Captopril prepn. by cyclisation by dehydration - of n-2(s)-3-hydroxy 2-methyl-propionyl S-thio:proline and reaction of prod with an aq. or alcoholic base

摘要

Captopril (I) (1-((25) 3-mercapto-2-methyl propionyl) L-proline) is prepd. by (A) cyclisation by dehydration of N-2(S)-3-hydroxy 2-methylpropionyl S-thioproline (II) in the presence of triphenylphosphine or triethylphosphite and an ester of azidocarboxylic acid HOOC-N=N-COOH to form (4S.9aS)-hexa- hydro 4-methyl 1H.5H-pyrrolo-(2.1-c) (1.4)thiazepine 1.5-dione (III), and (B) reacting the (III) with an aq. or alcoholic base to form the (I). The intermediates N-(2(S)-3-hydroxy 2-methylpropionyl) S-proline (IV) and N-2(S)-3-hydroxy 2-methylpropionyl S-thioproline (II) are claimed as new.