反应详情

To a mixture of 2.43 moles (324 g.) of aluminum chloride in 648 ml. of dichloromethane is added a solution of 0.88 mole (274 g.) of 1,4-bis(2,2,2-trifluoroethoxy)benzene and 0.97 mole (92 ml.) of acetic anhydride in 880 ml. of dichloromethane over a 3 hour period while maintaining the temperature at above 0° C. The reaction mixture is then heated to its reflux temperature and stirred at reflux for 5 hours. The progress of the reaction is followed using thin-layer chromatography. The reaction mixture is placed in an ice bath and ice and 10 percent hydrochloric acid are added slowly to decompose the aluminum chloride complex. The temperature of the reaction mixture is not allowed to exceed 25° C. The organic phase is separated and washed once with 2 liters of 10 percent hydrochloric acid and then with 2 liters of water. The combined aqueous phase is extracted with several liters of dichloromethane. The organic phase is dried over magnesium sulfate, then evaporated to provide a moist residue. Hexane is added to the residue and the resulting solid is collected by filtration and washed with hexane. Upon drying, 250 g. of light yellow crystalline 2,5-bis(2,2,2-trifluoroethoxy)acetophenone is obtained. The yield is 90 percent, the m.p. is 84° to 86° C.

1. temperatureThe reaction mixture is then heated to its
2. temperaturereflux temperature
3. temperatureat reflux for 5 hours
4. customThe reaction mixture is placed in an ice bath
5. customto exceed 25° C
6. customThe organic phase is separated
7. washwashed once with 2 liters of 10 percent hydrochloric acid
8. extractionThe combined aqueous phase is extracted with several liters of dichloromethane
9. dry with materialThe organic phase is dried over magnesium sulfate
10. customevaporated
11. customto provide a moist residue
12. filtrationthe resulting solid is collected by filtration
13. washwashed with hexane
14. customUpon drying