Process for preparing 1-(3-bromo-2-alkylpropanoyl-L-proline derivatives

摘要

The invention relates to the preparation of 1-bromo-2-D-alkylpropanoyl-L-proline derivatives and analogous compounds which are useful as chemical intermediates to angiotensin converting enzyme (ACE) inhibitors and to the stereospecific synthesis of such ACE inhibitors having the formula: <IMAGE> wherein R1 is lower alkyl and R4 and R5 are both hydrogen or together with the carbons to which they are attached represent a benzene ring optionally substituted by defined substituents. Intermediates of formula <IMAGE> are also disclosed wherein R1, R4, R5 are as defined above and B+ is a cation.