contains 1-6 carbon atoms, or aryl of 6-10 carbon atoms mono-, di- or or tri-substituted with trifluoromethyl, alkyl of 1-6 carbon atoms or, alkoxy of 1-6 carbon atoms;                    
     R 7  is alkylene of 1 to 3 carbon atoms, 
     G is oxygen, sulfur or nitrogen; 
     R 2  is hydrogen, alkyl of 1-6 carbon atoms, alkoxy of 1-6 carbon atoms, halogen, or trifluoromethyl; 
     R 3  and R 4  are each, independently, hydrogen, halogen, alkyl of 1-6 carbon atoms, aryl of 6-10 carbon atoms, halogen, trifluoromethyl, alkoxy of 1-6 carbon atoms, aryl of 6-10 carbon atoms mono-, di-, or tri-substituted with trifluoromethyl, alkyl of 1-6 carbon atoms or, alkoxy of 1-6 carbon atoms, nitro, alkylsulfamide; arylsulfamide, cycloalkyl of 3-8 carbon atoms or a heterocyclic ring containing 5 to ring 7 atom rings having 1 to 3 heteroatoms selected from oxygen, nitrogen, or sulfur; 
     R 5  is hydrogen, alkyl of 1-6 carbon atoms, aryl of 6-10 carbon atoms mono-, di-, or tri-substituted with trifluoromethyl, halogen, alkyl of 1-6 carbon atoms, aralkyl of 7-15 carbon atoms, or heteroaryl; 
     R 6  is hydrogen, —OR 5 , or —OCOR 5 ; 
     with the proviso that when R 1  is halogen, Y is a bond, 
     or a pharmaceutically acceptable salt thereof, which are useful in treating metabolic disorders related to insulin resistance or hyperglycemia. 
     Pharmaceutically acceptable salts can be formed from organic and inorganic acids, for example, acetic, propionic, lactic, citric, tartaric, succinic, fumaric, maleic, malonic, mandelic, malic, phthalic, hydrochloric, hydrobromic, phosphoric, nitric, sulfuric, methanesulfonic, napthalenesulfonic, benzenesulfonic, toluenesulfonic, camphorsulfonic, and similarly known acceptable acids when a compound of this invention contains a basic moiety. Salts may also be formed from organic and inorganic bases, preferably alkali metal salts, for example, sodium, lithium, or potassium, when a compound of this invention contains a carboxylate or phenolic moiety, or similar moiety capable of forming base addition salts. 
     Alkyl includes both straight chain as well as branched moieties. Halogen means bromine, chlorine, fluorine, and iodine. It is preferred that the aryl portion of the aryl or aralkyl substituent is a phenyl, naphthyl or 1,4-benzodioxan-5-yl group; with phenyl being most preferred. The aryl moiety may be optionally mono-, di-, or tri-substituted with a substituent selected from the group consisting of alkyl of 1-6 carbon atoms, alkoxy of 1-6 carbon atoms, trifluoromethyl, halogen, alkoxycarbonyl of 2-7 carbon atoms, alkylamino of 1-6 carbon atoms, and dialkylamino in which each of the alkyl groups is of 1-6 carbon atoms, nitro, cyano, —CO 2 H, alkylcarbonyloxy of 2-7 carbon atoms, and alkylcarbonyl of 2-7 carbon atoms. 
     The compounds of this invention may contain an asymmetric carbon atom and some of the compounds of this invention may contain one or more asymmetric centers and may thus give rise to optical isomers and diastereomers. While shown without respect to stereochemistry in Formula I, the present invention includes such optical isomers and diastereomers; as well as the racemic and resolved, enantiomerically pure R and S stereoisomers; as well as other mixtures of the R and S stereoisomers and pharmaceutically acceptable salts thereof. 
     When A is                    
     the following compounds of A are preferred:                    
     It is more preferred that A is                    
     and D is O or S. 
     Similarly, allowed compounds (based on correct number of bonds) of Q can readily be recognized by one skilled in the art. It is more preferred that Q is:                    
     Preferred compounds of this invention are those compounds of Formula I, 
     wherein:                    
     B is —CH—; 
     E is —CH—; 
     D is oxygen or suflur;                    
     Z is CH═CH; 
     X is carbon; 
     or a pharmaceutically acceptable salt thereof. 
     Specifically preferred compounds of the present invention are set forth below: 
     4-[4′-(2-benzyl-benzofuran-3-yl)-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     5-[4′-(2-benzyl-benzofuran-3-yl)-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     4-[4′-(2-benzyl-benzofuran-3-yl)-biphenyl-4-yloxysulfonyl]-benzoic acid 
     3-[4′-(2-benzyl-benzofuran-3-yl)-biphenyl-4-yloxysulfonyl]-benzoic acid 
     4-[4′-(2-benzyl-benzo[b]thiopen-3-yl)-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     4-[4′-(2-benzyl-benzo[b]thiopen-3-yl)-3-bromo-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     4-[4′-(2-benzyl-benzo[b]thiopen-3-yl)-3,5 -dibromo-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     4-[4′-(2-benzyl-benzofuran -3-yl)-3,5-dimethyl-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     4-[4′-(2-benzoyl-benzofuran-3-yl)-3-nitro-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     4-[4′-(2-benzyl-benzofuran-3-yl)-3-bromo-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     4-[4′-(2-benzoyl-benzofuran-3-yl)-3-cyclopentyl-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     4-[4′-(2-benzyl4,5-dimethyl-thiopen-3-yl)-3-bromo-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     4-(4′-benzofuran-3-yl)-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     2-hydroxy-4-{3′-[5-methyl-2-(4-trifluoromethyl-phenyl)-oxazol-4-yl]-biphenyl-4-yloxysulfonyl}-benzoic acid 
     or a pharmaceutically acceptable salt thereof. 
     The compounds of this invention were be prepared according to the following schemes from commercially available starting materials or starting materials which can be prepared using to literature procedures. These schemes show the preparation of representative compounds of this invention.                    
