Process for preparing ethyl-alpha-(1-carboxyethyl)-amino-gamma-oxo-gamma-phenylbutyrate.

摘要

A process for preparing ethyl- alpha -(1-carboxy-ethyl)amino- gamma -oxo- gamma -phenylbutyrate, which comprises reacting an alkali metal salt, an alkaline earth metal salt or a quaternary ammonium salt of alanine with ethyl- beta -benzoylacrylate and a process for preparing ethyl- alpha -(1-carboxyethyl)amino- gamma -phenylbutyrate, which comprises catalytically reducing ethyl- alpha -(1-carboxyethyl)amino- gamma -oxo- gamma -phenylbutyrate. According to the process of the present invention and by controlling the conditions of the Michael addition reaction or work-up thereof, ( alpha S, 1S)-ethyl- alpha -(1-carboxyethyl)amino- gamma -oxo- gamma -phenylbutyrate having the formula (I) can be prepared in an extremely high yield starting from low-priced transethyl- beta -benzoylacrylate or cis-ethyl- beta -benzoylacrylate and a metal salt or a quaternary ammonium salt of (S)-alanine. Further, according to the process of the present invention, ( alpha S,1s)-ethyl- alpha -(1-carboxyethyl)amino- gamma -phenylbutyrate having the formula (III), which is an important intermediate compound for preparing angiotensin converting enzyme (ACE) inhibitory agents, can be prepared quite simply and efficiently.