Procedure for the preparation of (4S) - 4 - (cyano - 2-methoxyphenyl) - 5 - ethoxy - 2.8 - dimethyl - 1,4 - dihydro - 1.6 - naftiridina - 3 - carboxamide and Recovery (4S) - 4 - (cyano - 2-methoxyphenyl) - ethoxy - 5 - 28 - dimethyl - 1,4 - dihydro - 1.6 - naftiridina - 3 - carboxamide through Electrochemical Methods

摘要

The present invention relates to a novel method for the preparation of (4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1-6-naphthyridine-3-carboxamide of the formula (I) and for the recovery of (4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1-6-naphthyridine-3-carboxamide of the formula (I) starting from (4R)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carboxamide of the formula ent-(I).