Studies on agents with vasodilator and beta-blocking activities. I.

A series of hydrazinopyridazine derivatives combined with a beta-blocking side chain were synthesized. When they were given intravenously to anesthetized rats, some of them exhibited both hypotensive and beta-blocking activities. Their structure-activity relationships for hypotensive and beta-blocking activities are discussed. Compound 11c had the best profile and was selected for further study.