     In Scheme I, commercially available phenols (1; R 2  as defined above) were treated with 4-bromophenacyl bromide (2) in the presence of potassium carbonate to produce ketones (3). Compounds (3) were treated with polyphosphoric acid at high temperatures (150° C.) to afford benzofurans (4) [ref. J. Med. Chem. 1989, 32, 1700-1707]. Benzofurans (4) were coupled with aryl boronic acids of general structure (5; R 3 , R 4  are alkyl, aryl, trifluoromethyl, substituted aryl, nitro, carbocyclic 5 to 7 carbon atoms rings or heterocyclic rings 5 to 7 atom rings with from 1 to 3 heteroatoms selected from oxygen, nitrogen, and sulfur) using the Suzuki protocol [ref. Syn. Comm. 1981, 11, 513-519] to produce biphenyls (6). The aryl boronic acids are either commercially available or can be prepared according to known methodology [ref. J. Org. Chem, 1984, 49, 5237-5243]. Biphenyls (6) were converted to biphenyls (8) using two different synthetic approaches. In the first synthetic approach, biphenyls (6) were treated first with n-BuLi and either aldehydes R 1 CHO or “Weinreb” amides R 1 CON(CH 3 )OCH 3  (R 1  is as defined above with the exception of halogen), and secondly with boron tribromide in dichloromethane to produce biphenyls (8). In the second synthetic approach, biphneyls (6) first converted to biphenyls (7) with boron tribrornide in dichloromethane [ref. J. Org. Chem. 1974, 39, 1427-1429], and then (7) were converted to biphenyls (8) by using n-BuLi and either aldehydes R 1 CHO or “Weinreb” amides R 1 CON(CH 3 )OCH 3 . The required aldehydes and “Weinreb” amides are either commercially available or can be prepared according to known synthetic methodology [ref. Tet. Lett. 1993, 34, 6215-6218]. Biphenyls (8) were converted to biphenyls (9) by reduction of the ketones (Y═CO) using the Wolff-Kishner reduction (NH 2 NH 2 , KOH; ref. Org. Reactions, 1948, 4, 378), or reduction of the secondary hydroxy group (Y═CHOH) with sodium borohydride in trifluoroacetic acid [ref. Syn. Comm. 1990, 20, 487-493].                    
     In Scheme II, the biphenyl boronic acid (11) was prepared from 10 according to known methodology [ref. J. Org. Chem. 1984, 49, 5237-5243] using n-BuLi to generate the aryllithium intermediate which was subsequently treated with triisopropyl borate. Boronic acid (11) was coupled with 3-bromobenzothiophenes (prepared according to reference J. Am. Chem. Soc. 1950, 72, 571-574) using the Suzuki protocol [ref. Syn. Comm. 1981, 11, 513-519] to produce biphenyls (12). Biphenyls (12) were converted to the biphenyls (13) in a similar manner as described in Scheme I for the conversion of biphenyls (6) to biphenyls (9).                    
     In Scheme III, thienyl and furyl aldehydes (14) are either commercially available or can be prepared from substituted furans or thiophenes. Furans or thiophenes undergo metallation at the 2-position with alkyllithium reagents [J. Chem. Soc. Perkin I, 1977, 887] which upon treatment first with a formylating agent (i.e., dimethylformamide), and secondly bromination according to known methodology [ref. J. Am. Chem. Soc. 1950, 72, 571-574] to afford the required compounds (14). Coupling of aldehydes (14) with 4,4′-methoxy biphenyl boronic acid using the Suzuki protocol [ref. Syn. Comm. 1981, 11, 513-519] gave biphenyls (15). Known or easily prepared Grignard Reagents [ref. Chem. Re. 1954, 54, 835] R 1 Mg(Cl or Br) (R 1  is as defined above with the exception of halogen, trifluoromethyl, lower alkoxy) were first treated with aldehydes (14), followed by reduction of the produced methyl-hydroxy compounds with sodium borohydride and trifluoroacetic acid, and then demethylation with boron tribromide in dichoromethane to afford biphenyls (16).                    
     In Scheme IV, the furo[2,3-b]pyridines (18) (R 1  is aryl or alkyl) were prepared according to known methodology [ref. Tet. Lett. 1994, 35, 9355-9358]. Bromination of 18 with Br 2 , in carbon tetrachloride produced 19. Pyridines (19) were converted to biphenyls (20) in a similar manner as described in Scheme I by Suzuki coupling with 4,4′-methoxy biphenyl boronic acid, and demethylation with boron tribromide.                    
     In Scheme V, the chloro-nitro-pyridines (21) were treated with primary amines to produce nitro-pyridines (22). The nitro-pyridines (22) were reduced with tin chloride to anilines (23), which upon treatment with ethyl chloroformate and sodium ethoxide gave imidazolones (24). The imidazolones (24) were converted to the 2-chloro-imidazole[4,5-b]pyridines (25). 2-Chlorobenzimidazoles (26) were alkylated in the presence of sodium hydride to give benzimidazoles (27). Both, the imidazole[4,5-b]pyridines (25), and benzimidazoles (27) were converted to the biphenyls (28) in a similar manner as described in Scheme I by Suzuki coupling with 4,4′-methoxy biphenyl boronic acid, and demethylation with boron tribromide.                    
     In Scheme VI, the biphenyl compounds (29; Y═CO, CH 2, ) can be monobrominated or dibrominated using bromine, potassium acetate and acetic acid. One equivalent of bromine in a high dilution reaction mixture and low temperatures in the range of 5-10° C. afforded predominantly the monobrominated product (30; R 3 , R 4 ═H, Br). The dibrominated product (30; R 3 , R 4 ═Br,Br) was obtained with two equivalents of bromine at room temperature. The Suzuki coupling protocol [ref. Syn. Comm. 1981, 11, 513-519] was used to generate the terphenyls 31 and 32. Coupling of the monobromo compounds (30; R 3 ,R 4 ═H,Br) with boronic acids R 8 -Ar-B(OH) 2 ; (R 8 ═halogen, trifluoromethyl, alkoxy, alkyl, nitro, amino, carboalkoxy) in the present of an inorganic base, for example K 2 CO 3 , Ba(OH) 2 , and palladium (0 or II) catalyst, for example Pd(PPh 3 ) 4 , Pd(OAc) 2 , (dppf)PdCl 2 , produced terphenyls (31; R 3 ═H). Similarly, the dibromo compounds (30; R 3 , R 4 ═Br,Br) can undergo Suzuki coupling to afford either the di-coupled product (32) by using 2 equivalents of boronic acid at high temperatures (100° C.), or the mono-coupled-mono-bromo product (31; R 3 ,R 4 ═Br, Aryl-R 13 ). Both the bromo and dibromo compounds can afford in the same synthetic manner products with various heterocyclic boronic acids, for example thiophene, furan, oxazole, thiazole, pyridine).                    
