反应详情

To a solution of tert-butyl 4-(2-chloro-5-fluorophenyl)-5,6-dihydropyridine-1(2H)-carboxylate (15, 0.573 g, 1.84 mmol) in CH2Cl2 (11 mL) was added HCl (2.0 N solution in Et2O, 11.0 mL) and the mixture stirred at ambient temperature for 18 h. The reaction mixture was diluted with Et2O (30 mL), and the resulting precipitate was collected by filtration to provide 4-(2-chloro-5-fluorophenyl)-1,2,3,6-tetrahydropyridine hydrochloride (16) as a white solid (0.267 g, 80%): 1H NMR (300 MHz, DMSO-d6) δ 9.15 (br s, 2H), 7.54 (dd, J=9.0, 5.4 Hz, 1H), 7.29-7.17 (m, 1H), 7.14 (dd, J=9.3, 3.0 Hz, 1H), 5.84-5.79 (m, 1H), 3.76-3.68 (m, 2H), 3.28 (t, J=5.7 Hz, 2H), 2.62-2.53 (m, 2H); ESI MS m/z 212 [M+H]+.

1. filtrationthe resulting precipitate was collected by filtration