In a Parr reactor, Pd/C (10% Pd moistened, 50% water, 24 mg, 0.23 mmol, 0.1 eq.) was suspended in a solution of tert-butyl 4-{4-[4-(1H-indazol-3-yl)-1H-1,2,3-triazol-1-yl]phenyl}-3,6-dihydropyridine-1(2H)-carboxylate (1.0 g; 2.26 mmol; 1.0 eq.) and ammonium formate (2.85 g; 45.2 mmol; 20 eq.) in THF (55 mL). The reaction mixture was stirred for 48 h at 70° C. It was then filtered through a celite pad, the cake was rinsed several times with THF and the filtrate was concentrated to dryness. The resulting residue was partitioned between DCM and water. Organic phase was washed with brine, dried over magnesium sulfate, filtered and concentrated. Purification by flash chromatography on silica (DCM:MeOH, gradient from 100:0 to 95:5) gave the title compound as a white foam (950 mg g; 94.5%). 1H NMR (300 MHz, DMSO-d6) δ 13.36 (brs, 1H), 9.27 (s, 1H), 8.36 (d, J=8.2 Hz, 1H), 8.01-7.93 (m, 2H), 7.61 (d, J=8.4 Hz, 1H), 7.56-7.39 (m, 3H), 7.30-7.20 (m, 1H), 4.27-3.94 (m, 2H), 3.01-2.63 (m, 3H), 1.96-1.70 (m, 2H), 1.69-1.47 (m, 2H), 1.43 (s, 9H). 1H HPLC (max plot) 97.2%; Rt 5.33 min. UPLC/MS: (MS+) 445.2, (MS−) 443.2.