     In Scheme VII phenols (33) were treated with sulfonyl chlorides (34) in the presence of an inorganic base, for example sodium hydroxide in a polar solvent, for example tetrahydrofuran. The sulfonyl chlorides are commercially available or can be obtained by known sulfonylation protocols, for example treatment of an aromatic or heteroaromatic substrate with chlorosulfonic acid. The W-ring represents an optionally fused phenyl ring, which can be present or absent as defined by Q. The esters of the obtained carboxylic acids can be obtained by the known Fisher esterification protocol.                    
     In Scheme VIII commercially available ketones (1) were treated with hydroxylamine in the presence of sodium acetate to produce oximes (2). Oximes (2) were converted to oxazoles by a known methodology [ref. Tet. Lett. 1980, 21, 2359-2360), where oximes (2) were treated with acetyl chlorides in the presence of pyridine to produce oxazoles (3). Oxazoles (3) were coupled with aryl boronic acids of general structure (4; R 3 , R 4  are alkyl, aryl, trifluoromethyl, substituted aryl, nitro, carbocyclic 5 to 7 carbon atoms rings or heterocyclic rings 5 to 7 atom rings with from 1 to 3 heteroatoms selected from oxygen, nitrogen, and sulfur) using the Suzuki protocol [ref. Syn. Comm. 1981, 11, 513-519] to produce biphenyls (5). The aryl boronic acids are either commercially available or can be prepared according to known methodology [ref. J. Org. Chem, 1984, 49, 5237-5243]. Biphenyls (5) were converted to phenols (6) by treatment with boron tribrornide in dichloromethane [ref. J. Org. Chem. 1974, 39, 1427-1429]. 
     The compounds of this invention are useful in treating metabolic disorders related to insulin resistance or hyperglycemia, typically associated with obesity or glucose intolerance. The compounds of this invention are therefore, particularly useful in the treatment or inhibition of type II diabetes. The compounds of this invention are also useful in modulating glucose levels in disorders such as type I diabetes. 
     The ability of compounds of this invention to treat or inhibit disorders related to insulin resistance or hyperglycemia was established with representative compounds of this invention in the following standard pharmacological test procedure which measures the inhibition of PTPase, and an in vivo standard pharmacological test procedure which measures the blood glucose lowering activity of representative compounds of this invention. 
     Inhibition of Tri-Phosphorylated Insulin Receptor Dodecaphosphopeptide Dephosphorylation by hPTP1B 
     This standard pharmacological test procedure assess the inhibition of recombinant rat protein tyrosine phosphatase, PTP1B, activity using, as substrate, the phosphotyrosyl dodecapeptide corresponding to the 1142-1153 insulin receptor kinase domain, phosphorylated on the 1146, 1150 and 1151 tyrosine residues. The procedure used and results obtained are briefly described below. 
     Human recombinant PTP1B was prepared as described by Goldstein (see Goldstein et al.  Mol. Cell. Biochem.  109, 107, 1992). The enzyme preparation used was in microtubes containing 500-700 μg/ml protein in 33 mM Tris-HCl, 2 mM EDTA, 10% glycerol and 10 mM 2-mercaptoethanol. 
     Measurement of PTPase Activity 
     The malachite green-ammonium molybdate method, as described (Lanzetta et al.  Anal. Biochem.  100, 95, 1979) and adapted for a platereader, is used for the nanomolar detection of liberated phosphate by recombinant PTP1B. The test procedure uses, as substrate, a dodecaphosphopeptide custom synthesized by AnaSpec, Inc. (San Jose, Calif.). the peptide, TRDIYETDYYRK, corresponding to the 1142-1153 catalytic domain of the insulin receptor, is tyrosine phosphorylated on the 1146, 1150, and 1151 tyrosine residues. The recombinant rPTP1B is diluted with buffer (pH 7.4, containing 33 mM Tris-HCl, 2 mM EDTA and 50 mM b-mercaptoethanol) to obtain an approximate activity of 1000-2000 nmoles/min/mg protein. The diluted enzyme (83.25 mL) is preincubated for 10 min at 37° C. with or without test compound (6.25 mL) and 305.5 mL of the 81.83 mM HEPES reaction buffer, pH 7.4 peptide substrate, 10.5 ml at a final concentration of 50 mM, and is equilibrated to 37° C. in a LABLINE Multi-Blok heater equipped with a titerplate adapter. The preincubated recombinant enzyme preparation (39.5 ml) with or without drug is added to initiate the dephosphorylation reaction, which proceeds at 37° C. for 30 min. The reaction is terminated by the addition of 200 mL of the malachite green-ammonium molybdate-Tween 20 stopping reagent (MG/AM/Tw). The stopping reagent consists of 3 parts 0.45% malachite green hydrochloride, 1 part 4.2% ammonium molybdate tetrahydrate in 4N HCl and 0.5% Tween 20. Sample blanks are prepared by the addition of 200 mL MG/AM/Tw to substrate and followed by 39.5 ml of the preincubated recombinant enzyme with or without drug. The color is allowed to develop at room temperature for 30 min. and the sample absorbances are determined at 650 nm using a platereader (Molecular Devices). Sample and blanks are prepared in quadruplicates. 
     Calculations 
     PTPase activities, based on a potassium phosphate standard curve, are expressed as nmoles of phosphate released/min/mg protein. Inhibition of recombinant PTP1B by test compounds is calculated as percent of phosphatase control. A four parameter non-linear logistic regression of PTPase activities using SAS release 6.08, PROC NLIN, is used for determining IC 50  values of test compounds. The following results were obtained. 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Example 
                 IC50 (μM) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 1 
                 0.039 
               
