Synthetic method for 2-methyl-3-trifluoromethyl phenylamine

Abstract

The invention discloses a synthetic method for 2-methyl-3-trifluoromethyl phenylamine. The method comprises the following steps: 1) preparing 3-nitro-4-methyl benzenesulfonic acid; 2) preparing 3-nitro-4-methyl-5-bromobenzenesulfonic acid; 3) preparing 2-nitro-6-bromotoluene; 4) preparing 2-nitro-6-trichloromethyl toluene; 5) preparing 2-nitro-6-trifluoromethyl toluene; 6) preparing 2-methyl-3-trifluoromethyl phenylamine, that is, adding 5% palladium-charcoal and methanol in 2-nitro-6-trifluoromethyl toluene obtained in step 5), carrying out hydrogenation reduction at a temperature of 35 DEG C and removing a catalyst so as to obtain 2-methyl-3-trifluoromethyl phenylamine. According to the invention, p-toluenesulfonic acid is used as a starting material, and therefore, disadvantages of theprior art are overcome and yield of a target product is improved.

Description

technical field [0001] The invention relates to poultry medicine, which is a method for synthesizing the intermediate 2-methyl-3-trifluoromethylaniline of special medicine for animals. Background technique [0002] 2-Methyl-3-trifluoromethylaniline is an intermediate of flunixin meglumine, which is one of the few approved non-steroidal drugs for animals, mainly through the inhibition of epoxy It reduces the production of inflammatory mediators such as prostaglandins and exerts antipyretic, anti-inflammatory and analgesic effects. The synthetic routes of the drug all adopt 2-methyl-3-trifluoromethylaniline as an intermediate and 2-chloronicotinic acid or ethyl 2-chloronicotinic acid to undergo nucleophilic substitution on the pyridine ring to obtain flunixin, and then Flunixin and meglumine undergo an acid-base salification reaction to obtain flunixin meglumine. Due to the unique position of the substituents on the benzene ring of 2-methyl-3-trifluoromethylaniline, the syn...

AI Technical Summary

Problems solved by technology

Due to the unique position of the substituents on the benzene ring of 2-methyl-3-trifluoromethylaniline, the synthesis process is more complicated and the production cost is higher, so 2-methyl-3-trifluoromethylaniline becomes a restricted fluorine Main Factors of Nisin Meglumine Production Cost

And U.S. Patent No. 4,172,095 discloses a method for synthesizing 2-methyl-trifluoromethylaniline: take 3-trifluoromethylaniline as raw material, first condense with dimethyl sulfoxide, then rearrange, and reduce to obtain 2 -Methyl-3-trifluoromethylaniline, the main disadvantage of this method is that there is no positi...