反应详情

In accordance with example 1, 150 g of oleum is taken in a 500 ml three-necked round-bottomed flask fitted with a dry ice condenser and a bubbler (TFP inlet tube) to which 28.7 g. Br2 is then added to form a bromine-oleum mixture. The bromine-oleum mixture is stirred at room temperature for 3 hrs. The round-bottomed flask is covered with aluminum foil. TFP (18 g) is then bubbled through the mixture to form a reaction mixture. The rate of TFP addition is adjusted so that the temperature of the reaction mixture remains from about 12° C. to about 22° C. Upon addition of the TFP the bromine color is nearly gone, and the reaction mixture is stirred at room temperature for 1 hour. The reaction mixture is then poured into 300 ml of acetic acid taken in a 500 ml single-neck round-bottomed flask, stirred, and heated to 100° C. for 1 hr. This solution is cooled to room temperature and 100 ml of water is added and extracted four times with 100 ml portions of dichloromethane. (Dichloromethane forms an upper layer). Organic layers are combined and washed with saturated NaHCO3 (4×200 ml), dried over anhydrous Na2SO4 (150 g.) and evaporated (without applying vacuum) to yield acetyl bromohydrin (43.9 g.) as a clear colorless liquid. Yield=43.9 g. (99.6%), 1H NMR: (CDCl3, 300 MHz), δ ppm: 2.12(s, 3H), 4.34-4.56 (m, 3H)

1. customfitted with a dry ice condenser