反应详情

11.4 g of 2-hydroxy-4-methoxybenzophenone were dissolved in 30 ml of dimethyl phthalate at 80° C., and 3.5 ml of chlorosulfonic acid were added dropwise at this temperature. Stirring was carried out for a further 4 hours at 80° C., the mixture was cooled to room temperature and 25 ml of ether were added to the solution. The precipitate was filtered off under suction, washed with ether and hexane and dried under reduced pressure at 30° C. 10 g of 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid of melting point 112°-114° C. were obtained (water content 7.7%).

1. filtrationThe precipitate was filtered off under suction
2. washwashed with ether and hexane
3. customdried under reduced pressure at 30° C