反应详情

In 3 liters of dry ethanol, 75 g of 4,4'-bismethoxybenzoin and 21 g of sodium borohydride were refluxed for 2 hours. After adding 250 ml of concentrated hydrochloric acid to the reaction mixture, the resulting mixture was poured into 1300 ml of ice water, followed by filtration of deposited crystals. After recrystallized from 95% ethanol, there was obtained 57 g of 1,2-di(p-methoxyphenyl)ethane-1,2-diol, which was then added to 570 ml of 80% acetic acid and stirred at 90° C. for 50 minutes. Then, the reaction mixture was poured into 4 liters of ice water and deposited crystals were filtered. After drying, the crystals were recrystallized from isopropyl ether to give 40 g of Compound (e) in 69% yield.

1. filtrationfollowed by filtration of deposited crystals
2. customAfter recrystallized from 95% ethanol