Sympathetic nervous system blocking agents. Investigation of ethyl-, hydroxyethyl-, vinyloxyethyl-, and propargyl-benzyldimethylammonium halides and related compounds.

A series of quaternary benzylamine derivatives has been prepared. They were examined for their ability to block the sympathetic nervous system without also blocking the parasympathetic system. The most active compounds were derivatives of benzyl(vinyloxyethyl)dimethylammonium halide. The o-bromo analog has activity of the same order of magnitude as bretylium. Pharmacological results and structure-activity relationships are discussed.