Synthesis and SAR study of new phenylimidazole-pyrazolo[1,5-c]quinazolines as potent phosphodiesterase 10A inhibitors

A series of phenylimidazole-pyrazolo[1,5- c ]quinazolines 1a – q was designed, synthesized and characterised as a novel class of potent phophodiesterase 10A (PDE10A) inhibitors. In this series, 2,9-dimethyl-5-(2-(1-methyl-4-phenyl-1 H -imidazol-2-yl)ethyl)pyrazolo[1,5- c ]quinazoline ( 1q ) showed the highest affinity for PDE10A enzyme (IC 50 = 16 nM).