Synthetic method of imidacloprid

Abstract

The invention provides a synthetic method of imidacloprid, which comprises the synthetic steps of (1) sequentially adding an amine substance, 2-chlorine-5-chlorine picoline and a solvent into a reactor, conducting heating reflux for 2h, cooling, obtaining a catalyst solution, (2) sequentially adding a solvent, 2-nitryl imidogen imidazolidine and 1 / 5 alkali metal hydroxide into the catalyst solution, stirring, heating to 45 DEG C for heat preservation; (3) dropwise adding a solvent solution of 2-chlorine-5-chlorine picoline into reaction liquid for 30min each time and for four times totally after the heat preservation is over, adding 1 / 5 alkali metal hydroxide into the reaction liquid after dropwise adding the solvent solution each time, conducting heat preservation reaction for 1-2h after finishing the adding, and (4) conducting water washing for three times after the reaction is over, distilling the solvent out, crystallizing at 5 DEG C below zero, conducting suction filtration, drying, and obtaining a crude product of imidacloprid. According to the synthetic method, the reaction time is short; by-products are few; the purity of the crude product of imidacloprid reaches 98%; and a yield reaches 95.3%.

Description

technical field [0001] The invention relates to the field of insecticides, in particular to a method for synthesizing the insecticide imidacloprid. Background technique [0002] As an insecticide that works by blocking the nervous system of insects, imidacloprid has three functions of systemic conductivity, contact killing and gastric toxicity. It is known as one of the three major insecticides across the century. Prospects for Traditional Highly Toxic Pesticides. [0003] At present, the traditional imidacloprid production process at home and abroad has gradually screened out solvents and alkalis that are better for the synthesis of imidacloprid, but the specific synthesis method is still simply mixing various raw materials with solvents and catalysts and then directly reacting, and there is a common reaction cycle. long, high energy consumption, excessive by-products, and low yield. [0004] Patent CN101011057 uses 2-chloro-5-chloromethylpyridine and 2-nitroiminoimidazo...

AI Technical Summary

Problems solved by technology

[0003] At present, the traditional imidacloprid production process at home and abroad has gradually screened out solvents and alkalis that are better for the synthesis of imidacloprid, but the specific synthesis method is still simply mixing various raw materials with solvents and catalysts and then directly reacting, and there is a common reaction cycle. long time, high energy consumption, excessive by-products, and low yield

[0004] Patent CN101011057 uses 2-chloro-5-chloromethylpyridine and 2-nitroiminoimidazolidine as raw materials, selects a high boiling point protic solvent, and reacts in the presence of alkali metal hydroxide, and the yield is improved , but because the reaction is a two-phase reaction, there are still problems of long reaction time and low product purity

Patent CN201010197424 uses quaternary ammonium salts as phase transfer catalysts to increase the reaction rate and reduce the reaction conditions, but there are many by-products and the product purity is still not good