process for preparing (4s) -4- (4-cyano-2-methoxyphenyl) -5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carboxamide and recovering (4s ) -4- (4-cyano-2-methoxyphenyl) -5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carboxamide by electrochemical methods

摘要

The present invention relates to an innovative process for preparing (4s) -4- (4-cyano-2-methoxyphenyl) -5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine -3-carboxamide of formula (i) and recover (4s) -4- (4-cyano-2-methoxyphenyl) -5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine -3-carboxamide of formula (i) (i), proceeding from (4r) -4- (4-cyano-2-methoxyphenyl) -5-ethoxy-2,8-dimethyl-1,4-dihydro -1,6-naphthyridine-3-carboxamide of the formula then- (i) then- (i).