Synthesis and antihypertensive activity of 2-benzamido-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizines.

The synthesis and antihypertensive activity of a series of 2-benzamido-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]-quinolizines are reported. A number of these compounds exhibit extremely potent hypotensive properties (e.g., N-methylbenzamides 42, 48, and 50 and N-ethylbenzamide 53 cause drops of 110, 103, 79, and 83 mmHg, respectively, in systolic blood pressure in the spontaneous hypertensive rat at the screening dose of 50 mg/kg po). Structure-activity relationships for the entire series are discussed.