               
                   
                 2 
                 0.026 
               
               
                   
                 3 
                 0.075 
               
               
                   
                 4 
                 0.106 
               
               
                   
                 5 
                 0.354 
               
               
                   
                 6 
                 0.034 
               
               
                   
                 7 
                 0.029 
               
               
                   
                 8 
                 0.178 
               
               
                   
                 9 
                 0.040 
               
               
                   
                 10 
                 0.032 
               
               
                   
                 11 
                 0.028 
               
               
                   
                 12 
                 0.024 
               
               
                   
                 13 
                 0.030 
               
               
                   
                 14 
                 0.193 
               
            
           
           
               
               
               
            
               
                   
                 Phenylarsine oxide 
                 39.7 
               
               
                   
                 (reference standard) 
               
               
                   
                 Sodium orthovanadate 
                 244.8 
               
               
                   
                 (reference standard) 
               
               
                   
                 Ammonium molybdate 
                 8.7 
               
               
                   
                 tetrahydrate 
               
               
                   
                 (reference standard) 
               
               
                   
                   
               
            
           
         
       
     
     The blood glucose lowering activity of representative compounds of this invention were demonstrated in an in vivo standard procedure using diabetic (ob/ob) mice. The procedures used and results obtained are briefly described below. 
     The non-insulin dependent diabetic (NIDDM) syndrome can be typically characterizes by obesity, hyperglycemia, abnormal insulin secretion, hyperinsulinemia and insulin resistance. The genetically obese-hyperglycemic ob/ob mouse exhibits many of these metabolic abnormalities and is thought to be a useful model to search for hypoglycemic agents to treat NIDDM [Coleman, D.: Diabetologia 14: 141-148, 1978]. 
     In each test procedure, mice [Male or female ob/ob (C57 B1/6J) and their lean litermates (ob/+or +/+, Jackson Laboratories) ages 2 to 5 months (10 to 65 g)] of a similar age were randomized according to body weight into 4 groups of 10 mice. The mice were housed 5 per cage and are maintained on normal rodent chow with water ad libitum. Mice received test compound daily by gavage (suspended in 0.5 ml of 0.5% methyl cellulose); dissolved in the drinking water; or admixed in the diet. The dose of compounds given ranges from 2.5 to 200 mg/kg body weight/day. The dose is calculated based on the fed weekly body weight and is expressed as active moiety. The positive control, ciglitazone (5-(4-(1-methylcyclohexylmethoxy)benzyl)-2,4-dione, see Chang, A., Wyse, B., Gilchrist, B., Peterson, T. and Diani, A. Diabetes 32: 830-838, 1983.) was given at a dose of 100 mg/kg/day, which produces a significant lowering in plasma glucose. Control mice received vehicle only. 
     On the morning of Day 4, 7 or 14 two drops of blood (approximetly 50 ul) were collected into sodium fluoride containing tubes either from the tail vein or after decapitation. For those studies in which the compound was administered daily by gavage the blood samples were collected two hours after compound administration. The plasma was isolated by centrifugation and the concentration of glucose is measured enzymatically on an Abbott V. P. Analyzer. 
     For each mouse, the percentage change in plasma glucose on Day 4, 7 or 14 is calculated relative to the mean plasma glucose of the vehicle treated mice. Analysis of variance followed by Dunett&#39;s Comparison Test (one-tailed) are used to estimate the significant difference between the plasma glucose values from the control group and the individual compound treated groups (CMS SAS Release 5.18). 
     The results shown in the table below shows that the compounds of this invention are antihyperglycemic agents as they lower blood glucose levels in diabetic mice. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                   
                   
                 % Change Glucose 
               
               
                   
                 Example 
                 Dose (mg/Kg) 
                 from Vehicle 
               
               
                   
                   
               
             
            
               
                   
                 13 
                  25 
                 −24.6 a   
               
               
                   
                 Ciglitazone 
                 100 
                 −43 
               
               
                   
                 (reference 
               
               
                   
                 standard 
               
               
                   
                   
               
               
                   
                   a Statistically (p &lt; 0.05) significant.  
               
            
           
         
       
     
     Based on the results obtained in the standard pharmacological test procedures, representative compounds of this invention have been shown to inhibit PTPase activity and lower blood glucose levels in diabetic mice, and are therefore useful in treating metabolic disorders related to insulin resistance or hyperglycemia, typically associated with obesity or glucose intolerance. More particularly, the compounds of this invention useful in the treatment or inhibition of type II diabetes, and in modulating glucose levels in disorders such as type I diabetes. As used herein, the term modulating means maintaining glucose levels within clinically normal ranges. 
     Effective administration of these compounds may be given at a daily dosage of from about 1 mg/kg to about 250 mg/kg, and may given in a single dose or in two or more divided doses. Such doses may be administered in any manner useful in directing the active compounds herein to the recipient&#39;s bloodstream, including orally, via implants, parenterally (including intravenous, intraperitoneal and subcutaneous injections), rectally, vaginally, and transdermally. For the purposes of this disclosure, transdermal administrations are understood to include all administrations across the surface of the body and the inner linings of bodily passages including epithelial and mucosal tissues. Such administrations may be carried out using the present compounds, or pharmaceutically acceptable salts thereof, in lotions, creams, foams, patches, suspensions, solutions, and suppositories (rectal and vaginal). 
     Oral formulations containing the active compounds of this invention may comprise any conventionally used oral forms, including tablets, capsules, buccal forms, troches, lozenges and oral liquids, suspensions or solutions. Capsules may contain mixtures of the active compound(s) with inert fillers and/or diluents such as the pharmaceutically acceptable starches (e.g. corn, potato or tapioca starch), sugars, artificial sweetening agents, powdered celluloses, such as crystalline and microcrystalline celluloses, flours, gelatins, gums, etc. Useful tablet formulations may be made by conventional compression, wet granulation or dry granulation methods and utilize pharmaceutically acceptable diluents, binding agents, lubricants, disintegrants, suspending or stabilizing agents, including, but not limited to, magnesium stearate, stearic acid, talc, sodium lauryl sulfate, microcrystalline cellulose, carboxymethylcellulose calcium, polyvinylpyrrolidone, gelatin, alginic acid, acacia gum, xanthan gum, sodium citrate, complex silicates, calcium carbonate, glycine, dextrin, sucrose, sorbitol, dicalcium phosphate, calcium sulfate, lactose, kaolin, mannitol, sodium chloride, talc, dry starches and powdered sugar. Oral formulations herein may utilize standard delay or time release formulations to alter the absorption of the active compound(s). Suppository formulations may be made from traditional materials, including cocoa butter, with or without the addition of waxes to alter the suppository&#39;s melting point, and glycerin. Water soluble suppository bases, such as polyethylene glycols of various molecular weights, may also be used. 
     It is understood that the dosage, regimen and mode of administration of these compounds will vary according to the malady and the individual being treated and will be subject to the judgment of the medical practitioner involved. It is preferred that the administration of one or more of the compounds herein begin at a low dose and be increased until the desired effects are achieved. 
    
