3-(Cyclopentyl(methyl)amino)-N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-2-methyl-5-(1,2,3,6-tetrahydropyridin-4-yl)benzamide (0.100 g, 0.223 mmol) was dissolved in methanol (5 mL) and cooled to 0° C., formalin (0.067 g, 0.19 mL, 2.23 mmol) was added. Resulting reaction mass was stirred at same temperature for 30 minutes. Sodium cyanoborohydride (0.041 g, 0.66 mmol) was added to above reaction mass and stirred at room temperature for 4 h. After completion, solvent were removed under reduced pressure and water was added to the residue, extraction was carried out using DCM. Combined organic layers were dried, concentrated and purified by column chromatography to provide the desired compound (0.065 g, 63%): LCMS: 463.40 (M+1)+; HPLC: 98.79% (@ 254 nm) (Rt; 3.911; Method: Column: YMC ODS-A 150 mm×4.6 mm×5μ; Mobile Phase: A; 0.05% TFA in water/B; 0.05% TFA in acetonitrile; Inj. Vol: 10 μL, Col. Temp.: 30° C.; Flow rate: 1.4 mL/min.; Gradient: 5% B to 95% B in 8 min, Hold for 1.5 min, 9.51-12 min 5% B); 1H NMR (DMSO-d6, 400 MHz) δ 11.43 (s, 1H), 8.04 (t, 1H, J=4.8 Hz), 7.17 (s, 1H), 6.95 (s, 1H), 6.07 (s, 1H), 5.85 (s, 1H), 4.25 (d, 2H, J=4.8 Hz), 3.45 (m, 1H), 2.98 (bs, 2H), 2.53 (m, 2H), 2.42 (bs, 2H), 2.26 (s, 3H), 2.18 (s, 3H), 2.17 (s, 3H), 2.10 (s, 3H), 1.67 (m, 2H), 1.59 (m, 2H), 1.49 (m, 2H), 1.40 (m, 2H).
