PROCEDE POUR FABRIQUER DU (4S)-4-(4-CYANO-2-METHOXYPHENYL)-5-ETHOXY-2,8-DIMETHYL-1,4-DIHYDRO-1,6-NAPHTHYRIDIN-3-CARBOXAMIDE ET LE PURIFIER EN VUE DE L'UTILISER EN TANT QUE PRINCIPE ACTIF PHARMACEUTIQUE
The invention relates to a new and improved method for preparing (4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carbox-amide of formula (I) and to the production and use of the crystalline modification I of (4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carbox-amide of formula (I).