反应详情

16.7 g (0.1 mole) of 2,3-dichloromaleic anhydride is dissolved in 100 ml of dioxane, and a solution of 15.9 g (0.1 mole) of o-difluoromethoxyaniline in 30 ml of dioxane is added dropwise to it at room temperature over 20 minutes with stirring. Thereafter, the resulting solution is stirred at 70°-80° C. for 2 hours and the dioxane is then distilled off under a reduced pressure. Water is added to the residue to precipitate crystals. The precipitated crystals are filtered off and recrystallized from ethanol to give 27.7 g (yield: 90%) of 2,3-dichloro-N-(o-difluoromethoxyphenyl)maleimide melting at 103.5°-104° C. in the form of light yellow crystals.

1. stirringThereafter, the resulting solution is stirred at 70°-80° C. for 2 hours
2. distillationthe dioxane is then distilled off under a reduced pressure
3. additionWater is added to the residue
4. customto precipitate crystals
5. filtrationThe precipitated crystals are filtered off
6. customrecrystallized from ethanol