Preparation process of ethyl fluoroacetate

　　ethyl fluoroacetateIt is a volatile colorless liquid with a pungent odor. It is an important organic chemical raw material, mainly used for the synthesis of ethyl trifluoroacetoacetate, trifluoroacetyl, 2-thienyl trifluoro-fluorine and other organic fluorine compounds. It can also be used in the preparation of pesticides, pharmaceuticals, dyes, liquid crystals and chemical raw materials, and can be used as analytical reagents, solvents, catalysts, dehydration condensation agents and protective agents in the process of hydroxyl and amino trifluoroacylation. Raw materials for the preparation of organofluorine fine chemicals, pharmaceuticals and pesticides.

The preparation of ethyl fluoroacetate is obtained by esterification of fluoroacetic acid with ethanol. Because the raw material fluoroacetic acid is expensive, it is of great practical significance to improve the reaction yield.

　　ethyl fluoroacetateThe Claisen condensation with ethyl acetate yields ethyl trifluoroacetoacetate, a very useful trifluoromethyl-containing building block. Zhang Guohua et al. The condensation of ethyl acetate with ethyl fluoroacetate in the presence of sodium ethoxide is reported to give ethyl trifluoroacetoacetate in 75.9% yield.

During the preparation of ethyl fluoroacetate, the solid acid catalyst was pre-dispersed in the filler of the distillation column. An appropriate amount of fluoroacetic acid and ethanol are pre-added into the reaction kettle with a packed distillation column according to the specified ratio, and heated to reflux. When the ratio of each component in the distillation column reaches a stable level, ethanol and fluoroacetic acid are fed in predetermined ratios from the bottom and the top of the extraction section of the distillation column, respectively. The product can be collected directly at the top of the distillation column after purification, the reaction yield is more than 99%, and the product purity is more than 99.9. The reaction process adopts the continuous feeding method, and the water in the kettle is discharged regularly and quantitatively, which realizes continuous production and improves productivity. The distillation device adopts automatic control, which can accurately adjust the distillation reflux ratio.

the choice of alcohol molar ratio:

molar ratio of acid to alcoholethyl fluoroacetateThe effect of esterification rate is different. Under certain conditions of catalyst dosage and reaction time, the esterification rate of ethyl fluoroacetate gradually increased with the increase of the molar ratio of acid to alcohol. When the molar ratio of acid to alcohol is 1:1.4, the esterification rate reaches a large value of 99.2, so the molar ratio of acid to alcohol should be controlled at about 1:1.4.

choice of catalyst dosage:

The effect of the amount of catalyst on the esterification rate of ethyl fluoroacetate was different. In a certain reaction time, when the molar ratio of acid to alcohol is unchanged, the amount of catalyst increases. The esterification rate of ethyl fluoroacetate also increased gradually. When the amount of catalyst is 0.50g, the esterification rate of ethyl fluoroacetate is higher, so the amount of catalyst should be 0.50g.

The above is the preparation process of ethyl fluoroacetate. If you are interested, you can observe or operate with relevant people to learn more relevant knowledge. Of course, if you are not very skilled in operation, try not to touch chemicals.