    
     The following procedures describe the preparation of representative examples of this invention. 
     EXAMPLE 1 
     4-[4′-(2-Benzal-benzofuran-3-yl)-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     Step a) ω-Phenoxy-4-bromoacetophenone 
     Potassium carbonate (24.8 g, 179.8 mmol) was added into a mixture of 2,4′-dibromoacetophenone (50.0 g, 179.8 mmol), phenol (16.9 g, 179.8 mmol) and dry acetone (200 mL). The reaction mixture was refluxed for 12 hours, cooled to room temperature, poured into water, and extracted with ethyl ether. The organic extracts were dried over MgSO 4 . Evaporation gave a yellow solid (49.6 g, 94% yield): MS m/e 291 (M + ). 
     Step b) 3-(4-Bromophenyl)-1-benzofuran 
     A mixture of ω-phenoxy-4-bromoacetophenone (49.0 g, 167.8 mmol), polyphosphoric acid (100 g) and xylenes (300 mL) was refluxed for 12 hours. The reaction mixture cooled to room temperature, poured into water, and extracted with ethyl ether. The organic extracts were dried over MgSO 4 . Evaporation and purification by flash chromatography on silica gel (hexanes/EtAOc 40:1) gave a yellow solid (36.2 g, 79% yield): mp 70-71° C.; MS m/e 272 (M + ); 
     Analysis for: C 14 H 9 BrO Calc&#39;d: C, 61.57; H, 3.32; Found: C, 61.80; H, 3.31 
     Step c) 3-(4′-Methoxy-biphenyl-4-yl)-benzofuran 
     4-Methoxy-benzeneboronic acid (14.17 g, 70.5 mmol) in ethyl alcohol (10 mL) was added into a mixture of 3-(4-bromophenyl)-1-benzofuran (17.5 g, 64.1 mmol), sodium carbonate (2N, 64.1 mL), tetrakis(triphenylphosphine)palladium(0) (2.23 g, 1.92 mmol), and toluene (200 mL). The reaction mixture was refluxed for 12 hours, cooled to room temperature, and treated with hydrogen peroxide (30%, 5 mL) for 1 hour. Then, the mixture was poured into water and extracted with ethyl acetate. The organic extracts were dried over MgSO 4 . Evaporation and crystallization from acetone/ethyl ether gave a white solid (14.9 g, 77% yield): mp 137-138° C.; MS m/e 300 (M + ); 
     Analysis for: C 21 H 16 O 2  Calc&#39;d: C, 83.98; H, 5.37 Found: C, 83.70; H, 5.22 
     Step d) 4′-Benzofuran-3-yl-biphenyl-4-ol 
     Boron tribromide (1.0 M, 6.67 mL, 6.67 mmol) was added dropwise into a cold (−78° C.) mixture of 3-(4′-methoxy-biphenyl-4-yl)-benzofuran (2.0 g, 6.67 mmol), and dichloromethane (25 mL). The reaction mixture was allowed to come gradually to room temperature and stirred for 10 hours. Then the mixture was cooled to 0° C. and methyl alcohol (5 mL) was added dropwise. After stirring for 10 minutes the mixture was poured into water and extracted with ethyl ether. The organic extracts were dried over MgSO 4 . Evaporation and crystallization from ethyl ether/hexanes gave a yellow solid (1.69 g, 87% yield): mp 174-175; MS m/e 286 (M + ); 
     Analysis for: C 20 H 14 O 2  Calc&#39;d: C, 83.90; H, 4.93 Found: C, 83.69; H, 4.88 
     Step e) [3-(4′-Hydroxy-biphenyl-4-yl)-benzofuran-2-yl]-phenyl-methanone 
     n-Butyllithium (2.5 N, 8.4 mL, 20.98 mmol) was added dropwise into a cold (−78° C.) mixture of 4′-benzofuran-3-yl-biphenyl-4-ol (3.0 g, 10.49 mmol) and tetrahydrofuran (50 mL). The mixture was allowed to gradually warm up to −40° C. and stirred for 3 hours. N-Methoxy N-methyl benzamide (1.6 mL, 10.49 mmol) was added dropwise into the mixture. The reaction mixture was allowed to gradually warm up to 0° C. and stirred for 30 minutes. The reaction was quenched with aqueous ammonium chloride, poured into water, acidified with HCl (2N); and extracted with ethyl acetate. The organic extracts were dried over MgSO 4 . Evaporation and crystallization from ethyl ether/hexanes gave a yellow solid (2.9 g, 71% yield): mp 231-232; MS m/e 390 (M + ); 
     Analysis for: C 27 H 18 O 3  Calc&#39;d: C, 83.06; H, 4.65 Found: C, 82.63; H, 4.27 
     Step f) 4′-(2-Benzyl-benzofuran-3-yl)-biphenyl4-ol 
     Hydrazine monohydrate (1.38 g, 27.68 mmol) was added into a mixture of [3-(4′-hydroxy-biphenyl-4-yl)-benzofuran-2-yl]-phenyl-methanone (2.7 g, 6.92 mmol) and diethylene glycol (20 mL). The reaction mixture was stirred at 180° C. for 1 hour. The mixture cooled to room temperature and potassium hydroxide (1.16 g, 20.76 mmol) was gradually added. The mixture stirred at 130° C. for 10 hours, cooled to room temperature, poured into water, and extracted with ethyl ether. The organic extracts were dried over MgSO 4 . Evaporation and crystallization from ethyl ether/hexanes/acetone gave a white solid (2.45 g, 94% yield): mp 151-153; MS m/e 376 (M + ); 
     Analysis for: C 27 H 20 O 2  Calc&#39;d: C, 86.15; H, 5.36 Found: C, 85.88; H, 5.13 
