Synthesis of new thiophene and benzo[b]thiophene hydrazide derivatives as human NPY Y5 antagonists

Abstract Neuropeptide Y is one of the most potent appetite stimulating hormones known. Novel thiophene and benzo[ b ]thiophene hydrazide derivatives were synthetized and evaluated biologically as NPY Y 1 and Y 5 receptor subtype antagonists. They were found to have nanomolar binding affinities for human NPY Y 5 receptor, obtaining the lead compound, trans - N -4-[ N ′-(thiophene-2-carbonyl)hydrazinocarbonyl]cyclohexylmethyl-4-bromobenzenesulfonamide, which binds with a 7.70 nM IC 50 to the hY 5 receptor.