反应详情

2-Acetyl-7-methoxybenzofuran (5 g) (0.0263 mole) was added to chlorosulfonic acid (18.4 g) (0.158 mole) at -15° C. in portionwise (each 0.5 g) for 30 min. After stirring the reaction mixture at -10° to -5° C. for 1 hour, the resultant was gradually added dropwise to ice. The solution was extracted with ethyl acetate, washed with water and dried, followed by distilling away ethyl acetate under reduced pressure to give 5.8 g of crude 2-acetyl-4-chlorosulfonyl-7-methoxybenzofuran.

1. additionthe resultant was gradually added dropwise to ice
2. extractionThe solution was extracted with ethyl acetate
3. washwashed with water
4. customdried
5. distillationby distilling away ethyl acetate under reduced pressure