Abstract

In a series of 27 compounds, maximal anticurare activity and minimal toxicity was found for 3-hydroxyphenyldimethylethylammonium bromide, Ro 2-3198. This compound has slight effects on blood pressure and low activity on intestine and other smooth muscles and low anticliolinesterase activity. It has equal anticurare activity hut lower toxicity than 3-hydroxyphenyltrimethylammonium bromide, Ro 2-2561. Further ethylation or substitution of heavier groups decreased activity. Anticurare activity was unimproved by substitution of methyl groups in the phenol ring. It was decreased by substitution of hydroxyl groups in the 2- and 4-positions and substitution of amino, chlorine or methoxy groups for the 3-hydroxyl group.