Photochemical process for producing (4R,4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridin-3-carboxamide

Abstract

The invention relates to a method for preparing racemic (4R,4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carboxamide of the formula (I) from the enantiomers (Ia) or (Ib); a method for preparing (4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carboxamide of the formula (Ia); a method for preparing racemic (4R,4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carboxamide of the formula (I) from the pyridine of the formula (II). The objects of the invention have in common the irradiation of the compound of the formulae (Ia), (Ib) and/or (II) with light in a suitable solvent, or solvent mixture, in the presence of a base. The compounds of the formulae (Ia), (Ib) and/or (II) are intermediates, by-products or target compounds in the synthesis of finerenone (compound according to formula (Ia)).

Dependencies are inferred from the claim text.