Antihypertensive ureidopiperidines

The synthesis of a series of 1-aralkyl-4-ureidopiperidines is reported. These compounds are related to the benzamidopiperidines exemplified by indoramin. Some of the ureidopiperidines are more potent antihypertensive agents than their benzamidopiperidine counterparts. Two examples, 1-(2-thenoyl)-3-[1-[2-(3-indolyl)ethyl]piperid-4-yl]urea and 1-(2-thenoyl)-3-[1-[4-(4-fluorophenyl)-4-oxobutyl]piperid-4-yl]urea (19 and 58), emerged as the most potent antihypertensive agents in this series.