Study On The Synthetic Process Of The 5-(2-Chloro-4-(Trifluoromethyl) Phenoxy)-2-Nitro-Benzoic Acid

5-(2-Chloro-4-(trifluoromethyl)-phenoxy)-2-nitro-benzoic acid, also known as acifluorfen, is a fluorine-containing diphenyl ether herbicide, contacting selective herbicide after bud, which is used for the control of annual broadleaf weeds and soybeans, peanuts and other weeds. 5-(2-Chloro-4-trifluoromethylphenoxy)-2-nitrobenzoic acid is an important intermediate for the preparation of pesticides Lactofenac and Fomesafen. So the market demand for 5-(2-Chloro-4-(trifluoromethyl)-phenoxy)-2-nitro-benzoic acid is very large.The company's existing production process is from m-hydroxybenzoic acid salt,etherification and a series of reactions to the original drug. This paper studied the preparation of high content of Acifluorfen. The methyl phenol is as the main raw material, through salt formation, etherification, oxidation, to preparation of 3-(2- chlorine-4- three fluorine methyl phenoxy) benzoic acid, then through nitration of 5-(2-chloro-4-(trifluoromethyl)-phenoxy)-2-nitro-benzoic acid. Through the experimental comparison could get higher content of Acifluorfene, lower waste, and through the scale up experiments, and calculate the cost, the cost of production could be significantly reduce compared with the original process.The traditional fluorine sulfadoxine production process is the use of m-hydroxy benzoic acid, 3,4-dichlorotrifluorotoluene and methyl sulfonamide as the main raw material, through salt, condensation, nitration, amidation reaction to get the target product, domestic production Enterprises mainly use above technology, which is high production costs, resulting in more waste, a greater impact on the environment.Here, we were first synthesized the 3-(2-chloro-4-trifluoromethyl-phenoxy) toluene by using m-methylphenol and potassium hydroxide, followed by the addition of3,4-dichlorotrifluorotoluene. Next, sodium bromide, azobisisobutyronitrile, tetrabutylammonium bromide and acetic acid were added to the chlorobenzene system, and then oxidizing with oxygen to give 5-(2-chloro-4-(trifluoromethyl) phenoxy)-2-nitro-benzoic acid.3-(2-chlorine-4-trifluormethyl phenoxy) benzoic acid carried out nitrification by using copper nitrate in chloroform system, and high content of 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitro-benzoic acid was obtained.In this paper, m-methylphenol was used as the starting material, the final product,fomesafen, was obtained by salt formation, etherification, oxidation. The preparation of intermediates in each step was studied. By adjusting the experimental parameters and optimizing the experimental conditions, the reaction process was relatively simple, and the target product was synthesized finally.