Process for preparing N-acetyl(L)-4-cyanophenylalanine from a mixture of the corresponding D,L ethyl esters using subtilisin

摘要

The present invention is related to a novel process for preparing N-acetyl-(L)-4-cyanophenylalanine by resolving the racemic compound N-acetyl-(D,L)-4-cyanophenylalanine ethyl ester, and a novel process to prepare a stereoisomer of Ac-(L)-pAph-Chg-PalMe(3)-NH2 by using the intermediate N-acetyl-(L)-4-cyanophenylalanine.