2,3-dihydro-3-(1-pyrryl)spiro[benzofuran-2,4'-piperidine]s and 2,3-dihydro-3-(1-pyrryl)spiro[benzofuran-2,3'-pyrrolidine]s: novel antihypertensive agents

A series of 2,3-dihydro-3-(1-pyrryl)spiro[benzofuran-2,4'-piperidine]s (IV) and 2,3-dihydro-3-(1-pyrryl)spiro[benzofuran-2,3'-pyrrolidine]s (V) was synthesized and evaluated for cardiovascular activity. The majority of the compounds displayed good antihypertensive activity in the spontaneous hypertensive rat model at 50 mg/kg po. Compounds 5 (2,3-dihydro-1'-methyl-3-(1-pyrryl)spiro[benzofuran-2,4'-piperidine] ) and 12a (2,3-dihydro-1'-ethyl-3-(1-pyrryl)-spiro[benzofuran-2,4'-piperidine] ) were selected for a more detailed cardiovascular evaluation in the renal hypertensive rat and for standard cardiovascular challenges in anesthetized dogs and the sinoaortic-deafferented dog.