Novel pymetrozine crude drug synthesis process

Abstract

The invention discloses a novel pymetrozine crude drug synthesis process. The novel pymetrozine crude drug synthesis process comprises the following steps: synthesizing acethydrazide: enabling ethyl acetate and hydrazine hydrate to have an acylation reaction to produce acethydrazide; synthesizing 2-methyl-1,3,4-oxadiazole-5(4H)-ketone: enabling the acethydrazide and trichloromethyl carbonate to have a photochemical reaction to produce 2-methyl-1,3,4-oxadiazole-5(4H)-ketone; synthesizing acetamido triazinone (L4): enabling the 2-methyl-1,3,4-oxadiazole-5(4H)-ketone and cholroacetone to have a condensation reaction to produce a condensation compound, enabling the condensation compound and the hydrazine hydrate to react to produce the acetamido triazinone; synthesizing 3-bromonicotinaldehyde: conducting catalytic hydrogenation on 3-cyanopyridine to produce the 3-bromonicotinaldehyde; synthesizing pymetrozine: enabling the acetamido triazinone to react with methyl alcohol and hydrochloric acid to produce N-amino-4-methyl-2,3,6-triazinone, and enabling the N-amino-4-methyl-2,3,6-triazinone and the 3-bromonicotinaldehyde to condensate to produce pymetrozine. The novel pymetrozine crude drug synthesis process has the advantages that the reaction yield is high, the production efficiency is greatly improved, the prices of reaction materials are moderate, and the materials do not pollute the environment.

Description

technical field [0001] The invention relates to the field of pesticides, in particular to a new process for synthesizing the original drug of pymetrozine. Background technique [0002] Pymetrozine, also known as pyrazinone, is a pyridine heterocyclic insecticide with a new structure. It was discovered by Swiss Syngenta Crop Protection Co., Ltd. in 1988 and developed for aphids, powders on various crops. Control of lice, leafhoppers and various planthoppers. Due to its unique insecticidal mechanism, once pymetrozine appeared, it became a hot spot in the production and development of pesticides at home and abroad. [0003] The synthesis of pymetrozine is obtained by the reaction of aminotriazone and nicotinic aldehyde. The commonly used synthetic route is the reaction of aminotriazone and nicotinic aldehyde precursor Schiff base. The raw materials used in this synthetic route are mainly Two synthetic pathways, one is prepared by condensing 3-aminomethylpyridine as a starting...

AI Technical Summary

Problems solved by technology

The former, the market price of 3-aminomethylpyridine is very high, while the latter needs to use expensive rhodium as catalyst, which does not have practical development value