反应详情

A mixture of tert-butyl 4-(2-fluoro-6-(trifluoromethyl)phenyl)-5,6-dihydropyridine-1(2H)-carboxylate (21, 0.479 g, 1.41 mmol) and PtO2 (0.095 g, 0.42 mmol) in EtOAc (15 mL) and HOAc (82 μL, 1.4 mmol) stirred at ambient temperature for 72 h under an atmosphere of H2 (1 atm). The mixture was diluted with EtOAc (50 mL) and filtered over Celite. The filtrate was concentrated and the residue was chromatographed over silica gel (Isco CombiFlash Companion unit, 24 g Redisep column, 0% to 15% EtOAc in hexanes) to provide tert-butyl 4-(2-fluoro-6-(trifluoromethyl)phenyl)piperidine-1-carboxylate (22) as a white solid (0.219 g, 45%): 1H NMR (300 MHz, DMSO-d6) δ 7.62-7.48 (m, 3H), 4.15-3.94 (m, 1H), 3.10-2.94 (m, 2H), 2.93-2.67 (m, 2H), 2.00-1.79 (m, 2H), 1.67-1.55 (m, 2H), 1.42 (s, 9H).

1. filtrationfiltered over Celite
2. concentrationThe filtrate was concentrated
3. customthe residue was chromatographed over silica gel (Isco CombiFlash Companion unit, 24 g Redisep column, 0% to 15% EtOAc in hexanes)