Halogen-Exchange Fluorination of Chlorinated Benzaldehydes and Diphenyl Ketones Promoted by Microwave
Fluorinated benzaldehydes and diphenyl ketones were synthesized via halogen-exchange fluorination in less polar aprotic solvents in the presence of phase transfer catalyst, with or without the irradiation of microwave. The products were easily obtained with significantly enhanced yield and selectivity with microwave irradiation when compared with conventional heating. The yield of products was in the range of 52.0%~94.2%, and the reaction time can be shortened by more than 90% at most in comparison with common heating. In addition, special microwave effect is obvious when reaction was carried in medium polar aprotic solvents. Therefore, more aprotic solvents can be used in halogen-exchange fluorination under the irradiation of microwave.
Z. Y. Liang and C. X. Lü, "Halogen-Exchange Fluorination of Chlorinated Benzaldehydes and Diphenyl Ketones Promoted by Microwave", Advanced Materials Research, Vol. 266, pp. 292-295, 2011