Method for synthesizing and purifying fipronil

Abstract

The invention relates to a preparation method of an efficient insecticide-fipronil, in particular to a method for synthesizing and purifying fipronil, in which CF3SO2Na and 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoro-methylphenyl)pyrazol are adopted. The method is characterized in that CF3SO2Na reacts with an appropriate reaction reagent and then fully reacts with 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl)pyrazol to obtain a coarse product of the compound 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl)-4-trifluoromethyl sulfinyl pyrazol and then the coarse product is purified to obtain fipronil with content of 97.5%. The whole method is easy in raw material acquisition, simple and convenient in process conditions and excellent in product quality.

Description

technical field [0001] What the present invention relates to is the preparation method of high-efficiency insecticide fipronil, specifically adopts CF 3 SO 2 Synthesis of Cl and 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole and method for purifying fipronil. Background technique [0002] Fipronil is a high-efficiency insecticide first developed by the French Rhone-Planck company, chemical name: 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylbenzene base)-4-trifluoromethylsulfinylpyrazole, fipronil interferes with the chloride ion channel through the chloride channel regulated by GABA, destroys the activity of normal central nervous system and causes individual die. Due to this unique effect, fipronil has remarkable characteristics different from conventional insecticides. At present, there are mainly three routes for the preparation of fipronil: route 1 is composed of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl) pyrazole and trifluorometh...

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Problems solved by technology

At present, there are mainly three routes for the preparation of fipronil: route 1 is composed of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl) pyrazole and trifluoromethylsulfide Haloalkane reaction, the introduction of trifluoromethylthio, and then oxidized by m-chloroperoxybenzoic acid to obtain 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)- 4-trifluoromethylsulfinylpyrazole, the disadvantage is that the toxicity of trifluoromethylthiohaloalkane is extremely high, and the operation process is more difficult; route 2 is made of 5-amino-3-cyano-1-(2,6-di Chloro-4-trifluoromethylphenyl)pyrazole first prepares disulfides, and oxidizes with alkyl halides to obtain 5-amino-3-cyano-1-(2,6-dichloro- 4-trifluoromethylphenyl)-4-trifluoromethylsulfinylpyrazole, the disadvantage is that the production cost is too high; Route 3 is made of 5-amino-3-cyano-1-(2,6-di One-step synthesis of chloro-4-trifluoromethylphenyl)pyrazole and sulfinyl substituents to give 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl )-4-trifluoromethylsulfinylpyrazole, the deficiency is that the yield is not high

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