Synthesis and pharmacological study of new calcium antagonists, analogues of cinnarizine and flunarizine

Several phosphonic diethyl esters were synthesized and their calcium antagonistic activity evaluated in vitro. The diethyl phosphonate group was condensed on substituted [diphenylmethyl], [(2-benzofuranyl)phenylmethyl], [(4-(diphenylmethyl-1-piperazinyl) methyl], [4 (4-diphenylmethyl-1-piperazinyl methyl) phenylmethyl], and [4-(3-phenyl-2-propenyl)-1-piperazinyl methyl] groups. Despite the presence of the diethyl phosphonate moiety and the benzhydrylpiperazinyl group, both present in potent calcium antagonist structures, only 1 of the 19 synthesized compounds exhibited a calcium antagonistic profile.