Synthesis and Structure-Activity Relationship of 2-(4-Benzhydryl-1-piperazinyl)-1-phenylethanols as New Calcium Blockers

Abstract

A series of 2-(4-benzhydryl-1-piperazinyl)-1-phenylethanols (4) was synthesized and evaluated for calcium entry-blocking activity, assessed as inhibitory activity on calcium current in rat hippocampal pyramidal neurons by using a patch-clamp technique (10^-5 M), and cerebral visodilating activity, assessed in terms of increase of vertebral blood flow after intravenous administration (1 mg/kg) in anesthetized dogs. Alkoxy substituents on the phenyl ring of the phenylethanol moiety conferred potent calcium entry-blocking activity and potent cerebral vesodilating activity.Among these compounds, 4i (NC-1100) was selected as the best analog. Some pharmacological properties of 4i are presented.