The design and synthesis of the Angiotensin Converting Enzyme inhibitor Cilazapril and related bicyclic compounds

Abstract
The postulated binding functions for the active site of Angiotensin Converting Enzyme (A.C.E.), derived in an earlier study, have made possible the design of improved inhibitors. Consequently, (1S,9S)-9-[(1S)-(ethoxycarbonyl)-3-phenylpropylamino]octahydro-10-oxo-6H-pyridazo[1,2-a][1,2]diazepine-1-carboxylic acid (Cilazapril), and related compounds, have been synthesized. They are very active inhibitors of A.C.E. and are highly potent antihypertensives in vivo.