PROCESS FOR PREPARATION OF SUBSTANTIALLY OPTICALLY PURE LEVOROTATORY AND DEXTROROTATORY ENANTIOMERS OF CETIRIZINE USING NOVEL INTERMEDIATES

摘要

The present invention relates to a novel and commercially viable process for substantially optically pure levorotatory and dextrorotatory enantiomers of cetirizine intermediate, 1-[(4-chlorophenyl)phenylmethyl]piperazine, thereby producing substantially optically pure levorotatory and dextrorotatory enantiomers of cetirizine and their pharmaceutical acceptable acid addition salts thereof in high purity and in high yield using novel intermediates.