Fenvalerate preparing process

Abstract

The fenvalerate preparing process with triethylamine as catalyst includes the reaction between 2-(4-chlorophenyl)-3-methyl butyric acid and dichlorosulfoxide to obtain acyl chloride; and the further reaction with the mixture of 3-phenoxy phenylaldehyde, sodium cyanide, triethylamine, water and organic solvent to obtain fenvalerate as pesticide. Compared with available technology, the present invention has the features one high yield, high product purity, low cost, mild reaction condition, simple operation, easy control of reaction, etc. and is suitable for industrial production.

Description

technical field [0001] The present invention relates to the preparation method of fenvalerate, it adopts triethylamine as catalyst, the acyl chloride obtained by reacting 2-(4-chlorophenyl)-3-methylbutanoic acid with thionyl chloride, and then reacts with 3 -One-step reaction of the mixture of phenoxybenzaldehyde, sodium cyanide, triethylamine, water and organic solvent to obtain fenvalerate pesticide. Background technique [0002] Fenvalerate [(R, S)-2-(4-chlorophenyl)-3-methylbutanoic acid-(±)-α-cyano-3-phenoxybenzyl ester] was released by Sumitomo, Japan in 1974 A high-efficiency, broad-spectrum, light-stable and low-residue pyrethroid insecticide researched and developed by a chemical industry company has special effects on the control of cotton, vegetables, fruits, tobacco, corn and potatoes. Effect can be equivalent with cypermethrin, but its synthesis process is simpler than cypermethrin, raw material is easy to solve, and production cost is low. The synthetic metho...

AI Technical Summary

Problems solved by technology

[0008] In the above-mentioned preparation method of fenvalerate, method (1) has more reaction steps, and is mainly used to prepare optically active fenvalerate; although method (2) has fewer reaction steps, many side reactions lead to reaction yield. The yield is low and the product purity is low, and the product color is dark; Method (3) is to generate cyanohydrin by 3-phenoxybenzaldehyde earlier, then use 2-(4-chlorophenyl)-3-methylbutyryl chloride to acylate , the steps are many, the total yield is low, the operation is complicated, and the more prominent shortcoming is that cyanohydrin is easy to decompose, and emits highly toxic hydrocyanic acid gas (HCN), so the reaction conditions and preservation of cyanohydrin are very harsh; method (4) The raw material α-cyano group-3-phenoxybenzyl bromide synthesis difficulty, so the cost of industrial production is bigger; Method (5) is that the first step reaction time is long, and operation is numerous and diverse, and total yield is low