Novel potent antagonists of human neuropeptide Y-Y5 receptor. Part 4: tetrahydrodiazabenzazulene derivatives

Novel tetrahydrodiazabenzazulene derivatives, designed from the lead compound 1 discovered by screening of our in-house chemical library, were prepared and found to be potent neuropeptide Y-Y5 (NPY-Y5) receptor antagonists. The structure–activity relationships are described. Compounds 7 (FR240662) and 16 (FR252384) were especially attractive owing to their high affinities for the NPY-Y5 receptors, oral absorption and permeability to brain.