Synthesis and pharmacological activity of N-alkyl-1,2-diphenylethanolamines.

A series of N-alkyl-1,2-diphenylethanolamines were synthesized and their pharmacological activities evaluated on various mammalian organs and systems. All compounds produced a generalized inhibitory effect on smooth and cardiac muscles and an increase in coronary flow as well as a brief reduction in rabbit blood pressure. The latter effect was not prevented by pretreatment of the animals with atropine, propranolol, or metoprolol. The compounds were devoid of local anesthetic activity and their inhibitions of the contraction of the isolated rabbit intestine and perfused heart were reversed by exogenous calcium ions. It is proposed that the compounds produce their effects through calcium-channel blockade. The inhibitory effects of some of these compounds were comparable to those of a known calcium-channel blocker.