Novel potent antagonists of human neuropeptide Y Y5 receptors. Part 2: substituted benzo[a]cycloheptene derivatives

Abstract Novel benzo[ a ]cycloheptene derivatives were prepared for the purpose of searching new neuropeptide Y-Y5 (NPY-Y5) receptor antagonists. The structure–activity relationships are described and compound 2o (FR226928) showed the most potent affinity for Y5 receptor of all we prepared and was found to have higher potency and better selectivity for Y5 over Y1 receptor affinities when compared with the known lead compound 1 .