A kind of synthetic method of flunixin

Abstract

The invention belongs to the technical field of chemical synthesis and particularly relates to a method for synthesizing flunixin. The method comprises that 2-chloronicotinic acid and 2-methyl-3-trifluoromethylaniline undergo a reaction under the catalysis of a perfluorosulfonic resin to produce flunixin. The perfluorosulfonic resin as a catalyst can react fast and realize a high yield of 97%.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a method for synthesizing flunixin. Background technique [0002] The chemical formula of flunixin: C 14 h 13 f 3 N 2 , the chemical name is 2-[[2-methyl-3-(trifluoromethyl)phenyl]amino]-3-pyridinecarboxylic acid, [0003] Structural formula: . [0004] Flunixin is the key raw material for preparing flunixin meglumine, and it is mainly prepared as flunixin meglumine for use. Flunixin meglumine (flunixin meglumine) is a new type of non-steroidal animal-specific antipyretic and analgesic drugs, which belongs to the niacin derivatives and is an inhibitor of cyclooxygenase. Developed by Schering-Plough in the 1990s (trade name: Banamine), it has been widely used in many countries such as the United States, France, Switzerland, Germany, and the United Kingdom. Flunixin meglumine has antipyretic, anti-inflammatory and analgesic effects. It can significan...

AI Technical Summary

Problems solved by technology

This method uses xylene as a high temperature or highly toxic solvent, and the reaction requirements are relatively high, while the yield is low, and post-processing is difficult in actual production.

2. According to US5484931, 2-chloronicotinic acid and 2-methyl-3-trifluoromethylaniline were used as raw materials, and p-toluenesulfonic acid was catalytically refluxed for more than 24 hours to obtain flunixin with a yield of 83%. The main raw materials in this method 2-Methyl-3-trifluoromethylaniline is used in excess, the reaction time is long, the post-treatment is complicated, the yield is not high, the overall production cost is high, and the economy is poor

3. Heterocycles, 38(10), 1994, 2243-2246 reported that 2-methyl-3-trifluoromethylaniline and 2-chloronicotinic acid ethyl ester were used as raw materials, ethylene glycol was used as solvent, and after 6 hours of reaction at 165°C The solvent is evaporated and hydrolyzed to obtain flunixin with a total yield of 77.4%. In this method, the reaction temperature is high, the efficiency of distilling off the high boiling point solvent ethylene glycol is low, the hydrolysis reaction and subsequent steps are complicated, the yield is low, and the economy is poor

The yield of this method is about 90%, which is suitable for industrial production, but the recovery of the solvent polyethylene glycol or ethylene glycol used in this method will relatively increase the production cost, and the treatment of copper-containing wastewater will also increase the cost of anhydrous treatment.

Images