tert-butyl 4-(2-chloro-3-fluorophenyl)-5,6-dihydropyridine-1(2H)-carboxylate → Tert-butyl-4-(2-chloro-3-fluorophenyl)piperidine-1 carboxylate

Participants

Reaction Steps

A mixture of tert-butyl 4-(2-chloro-3-fluorophenyl)-5,6-dihydropyridine-1(2H)-carboxylate (12, 0.488 g, 1.41 mmol) and PtO2 (0.109 g, 0.48 mmol) in EtOAc (15 mL) was stirred at ambient temperature for 18 h under a balloon of H2. The mixture was filtered over Celite, and the filtrate was concentrated under reduced pressure and dissolved in CH2Cl2 (4 mL). To this solution was added HCl (2 N in Et2O, 4.0 mL) and the resulting mixture stirred at ambient temperature for 20 min. The resulting suspension was diluted with Et2O (20 mL) and the solids were collected by filtration to provide tert-butyl-4-(2-chloro-3-fluorophenyl)piperidine-1 carboxylate (13) as a clear semi-solid (0.471 g, 95%): 1H NMR (300 MHz, DMSO-d6) δ 7.43-7.19 (m, 3H), 4.17-4.01 (m, 2H), 3.20-3.03 (m, 1H), 2.95-2.68 (m, 2H), 1.79-1.65 (m, 2H), 1.58-1.45 (m, 2H), 1.41 (s, 9H).

Provenance & Evidence