反应详情

4,4'-Dimethoxybenzil (10 g), 90 ml glacial acetic acid and 160 ml 48% HBr were heated at reflux for 4 hours. The reaction mixture was poured into ice and the product collected by filtration. Dissolution of the solid into 10% aqueous sodium hydroxide, extraction with diethyl ether and acidification of the aqueous layer gave 4,4'-dihydroxybenzil which was recrystallized from 75% ethanol. Yield 7.5 g (84%). 1H NMR (acetone-d6) δ9.53 (s,2H, OH), 7.81, 6.98 (m, 8H, aromatic).

1. temperatureat reflux for 4 hours
2. additionThe reaction mixture was poured into ice
3. filtrationthe product collected by filtration
4. dissolutionDissolution of the solid
5. extractioninto 10% aqueous sodium hydroxide, extraction with diethyl ether and acidification of the aqueous layer