Dichloromethane → HCID 66738924, compound

Participants

Reaction Conditions

Reaction Steps

While the internal temperature of the reactor containing 2.622 kg (5.20 mol) of 1-propoxy-2,3,4-tribenzoyl-L-arabinopyranose was maintained at 0-20° C., 4.21 kg of a 30-33% hydrogen bromide/acetic acid solution was added dropwise thereto, and the mixture was stirred at room temperature for 6 hours. After completion of the reaction, 1.296 liters of dichloromethane was added to the reaction solution, which was then stirred for 30 minutes. The stirred solution was added dropwise to a reactor containing 4.162 liters of purified water and stirred for 30 minutes. Then, the stirred solution was separated into layers. The water layer was back-extracted with 1.296 liters of dichloromethane. The oil layer was washed two times with 0.195 kg of aqueous saturated sodium chloride solution and one time with 0.248 kg of aqueous saturated sodium bicarbonate solution, and then dried with sodium sulfate, and the solvent was removed by concentration. To the concentrated residue, 1.30 liters of dichloromethane was added, and the solution was stirred for 2-3 hours. 6.50 liters of hexane was added to the stirred solution, which was then cooled to a temperature of 0-5° C., stirred for 3-4 hours, and filtered. The filtered solids were washed with 2.76 liters of hexane and dried in a vacuum, thus obtaining 2.185 kg (80% yield) of 1-bromo-2,3,4-tribenzoyl-L-arabinopyranose. 1H NMR (CDCl3): δ 8.20-7.90 (dd, 4H), 7.90-7.80 (d, 2H), 7.70-7.20 (m, 9H), 6.93 (d, 1H), 5.97 (dd, 1H), 5.82 (m, 1H), 5.70 (dd, 1H), 4.50 (d, 1H), 4.25 (d, 1H).

Provenance & Evidence