Process for the preparation of high purity perindopril and intermediates useful in the synthesis

摘要

The present invention relates to a process for the preparation of 1-{2(S)-[1(S)- (ethoxycarbonyl)butylamino]propionyl}-(3aS,7aS)octahydroindol- 2(S)-carboxylic acid of the formula (I) and the t-butylamine salt of the formula (I') thereof free of contaminations derivable from dicyclohexyl carbodiimide and new intermediates of the general formula (III), wherein R stands for lower alkyl or aryl lower alkyl, wherein lower alkyl means a straight or branched chain alkyl group containing 1-6 carbon atoms.