| This paper studies on the synthesis of 2,3,4,5-tetrafluoro benzoic acid, which is an important curatorial intermediate. Tetrafluoro benzoic acid was respectively prepared from the raw stuff tetrachloride phthalic anhydride through imide(include imidization, fluorination, hydrolyzation and decarboxylation 4 steps)and acyl chloride(include hydrolyzation, acyl chlorination, fluorination, hydrolyzation and decarboxylation 5 steps ) two different routes.The imide route was employed to synthesis tetrafluoro benzoic acid. Tetrachloride phthalic anhydride was reacted with aniline under the catalysis of hexadecyltrimethyl amminobromide with acetic acid as solvent to form N-phenyl tetrachloride phthalimide. With potassium fluoride as the fluridizer, N-phenyl tetrafluoride phthalimide was obtained from N-phenyl imine tetrachloride phthalimide under the catalysis of calixarene A with cyclobutylsulfone as solvent. With sulfuric acid as solvent and sodium dodecylbenzene sulfonate as catalyst, we prepared tetrafluoride phthalic acid. And tetrafluoride phthalic acid was further decarboxylated in the solvent of tri-n-butyl amine. Then tetrafluoro benzoic acid was obtained. The totle yield was 64.2ï¼….Samely in the acyl chloride route, tetrachloride phthalic anhydride was added into the solvent of sodium hydroxide and then into the hydrochloric acid to produce tetrachloride phthalic acid; then reacted with thiony chloride under the catalysis of DMF to form tetrachloride phthaloyl chlorideï¼›with potassium fluoride as the fluridizer, calixarene A as the catalysis, substitution fluorination was taken place in the solvent of cyclobutylsulfone to give the product from tetrachloride phthaloyl chloride and then the product was added into the solvent of potassium bicarbonate to be hydrolyzated to synthesis tetrafluoride phthalic acidï¼›and then tetrafluoro benzoic acid was finally formed in the solvent of tri-n-butyl amine by decarboxylation of tetrafluoride phthalic acid. The totle yield was 44.7%.
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