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

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 Y1 and Y5 receptor subtype antagonists. They were found to have nanomolar binding affinities for human NPY Y5 receptor, obtaining the lead compound, trans-N-4-[N′-(thiophene-2-carbonyl)hydrazinocarbonyl]cyclohexylmethyl-4-bromobenzenesulfonamide, which binds with a 7.70 nM IC50 to the hY5 receptor.