| abstract |
The invention discloses a method for synthesizing 5-fluorosalicylic acid and belongs to the technical field of chemical synthesis. 1,4-difluorobenzene and an acetylating reagent are subjected to Friedel-Crafts acylation under the action of a catalyst to obtain 2,5-difluoroacetophenone derivatives; the obtained 2,5-difluoroacetophenone derivatives , according to the difference in the number of hydrogen atoms on the acetyl group in the structure, different degrees of chlorination reactions occur with the chlorinating reagent to obtain 2,2,2-trichloro-(2',5'-difluorophenyl) ethyl ketone ; The obtained 2,2,2-trichloro-(2',5'-difluorophenyl) ethyl ketone, under the action of alkali, obtains 2,5-difluorobenzoic acid through alkaline hydrolysis reaction; the obtained 2 ,5-difluorobenzoic acid, under the action of alkali, through defluorination hydroxylation reaction, 5-fluorosalicylic acid is obtained, the total reaction yield is more than 75%, and the product purity is more than 99%. The method has the advantages of cheap and easy-to-obtain raw materials, short synthesis steps, simple operation, mild reaction conditions, high synthesis yield, good product quality, and suitability for industrial application. |