1007128-30-4Relevant academic research and scientific papers
PROCESS FOR HIGH YIELD PRODUCTION OF CLOPIDOGREL BY RACEMIZATION OF RESIDUAL LIQUID
-
Page/Page column 15, (2008/06/13)
The present invention relates to a process for preparing S-(+)-clopidogrel in high yield by means of racemization of filtrate, and particularly to a process comprising (a) conducting an optical resolution by converting racemic carboxylic acid of clopidogrel to diastereomer salt using (+)-cinchonine, (b) preparing carboxylic acid of S-(+)-clopidogrel by extraction using an appropriate solvent under an acidic condition, (c) preparing optically pure S-(+)-clopidogrel by reacting the carboxylic acid of S-(+)-clopidogrel with methanol, wherein a filtrate, which remains after collecting the diastereomer salt as solid precipitates, is recycled after being converted to a racemic carboxylic acid of clopidogrel via racemization under a basic condition, thereby maximizing the yield of S-(+)-clopidogrel.
PROCESS FOR THE PREPARATION OF S-(+)-CLOPIDOGREL BY OPTICAL RESOLUTION
-
Page/Page column 8; 13-14; 19, (2008/06/13)
The present invention relates to a process for the preparation of S-(+)-clopidogrel by an optical resolution and, more particularly, to a process for the preparation of S-(+)-clopidogrel represented by the following formula 1 with high optical purity by converting a clopidogrel racemic carboxylic acid into a diastereomeric salt using a (+)-cinchonine for optical resolution, extracting an S-(+)-clopidogrel carboxylic acid from the diastereomeric salt using a suitable solvent under an acidic condition and then reacting the S-(+)-clopidogrel carboxylic acid with methanol.
