To a stirred solution of N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-5-(ethyl(tetrahydro-2H-pyran-4-yl)amino)-2′-fluoro-4′-formyl-4-methyl-[1,1′-biphenyl]-3-carboxamide (300 mg, 0.57 mmol) and morpholine (100 mg, 1.15 mmol) in dichloroethane (4 mL), acetic acid (207 mg, 3.46 mmol) was added and reaction stirred at room temperature for 30 minutes. Then sodium triacetoxyborohydride (367 mg, 1.73 mmol) was added to the reaction mixture at 0° C., allowed to attain room temperature and stirring continued for overnight. On completion, reaction mixture was diluted with dichloromethane, washed with water, saturated aqueous sodium bicarbonate solution and dried over sodium sulphate. Removal of the solvent under reduced pressure followed by column chromatographic purification afforded the title compound (300 mg, 87.97%).
