Novel synthesis process of high-purity pesticide intermediate

Abstract

The invention discloses a novel synthesis process of a chlorimuron-ethyl intermediate, i.e., high-purity 2-amino-4-chlorin-6-methoxypyrimidine (chloropyrimidine for short). The process comprises the following steps of: adding 2-amino-4,6-dichloropyrimidine (dichloropyrimidine for short) into a mixed solvent; raising the temperature and dropwise adding sodium methoxide; after reacting, adding a decolorizing agent; filtering, cooling, crystalizing and washing to obtain a high-purity target; and after a mixed mother solution is used for sufficient batches, performing distillation treatment. Due to the adoption of the process, the yield and total yield level of a high-purity product are increased, and the production difficulty is lowered greatly; and a high-end chlorimuron-ethyl product synthesized by using the high-purity chloropyrimidine intermediate produced with the process has strong competitive strength in domestic and international markets.

Description

Technical field: [0001] The invention relates to a production process of a chlorimuron-methyl intermediate, in particular to a new process for the preparation of high-purity 2-amino-4-chloro-6-methoxypyrimidine. Background technique: [0002] Chlorimuron-methyl is a selective pre-emergence and post-emergence herbicide, which can be absorbed by plant roots, stems, and leaves, conducts up and down in the plant body, and exerts herbicidal effect on vigorously growing meristem cells. It is mainly used in soybean fields Control broadleaf weeds. [0003] At present, the process commonly used in China is to react 2-amino-4,6-dichloropyrimidine with sodium methoxide in a methanol system. After the reaction is completed, the methanol is distilled, and then crystallized with water to obtain khaki powder particles with a content of 95-97%. That is a crude chloropyrimidine. Then use toluene or ethylene dichloride as a solvent, decolorize activated carbon, and then cool down to crystal...

AI Technical Summary

Problems solved by technology

[0005] The method provided by the present invention then uses the mixed system instead of the traditional methanol single system, adopts a crystallization method to obtain high-purity 2-amino-4-chloro-6-methoxypyrimidine products, and improves the yield and overall yield of high-purity products. Yield, overcome the disadvantages of low yield, heavy pollution and difficult production in the traditional method, provide a new production process, and achieve better economic results