| abstract |
The present invention relates to a novel method for the preparation of (4R)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carboxamide of the formula 4R (I) and the metabolites of (4S)- and (4R)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carboxamide of the formula (I), of the formulae M1a (S), M1b (R), M2a (S), M2b (R), M3a (S) and M3b (R) and the use thereof. |