反应详情

5 g of 3-(p-dimethylaminophenyl)-phthalide was dispersed into 20 cc of 10% aqueous solution of sodium hydroxide and the resultant mixture was heated at 90° C. for one hour with stirring to obtain a homogeneous solution. After cooling the solution to room temperature, 50 cc of 6% aqueous solution of potassium permanganate was dropped into the solution for about one hour. Then the solution was heated at 60° C. for one hour with stirring and cooled to precipitate manganese dioxide. The manganese dioxide was filtered off. Hydrochloric acid was added into the filtrate until the pH of the filtrate became 6.0 to precipitate pale yellow solid. The solid was filtered and then dried. The yield was 1.4 g. Recrystallization from a diluted aqueous solution of acetic acid gave benzophenone derivative represented by the following formula in the form of pale yellow crystals whose m.p. was 203° C. ##STR59##

1. customto obtain a homogeneous solution
2. temperatureThen the solution was heated at 60° C. for one hour
3. stirringwith stirring
4. temperaturecooled
5. customto precipitate manganese dioxide
6. filtrationThe manganese dioxide was filtered off
7. additionHydrochloric acid was added into the filtrate until the pH of the filtrate
8. customto precipitate pale yellow solid
9. filtrationThe solid was filtered
10. customdried
11. customRecrystallization from a diluted aqueous solution of acetic acid