反应详情

To a stirred solution of 5-(5-chloro-2-methoxyphenyl)imidazo[1,2-a]pyridine (1.82 g, 7.03 mmol) in dichloromethane (30 mL) at −78° C. was added boron tribromide (1.0 mL, 10.6 mmol). The mixture was allowed to warm to ambient temperature and stirred for 4 h and cooled to 0° C. The reaction mixture was cautiously diluted with water and the pH was adjusted to >7 by the addition of 2 M aqueous sodium carbonate, causing a precipitate to be deposited. The solid was collected by filtration and washed sequentially with water, dichloromethane and diethyl ether to afford 4-chloro-2-(imidazo[1,2-a]pyridin-5-yl)phenol as a colorless solid in 73% yield (1.26 g): 1H NMR (300 MHz, DMSO-d6) δ10.41 (s, 1H), 7.72-7.55 (m, 2H), 7.55-7.28 (m, 4H), 7.06 (d, J=8.4 Hz, 1H), 6.91 (d, J=6.9 Hz, 1H); MS (ES+) m/z 245.0 (M+1), 247.0 (M+1).

1. temperaturecooled to 0° C
2. filtrationThe solid was collected by filtration
3. washwashed sequentially with water, dichloromethane and diethyl ether