Piperidine Derivatives, Their Process for Preparation, Their Use as Therapeutic Agents and Pharmaceutical Compositions Containing Them

A compound of formula (I):

• wherein:
• Ar1 is phenyl or naphthyl, either of which is optionally substituted by chloro, fluoro, methyl or CF3;
• Ar2 is phenyl, naphthyl, imidazolyl, pyrazinyl, thienyl, thiazolyl, thiadiazolyl, pyridinyl, pyrimidinyl, benzimidazolyl, quinolinyl, quinazolinyl, isoquinolinyl, 5-phenylamino-1,3,4-oxadiazolyl, dihydroquinazolinyl, 3-pyridinyl-1,2,4-oxadiazolyl, pyridazinyl or quinoxalinyl;
• wherein Ar2 is substituted by CO2R′ or tetrazolyl;
• and Ar2 is optionally additionally substituted by one or more of halogen, hydroxy, nitro, S(O)r(C1-6 alkyl), S(O)2NH2, S(O)2NH(C1-6 alkyl), S(O)2N(C1-6 alkyl)2, NH2, NH(C1-6 alkyl), N(C1-6 alkyl)2, cyano, C1-6 alkyl, C1-6 alkoxy, C(O)NH2, C(O)NH(C1-6 alkyl), C(O)N(C1-6 alkyl)2, CO2H, CO2(C1-6 alkyl), NHC(O)(C1-6 alkyl), NHS(O)2(C1-6 alkyl), C(O)(C1-6 alkyl), CF3 or OCF3;
• wherein alkyl or alkoxy groups are optionally substituted by NR1R2;
• R1 and R2 are independently hydrogen or C1-4 alkyl or together with the nitrogen to which they are attached form a ring (for example azepine, pyrrolidine, piperidine,
• homopiperidine, morpholine or piperazine), the latter optionally substituted on the distal nitrogen by C1-4 alkyl;
• R′ is hydrogen, C1-6 alkyl or phenyl(C1-4 alkyl);
• wherein the phenyl is optionally substituted with halogen, hydroxy, nitro, S(O)t(C1-4 alkyl), S(O)2NH2, S(O)2NH(C1-4 alkyl), S(O)2N(C1-4 alkyl)2, cyano, C1-4 alkyl, C1-4 alkoxy, C(O)NH2, C(O)NH(C1-4 alkyl), C(O)N(C1-4 alkyl)2, CO2H, CO2(C1-4 alkyl), NHC(O)(C1-4 alkyl), NHS(O)2(C1-4 alkyl), C(O)(C1-4 alkyl), CF3 or OCF3;
• or CO2R′ is (CO2—)pRp+ wherein Rp+ is a univalent cation (for example an alkali metal cation) or two carboxylates may coordinate to a divalent cation (for example an alkaline earth metal cation);
• or tetrazolyl is (tetrazolylg−)Rg+ wherein Rg+ is a univalent cation (for example an alkali metal cation) or two tetrazoles may coordinate to a divalent cation (for example an alkaline earth metal cation);
• and,
• r and t are, independently, 0, 1 or 2;
• or a pharmaceutically acceptable salt thereof;
• provided:
• that when Ar1 is 3,4-difluorophenyl then Ar2 is not 2-(CO2CH3)phenyl.