PROCESS FOR PREPARATION OF (4S) - 4- (4-CYANO-2-METHOXYPHENYL) -5-ETHOXY-2,8-DIMETHYL-1,4-DIHYDRO-1,6-NAPHTHYRIDINE-3-CARBOXAMIDE BY RACEMATE RESOUTION THROUGH DIASTEREOMERIC TARTARIC ACID

摘要

The present invention relates to a new and improved process for the preparation of (4S) -4- (4-cyano-2-methoxyphenyl) -5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine 3-carboxamide amide of the formula (I) and the preparation of the enantiomer (Ia) by a racemate resolution with chiral substituted tartaric acid esters of the general formulas (IIIa) and (IIIb) Where Ar is a substituted or unsubstituted aromatic or heteroaromatic.