     Step g) 4-[4′-(2-Benzyl-benzofuran-3-yl)-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     Sodium hydroxide (50%) was added dropwise into cold (0° C.) mixture of 4′-(2-benzyl-benzofuran-3-yl)-biphenyl-4-ol (1.0 g, 2.66 mmol), 4-chlorosulfonyl-2-hydroxy-benzoic acid (1.25 g, 5.32 mmol) and tetrahydrofuran (50 mL), in an addition rate that the reaction was maintained at pH 11. The reaction was stirred for 30 minutes, poured into water, acidified with HCl (2N), and extracted with ethyl ether. The organic extracts were dried over MgSO 4 . Evaporation and purification by flash chromatography on acidic silica gel (hexanes/EtAOc 2:1) gave a white solid, (0.67 g, 43% yield): mp 96-98° C.; MS m/e 575 (M-H) + ; 
     Analysis for: C 34 H 24 O 7 S×0.5 H 2 O Calc&#39;d: C, 69.73; H, 4.30 Found: C, 69.83; H, 4.37 
     EXAMPLE 2 
     5-[4′-(2-Benzyl-benzofuran-3-yl)-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     The title compound was prepared from of 4′-(2-benzyl-benzofuran-3-yl)-biphenyl-4-ol and 5-chlorosulfonyl-2-hydroxy-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as a white solid, mp 171-173° C.; MS m/e 575 (M-H) + ; 
     Analysis for: C 34 H 24 O 7 S×0.5 H 2 O Calc&#39;d: C, 69.73; H, 4.30 Found: C, 69.86; H, 4.57 
     EXAMPLE 3 
     4-[4′-(2-Benzyl-benzofuran-3-yl)-biphenyl-4-yloxysulfonyl]-benzoic acid 
     The title compound was prepared from 4′-(2-benzyl-benzofuran-3-yl)-biphenyl-4-ol and 4-chlorosulfonyl-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as a white solid, mp 186-188° C.; MS m/e 559 (M-H) + ; 
     Analysis for: C 34 H 24 O 6 S×0.25 H 2 O Calc&#39;d: C, 72.26; H, 4.37 Found: C, 72.25; H, 4.17 
     EXAMPLE 4 
     3-[4′-(2-Benzyl-benzofuran-3-yl)-biphenyl-4-yloxysulfonyl]-benzoic acid 
     The title compound was prepared from of 4′-(2-benzyl-benzofuran-3-yl)-biphenyl-4-ol and 3-chlorosulfonyl-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as a white solid, mp 169-171° C.; MS m/e 559 (M-H) + ; 
     Analysis for: C 34 H 24 O 6 S×0.25 H 2 O Calc&#39;d: C, 72.26; H, 4.37 Found: C, 72.20; H, 4.31 
     EXAMPLE 5 
     4-(4′-Benzofuran-3-yl)-biphenyl-4-yloxysulfonyl)-2-hydroxy-benzoic acid 
     The title compound was prepared from 4′-(benzofuran-3-yl)-biphenyl-4-ol and 4-chlorosulfonyl-2-hydroxy-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as an off-white solid, mp 218-220° C.; MS m/e 485 (M-H) + ; 
     Analysis for: C 27 H 18 O 7 S Calc&#39;d: C, 66.66; H, 3.73 Found: C, 66.66; H, 3.47 
     EXAMPLE 6 
     4-[4′-(2-Benzyl-benzofuran-3-yl)-3,5-dimethyl-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     The title compound was prepared from 4′-(2-benzyl-benzofuran-3-yl)-3,5-dimethyl-biphenyl-4-ol and 4-chlorosulfonyl-2-hydroxy-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as a white solid, mp 165-167° C.; MS m/e 603 (M-H) + ; 
     Analysis for: C 36 H 28 O 7 S×0.5 H 2 O Calc&#39;d: C, 70.46; H, 4.76 Found: C, 70.53; H, 4.58 
     EXAMPLE 7 
     4-[4′-(2-Benzyl-benzofuran-3-yl)-3-nitro-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     Step a) 4′-(2-Benzyl-benzofuran-3-yl)-3-nitro-biphenyl-4-ol 
     Iron (III) nitrate nonahydrate (8.04 g, 19.9 mmol) was added to a solution of 4′-(2-benzyl-benzofuran-3-yl)-biphenyl-4-ol (6.8 g, 18.1 mmol) in absolute ethanol (80 mL), and the mixture was heated to 45° C. for 1.5 hour. The reaction mixture was cooled to room temperature and poured into HCl (0.1N) and extracted with ethyl acetate 3 times. The extract was washed with brine, dried over MgSO 4  and concentrated in vacuo. Purification by flash chromatography (10% EtOAc/petroleum ether) gave the title compound as a yellow solid, mp 75° C.; MS m/e 420 (M-H) + . Analysis for C 27 H 19 NO 4 .0.5 H 2 O: Calcd. C, 75.34; H, 4.68; N, 3.25. Found: C, 75.6; H, 4.51; N, 3.11. 
     Step b) 4-[4′-(2-benzyl-benzofuran-3-yl)-3-nitro-biphenyl-4-yloxysulfonyl]-2-hydroxy -benzoic acid 
     The title compound was prepared from 4′-(2-benzyl-benzofuran-3-yl)-3-nitro-biphenyl-4-ol and 4-chlorosulfonyl-2-hydroxy-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as a yellow solid, mp 200° C.; MS m/e 620 (M-H) + ; 
     Analysis for: C 34 H 23 NO 9 S Calc&#39;d: C, 62.9; H, 3.54; N, 2.2 Found: C, 62.85; H, 3.9; N, 2.02 
     EXAMPLE 8 
     4-[4′-(2-Benzoyl-benzofuran-3-yl)-3-nitro-biphenyl-4-yloxsulfonyl]-2-hydroxy -benzoic acid 
     The title compound was prepared from 4′-(2-benzoyl-benzofuran-3-yl)-3-nitro -biphenyl-4-ol and 4-chlorosulfonyl-2-hydroxy-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as a yellow solid, mp 105-107° C.; MS m/e 683 (M-H) + ; 
     Analysis for: C 34 H 21 NO 10 S×.55 EtOAc Calc&#39;d: C, 63.56; H, 3.74; N, 2.05 Found: C, 61.91; H, 3.7; N, 1.93 
     EXAMPLE 9 
