EP3337801A1 - METHOD FOR THE PREPARATION OF (4S)-4-(4-CYANO-2-METHOXYPHENYL)-5-ETHOXY-2,8-DIMETHYL-1,4-DIHYDRO-1-6-NAPHTHYRIDINE-3-CARBOXAMIDE AND RECOVERY OF (4S)-4-(4-CYANO-2-METHOXYPHENYL)-5-ETHOXY-2,8-DIMETHYL-1,4-DIHYDRO-1-6-NAPHTHYRIDINE-3-CARBOXAMIDE BY ELECTROCHEMICAL METHODS