5,6-DIARYL-PYRAZINE-2-AMIDE DERIVATIVES AS CB1 ANTAGONISTS

The present invention relates to compounds of formula (I), and pharmaceutically acceptable salts, prodrugs, solvates and crystalline forms thereof, in which R1 and R2 independently represent: a C1-6alkyl group; an optionally substituted (amino)C1-4alkyl-group; an optionally substituted non-aromatic C3-15carbocyclic group; a (C3-12cycloalkyl)C1-3alkyl-group; a group -(CH2)r(phenyl)s in which r is 0, 1, 2, 3 or 4, s is 1 when r is 0 otherwise s is 1 or 2 and the phenyl groups are optionally independently substituted by Z; naphthyl; anthracenyl; an optionally substituted saturated 5 to 8 membered heterocyclic group containing one nitrogen and optionally one of the following: oxygen, sulphur or an additional nitrogen; 1-adamantylmethyl; a group -(CH2)t Het in which t is 0, 1, 2, 3 or 4, and the alkylene chain is optionally substituted and Het represents an optionally substituted aromatic heterocycle; or R1 represents H and R2 is as defined above; or R1 and R2 together with the nitrogen atom to which they are attached represent a saturated optionally substituted 5 to 8 membered heterocyclic group as defined above; X is CO or SO2; Y is absent or represents NH optionally substitututed by a C1-3alkyl group; R3 and R4 independently represent phenyl, thienyl or pyridyl substituted by Z; Z represents a C1-3alkyl group, a C1-3alkoxy group, hydroxy, halo, trifluoromethyl, trifluoromethylthio, trifluoromethoxy, trifluoromethylsulphonyl, nitro, amino, mono or di C1-3alkylamino, mono or di C1-3alkylamido, C1-3alkylsulphonyl, C1-3alkoxycarbonyl, carboxy, cyano, carbamoyl, mono or di C1-3alkyl carbamoyl, sulphamoyl and acetyl; and R5 is H, a C1-3alkyl group, a C1-3alkoxymethyl group, trifluoromethyl, a hydroxyC1-3alkyl group, C1-3alkoxycarbonyl, carboxy, cyano, carbamoyl, mono or di C1-3alkylcarbamoyl, acetyl, or hydrazinocarbonyl of formula -CONHNRaRb; with the provisos; and processes for preparing such compounds, their use in the treatment of obesity, psychiatric and neurological disorders, to methods for their therapeutic use and to pharmaceutical compositions containing them.