     4-[4′-(2-Benzoyl-benzofuran-3-yl)-3-cyclopentyl-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     The title compound was prepared from 4′-(2-benzoyl-benzofuran-3-yl)-3-cyclopentyl-biphenyl-4-ol and 4-chlorosulfonyl-2-hydroxy-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as a yellow solid, mp 105-108° C.; MS m/e 694 (M-H) + ; 
     Analysis for: C 39 H 30 O 8 S×0.33 EtOAc×0.44 H 2 O Calc&#39;d: C, 69.61; H, 4.86 Found: C, 67.37; H, 4.68 
     EXAMPLE 10 
     4-[4′-(2-Benzyl-4,5-dimethyl-thiophen-3-yl)-biphenyl-4-yloxsulfonyl]2-hydroxy-benzoic acid 
     The title compound was prepared from 4′-(2-benzyl-4,5-dimethyl-thiophen-3-yl)-biphenyl-4-ol and 4-chlorosulfonyl-2-hydroxy-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as a white solid, mp 173-175° C.; MS m/e 570 (M-H) + ; 
     Analysis for: C 32 H 26 O 6 S 2 ×0.4 H 2 O Calc&#39;d: C, 66.51; H, 4.67 Found: C, 66.47; H, 4.55 
     EXAMPLE 11 
     4-[4′-(2-Benzyl-benzo[b]thiophen-3-yl)-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     Step a) 3-(4′-Methoxy-biphenyl-4-yl)-benzo[b]thiophene 
     Palladium (II) acetate was added into a mixture of 3-bromo-benzo[b]-thiophene (1.4 g, 6.58 mmol), 4′-methoxy-biphenyl-4-boronic acid (1.5 g, 6.58 mmol), potassium carbonate (2.27 g, 16.45 mmol), acetone (20) and H 2 O (20 mL). The reaction mixture was at 65° C. for 2 h, poured into water, and extracted with ethyl acetate. The organic extracts were dried over MgSO 4  Evaporation and crystallization from ethyl ether/hexanes gave an off-white solid (1.76 g, 85% yield): mp 134-136; MS m/e 316 (M + ); 
     Analysis for: C 21 H 16 OS Calc&#39;d: C, 79.71; H, 5.10 Found: C, 78.98; H, 5.13 
     Step b) 4′-Benzo[b]thiophen-3-yl-biphenyl-4-ol 
     This compound was prepared from 3-(4′-methoxy-biphenyl-4-yl) -benzo[b]thiophene, in substantially the same manner, as described in Example 1 step d, and was obtained as an off-white solid, mp 167-169° C.; MS m/e 302 (M + ); 
     Analysis for: C 20 H 14 OS Calc&#39;d: C, 79.44; H, 4.67 Found: C, 79.36; H, 4.52 
     Step c) [3-(4′-Hydroxy-biphenyl-4-yl)-benzo[b]thiophen-2-yl]-phenyl-methanone 
     This compound was prepared from 4′-benzo[b]thiophen-3-yl-biphenyl-4-ol, in substantially the same manner as described in Example 1 step e, and was obtained as a yellow solid, mp 205-207° C.; MS m/e 406 (M + ); 
     Analysis for: C 27 H 18 O 2 S Calc&#39;d: C, 79.78; H, 4.46 Found: C, 78.95; H, 4.59 
     Step d) 4′-(2-Benzyl-benzo[b]thiophen-3-yl)-biphenyl-4-ol 
     This compound was prepared from[3-(4′-hydroxy-biphenyl-4-yl)-benzo[b]thiophen-2-yl]-phenyl-methanone, in substantially the same manner as described in Example 1 step f, and was obtained as a white solid, mp 178-180° C.; MS m/e 392 (M + ); 
     Analysis for: C 27 H 20 OS Calc&#39;d: C, 81.62; H, 5.14 Found: C, 81.60; H, 5.32 
     Step e) 4-[4′-(2-Benzyl-benzo[b]thiophen-3-yl)-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     The title compound was prepared from 4′-(2-Benzyl-benzo[b]thiophen-3-yl)-biphenyl-4-ol and 4-chlorosulfonyl-2-hydroxy-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as a white solid, mp 236-238° C.; MS m/e 591 (M-H) + ; 
     Analysis for: C 34 H 24 O 6 S 2 ×0.35 H 2 O Calc&#39;d: C, 68.17; H, 4.16; Found: C, 68.18; H 4.44 
     EXAMPLE 12 
     4-[4′-(2-Benzyl-benzo[b]thiophen-3-yl)-3-bromo-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     Step a) 4′-(2-Benzyl-benzo[b]thiophen-3-yl)-3-bromo-biphenyl-4-ol or 4′-(2-Benzyl-benzo[b]thiopen-3-yl)-3,5-dibromo-biphenyl-4-ol 
     Bromine (1.47 mL, 28.69 mmol) in acetic acid (50 mL) was added dropwise over a 30 minutes period into a cold (5° C.) mixture of 4′-(2-benzyl-benzo[b]thiophen-3-yl)-biphenyl-4-ol (7.5 g, 19.13 mmol), potassium acetate (18.6 g, 190.13 mmol), and acetic acid (200 mL). After the addition the mixture was poured into water, and extracted with ethyl ether. The organic extracts were washed with aqueous sodium bisulfite and dried over MgSO 4 . Evaporation and purification by flash chromatography on silica gel (hexanes/EtAOc/CH 2 Cl 2  3:1:1) gave 4′-(2-benzyl-benzo[b]thiophen-3-yl)-3-bromo-biphenyl-4-ol as a light yellow solid (2.4 g): mp 54-56° C. MS m/e 477 (M + ); 
     Analysis for: C 27 H 19 BrOS Calc&#39;d: C, 68.79; H, 4.06 Found: C, 68.37; H, 4.17 
     and 4′-(2-benzyl-benzo[b]thiophen-3-yl)-3,5-dibromo-biphenyl-4-ol as a light yellow solid (4.7 g); mp 59-61° C.; MS m/e 548 (M + ); 
     Analysis for: C 27 H 18 Br 2 OS Calc&#39;d: C, 58.93; H, 3.30 Found: C, 59.21; H, 3.57 
     Step b) 4-[4′-(2-Benzyl-benzo[b]thiophen-3-yl)-3-bromo-biphenyl-4-yloxysulfonyl]-2-hydroxy-benzoic acid 
