Synthesis of some N-benzhydrylpiperazine derivatives as calcium antagonists.

The preparation of a series of 24 N-benzhydrylpiperazine derivatives is described. Their efficacy as calcium antagonists was examined with reference to changes in the permeability of the cell membrane to extracellular and intracellular calcium. Compounds 14, 15, 17 and 19 were the most powerful when compared with known calcium antagonists such as cinnarizine, flunarizine, and aligeron ([1-diphenylmethyl)-4-(2-propenyl)]-piperazine), and were selected for further study.