反应详情

1.0 g of 2-(3-chloro-4-amino-5-trifluoromethyl-phenyl)-2-tert-butylaminoethanol was dissolved in 20 ml of anhydrous diethyl ether and the solution was acidified to pH=2 by adding dropwise a solution of hydrobromic acid in isopropanol with stirring. The precipitate was collected by filtration, washed with small amount of anhydrous diethyl ether, dried to give crude 2-(4-amino-3-chloro-5-trifluoromethyl-phenyl)-2-tert-butylamino-ethanol hydrobromide. The crude product was dissolved in absolute ethanol at a ratio of 1:5 w/v. Filtered and anhydrous diethyl ether was added dropwise until small amount of crystals was precipitated. Lyophilized and filtered to give 2-(4-amino-3-chloro-5-trifluoromethyl-phenyl)-2-tert-butylamino-ethanol hydrobromide. Yield 80–90%; melting point 208–210° C. (dec). 1H-NMR (DMSO-d6) δ: 1.24(9H, s), 3.79(2H, d), 4.46–4.51(1H, m), 7.72(1H, s), 7.89(1H, s).

1. filtrationThe precipitate was collected by filtration
2. washwashed with small amount of anhydrous diethyl ether
3. customdried
4. customto give crude 2-(4-amino-3-chloro-5-trifluoromethyl-phenyl)-2-tert-butylamino-ethanol hydrobromide
5. filtrationFiltered
6. additionanhydrous diethyl ether was added dropwise until small amount of crystals
7. customwas precipitated
8. filtrationLyophilized and filtered