二氟乙酰乙酸乙酯的合成

Synthesis of Ethyl 4,4-Difluoroacetoacetate

二氟乙酸乙酯和乙酸乙酯(摩尔比为1∶3)在乙醇钠催化下进行克莱森酯缩合反应,得到二氟乙酰乙酸乙酯。反应在50℃下进行4h,以过量的乙酸乙酯和反应生成的乙醇共沸除掉乙醇,使反应进行完全。除掉溶剂后减压蒸馏得纯度大于99%的产品,产品收率68.14%。

Ethyl 4,4-difluoroacetoacetate was synthesized from ethyl acetate and 4,4-difluoroacetoacetate（mole ratio 3∶1） with sodium ethylate.The reaction was carried at 50℃ for 4 hours.Ethanol from the reaction was removed by distilling the azeotropic of ethyl acetate and ethanol to complete the reaction.The yield was 68.14% with purity no less than 99%.