Novel and Highly Selective Postsynaptic α‐Adrenoreceptor Antagonists: Synthesis and Structure‐Activity Relationships of Alkane‐ Bridged (4‐(Phenoxyethyl)‐1‐piperazinyl)‐3(2H)‐pyridazinones.

Summary The synthesis of selected 4-[4-(phenoxyethyl)-1-piperazinyl]-3(2 H )-pyridazinones and alkane-bridged dimers of 4-, 5- and 6-[4-(phenoxyethyl)-1-piperazinyl]-3(2 H )-pyridazinones is reported. The blocking activity of these compounds was determined on the pre- and postsynaptic α-adrenoreceptors of isolated rat vas deferons.