The present invention relates to a novel and improved process for preparing (4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carboxamide of the formula (I)
and also to the preparation of the enantiomer (Ia) by racemate resolution using chiral substituted tartaric acid esters of the general formulae (IIIa) and (IIIb)
where Ar represents a substituted or unsubstituted aromatic or heteroaromatic radical.
本发明涉及一种用于制备(4S)-4-(4-
氰基-2-
甲氧基苯基)-5-乙氧基-2,8-二甲基-1,4-二氢-1,6-
萘啶-3-羧酰胺(I)的新型改进工艺,以及使用手性取代
酒石酸酯(IIIa)和(IIIb)的一般式来进行外消旋分离制备对映体(Ia),其中Ar代表取代或未取代的芳香或杂芳基。