Process for producing trifluoro benzene acetic acid

Abstract

The invention provides a method for preparing trifluorobenzene acetic acid. The method comprises: trifluorobromobenzene is used as raw material and magnesium undergo Grignard reaction to generate a Grignard reagent; in the presence of cobalt salt catalyst, the Grignard reagent reacts with bromoacetic acid ester to form trifluorobenzene acetate; under conditions of acid or alkali, the trifluorobenzene acetate is hydrolyzed to form a coarse product of the trifluorobenzene acetic acid; and the coarse product is post-treated to form the trifluorobenzene acetic acid with the concentration of more than 99 percent. The method has the advantages of easily bought raw material, low cost, mild reaction condition, simple operation, environmental protection and easy realization of industrialization, and the product prepared by the method has stable quality, and is easy in mass industrialized production.

Description

technical field [0001] The present invention relates to a kind of preparation method of trifluorophenylacetic acid Background technique [0002] Trifluorophenylacetic acid is an important intermediate that plays an irreplaceable role in the synthesis of pharmaceuticals and electronic materials. U.S. Patent 6,395,921 reports a reaction between trifluorobromobenzene and malonic acid diester under the action of alkali, decarboxylation and hydrolysis to obtain trifluorophenylacetic acid. This method is not suitable for large-scale industrial production. U.S. Patent No. 6,870, reported a kind of use 2,4,5-trifluorobromobenzene to make Grignard reagent and bromide reaction in 067, obtain 2,4,5-trifluorophenylacetic acid in oxidation, oxidizing agent in this method Raw materials such as sodium periodate and catalyst ruthenium trichloride are relatively expensive, and more side reactions will occur when the Grignard reagent reacts with vinyl bromide, and the product quality is diff...

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Problems solved by technology

U.S. Patent No. 6,870, reported a kind of use 2,4,5-trifluorobromobenzene to make Grignard reagent and bromide reaction in 067, obtain 2,4,5-trifluorophenylacetic acid in oxidation, oxidizing agent in this method Raw materials such as sodium periodate and catalyst ruthenium trichloride are relatively expensive, and there will be more side reactions when the Grignard reagent reacts with vinyl bromide, and the product quality is difficult to control

Chinese patent 1,003,471,42C has reported a method to obtain 2,4,5-trifluorophenylacetic acid through chloromethylation, cyanation and hydrolysis reaction with 1,2,4-trifluorobenzene, this method will CN (-) waste water, polluting the environment

European patent EP148,430, 4A1 reported a kind of reaction with bromobenzene and Mg to generate Grignard reagent, and then with ZnCl 2 Reaction generates Zn reagent, then reacts with bromoacetate, and then obtains the method of phenylacetic acid through hydrolysis, needs Grignard reagent and ZnCl in this method 2 Carry out metal exchange reaction, increase reaction step, cause total yield to reduce, industrialization cost is high, and will use at least equimolar ZnCl 2 , which increases the difficulty of post-treatment and creates more pollutants

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