The present Invention relates to a New process for Preparation of (4R) - 4 - (cyano - 2-methoxyphenyl) - 5 - ethoxy - 2.8 - dimethyl - 1,4 - dihydro - 1Naftiridina - 3 - 6 - carboxamide of formula (i) and 4R metabolites (4S) - and (4R) - 4 - (cyano - 2-methoxyphenyl) - 5 - ethoxy - 2.8 - dimethyl - 1,4 - dihydro - 1.6 - naftiridina - 3 - carboxamide of formula (i),The formulas M1A, M1B (S) (R), (S) M2A, M2B m3a (R), (S) and M3B (R) and use of the same.La presente invención se refiere a un nuevo procedimiento de preparación de (4R)-4-(4-ciano-2-metoxifenil)-5-etoxi-2,8-dimetil-1,4-dihidro-1,6-naftiridina-3-carboxamida de la fórmula 4R (I) y los metabolitos de (4S)- y (4R)-4-(4-ciano-2-metoxifenil)-5-etoxi-2,8-dimetil-1,4-dihidro-1,6-naftiridina-3-carboxamida de la fórmula (I), las fórmulas M1a (S), M1b (R), M2a (S), M2b (R), M3a (S) y M3b (R) y uso de los mismos.
