Preparation of (4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine- 3-carboxyguanamine method and its purification for use as a pharmaceutical active ingredient
The present invention relates to a process for preparing (4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4- of the formula (I) Novel and improved method for dihydro-1,6-naphthyridin-3-carboxyguanamine □