CA3158166A1 — Process for the preparation of 2-cyanoethyl (4s)-4-(4-cyano-2-methoxy-phenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carboxylate by resolution of racemates by means of diastereomeric tartaric acid esters

USPTO Abstract

The present invention relates to the diastereomer salts (Va), (Vb), (Vc) and/or (Vd), a process for preparing the diastereomer salts (Va), (Vb), (Vc) and/or (Vd) using a chiral-substituted tartaric acid ester of the formula (IIIa) or (IIIb), a process for preparing the compound according to formula (IVa) using the diastereomer salts (Va), (Vb), (Vc) and/or (Vd), a process for preparing the compound according to formula (VIIa) using the diastereomer salts (Va), (Vb), (Vc) and/or (Vd), a process for preparing the compound according to formula (Ia) using the diastereomer salts (Va), (Vb), (Vc) and/or (Vd), the use of the diastereomer salts (Va), (Vb), (Vc) and/or (Vd) for preparing a compound according to formulae (IVa), (VIIa) and/or (Ia); the use of a chiral-substituted tartaric acid ester of the formulae (IIIa) or (IIIb) for preparing the diastereomer salts (Va), (Vb), (Vc) and/or (Vd), and the use of a chiral-substituted tartaric acid ester of the formulae (IIIa) or (IIIb) for preparing a compound of formulae (IVa), (VIIa) and/or (Ia).