     The title compound was prepared from 4′-(2-benzyl-benzo[b]thiophen-3-yl)-3-bromo-biphenyl-4-ol and 4-chlorosulfonyl-2-hydroxy-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as an off-white solid, mp 117-119° C.; MS m/e 669 (M-H) + ; 
     Analysis for: C 34 H 23 BrO 6 S 2  Calc&#39;d: C, 60.81; H, 3.45 Found: C, 60.57; H, 3.79 
     EXAMPLE 13 
     4-[4′-(2-Benzyl-benzo[b]thiophen-3-yl)-3,5-dibromo-biphenyl-4-yloxysulfonyll-2-hydroxy-benzoic acid 
     The title compound was prepared from 4′-(2-benzyl-benzo[b]thiophen-3-yl)-3,5-dibromo-biphenyl-4-ol and 4-chlorosulfonyl-2-hydroxy-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as white solid, mp 192-194° C.; MS m/e 747 (M-H) + ; 
     Analysis for: C 34 22 4 Br 2 O 6 S 2  Calc&#39;d: C, 54.42; H, 2.95 Found: C, 55.21; H, 3.76 
     EXAMPLE 14 
     2-Hydroxy-4-{3′-[5-methyl-2-(4-trifluoromethyl-phenyl)-oxazole-4-yl]-biphenyl-4-yoxysulfonyl}-benzoic acid 
     Step a) 1-(4-bromo-phenyl)-propanone oxime 
     Sodium acetate (80.0 g, 976 mmol) was added into a mixture of 1(4-bromo -phenyl)-propanone (52.0 g, 244 mmol), hydroxylamine hydrochloride (50.8 g, 732.3 mmol), ethyl alcohol (500 mL) and water (100 mL). The reaction mixture was stirred at 60° C. for 1 hour, poured into water, and extracted with ethyl ether. The organic extracts were dried over MgSO 4 . Evaporation and crystallization from ethyl ether/hexanes gave a white solid (49.6 g, 89% yield); MS m/e 227(M + ); 
     Analysis for C 9 H 10 BrNO: Calc&#39;d: C, 47.39; H, 4.42; N, 6.14 Found: C, 47.42; H, 4.37; N, 5.99 
     Step b) 4-(4-Bromo-phenyl)-5-methyl-2-(4-trifluoromethyl-phenyl)-oxazole 
     Pyridine (3.55 mL, 43.86 mmol) was added into a mixture of 1-(4-bromo-phenyl)-propanone oxime (10.0 g, 43.86 mmol) and toluene (20 mL). The reaction mixture was stirred for 30 minutes, and then 4-trifluoromethyl-phenyl acetyl chloride (16.27 mL, 109.6 mmol) was added dropwise. The new mixture was stirred at 100° C. for 24 hours, and then was poured into water and extracted with ethyl acetate. The organic extracts were dried over MgSO 4 . Evaporation and purification by flash chromatography on silica gel (hexanes/EtoAc 40:1) gave a white solid (7.3 g, 43% yield): mp 82.84° C.; MS m/e 381 (M + ); 
     Analysis for: C 17 H 11 BrF 3 NO Calc&#39;d: C, 53.43; H, 2.90; N, 3.67 Found: C, 53.47; H, 2.62; N, 3.43 
     Step c) 4-(4′-Methoxy-biphenyl-4-yl)-5-methyl-2-(4-trifluoromethyl-phenyl)-oxazole 
     4-Methoxy-benzeneboronic acid (1.44 g, 7.19 mmol) in ethyl alcohol (5 mL) was added into a mixture of 4-(4-bromo-phenyl)-5-methyl-2-(4-trifluoromethyl-phenyl)-oxazole (2.5 g, 6.54 mmol), sodium carbonate (2N, 6.5 mL), tetrakis(triphenylphosphine)palladium(0) (0.23 g, 0.196 mmol), and toluene (200 mL). The reaction mixture was refluxed for 12 hours, cooled to room temperature, and treated with hydrogen peroxide (30%, 5 mL) for 1 hour. Then, the mixture was poured into water and extracted with ethyl acetate. The organic extracts were dried over MgSO 4 . Evaporation and crystallization from hexanes/ethyl ether gave a white solid (2.2 g, 82% yield): mp 167-168° C.; MS m/e 409 (M + ); 
     Analysis for: C 24 H 18 F 3 NO 2  Calc&#39;d: C, 70.41; H, 4.43; N, 3.42 Found: C, 70.14; H, 4.32; N, 3.30 
     Step d) 4′-[5-Methyl-2-(4-trifluoromethyl-phenyl)-oxazole-4-yl]-biphenyl-4-ol 
     Boron tribromide (1.0 M, 3.91 mL, 3.91 mmol) was added dropwise into a cold (−78° C.) mixture of 4-(4′-methoxy-biphenyl-4-yl)-5-methyl-2-(4-trifluoromethyl -phenyl)-oxazole (1.6 g, 3.91 mmol), and dichloromethane (20 mL). The reaction mixture was allowed to come gradually to room temperature and stirred for 10 hours. Then, the mixture was cooled to 0° C. and methyl alcohol (5 mL) was added dropwise. After stirring for 10 minutes the mixture was poured into water and extracted with ethyl ether. The organic extracts were dried over MgSO 4 . Evaporation and crystallization from ethyl ether/hexanes gave an off-white solid (1.4 g, 90% yield): mp 189-191; MS m/e 396 (M+H) + ; 
     Analysis for: C 23 H 16 F 3 NO 2 ×0.3 H 2 O Calc&#39;d: C, 68.92; H, 4.17; N, 3.50 Found: C, 68.97; H, 4.23; N, 3.33 
     Step e) 2-Hydroxy-4-{3′-[5-methyl-2-(4-trifluoromethyl-phenyl)-oxazole-4-yl]-biphenyl-4-yloxysulfonyl}-benzoic acid 
     This compound was prepared from 4′-[5-methyl-2-(4-trifluoromethyl-phenyl)-oxazole-4-yl]-biphenyl-4-ol and 4-chlorosulfonyl-2-hydroxy-benzoic acid, in substantially the same manner, as described in Example 1 step g, and was obtained as white solid, mp 216-218° C.; MS m/e 594 (M-H) + ; 
     Analysis for: C 30 H 20 F 3 NO 7 S Calc&#39;d: C, 60.50; H, 3.38; N, 2.35 Found: C, 60.11; H, 3.28; N, 2.29