Method for preparing picolinafen

Abstract

The invention discloses a method for preparing picolinafen, and belongs to the field of pesticide original medicine technology. The method comprises the following steps that (1) 2-chlorine-6-nitrapyrin serves as a raw material, and acid catalysis hydrolysis is carried out to synthesize 2-chlorine-6-pyridine carboxylic acid; (2) under conditions of alkali 1, catalyst and organic solvent 1, etherification reaction is carried out on 2-chlorine-6-pyridine carboxylic acid and m-trifluoromethylphenol to obtain 2-(3-trifluoromethylphenoxy pendant)-6-picolinic acid; (3) the 2-(3-trifluoromethylphenoxypendant)-6-picolinic acid and di(trichloromethyl) dimethyl carboxylate are reacted in alkali 2 and organic solvent 2 to synthesize intermediate 2-(3-trifluoromethylphenoxy pendant)-6-pyridinecarbonylchloride; (4) the intermediate 2-(3-trifluoromethylphenoxy pendant)-6-pyridinecarbonyl chloride and 4-fluoroaniline are reacted in alkali 3 and organic solvent 2 to prepare the picolinafen. The method for preparing the picolinafen has the advantages that the content of the prepared picolinafen product is 98.1%, the yield of the prepared picolinafen product is 83%, synthesis conditions are mild and safe, the operation process is controlled easily, aftertreatment is simple and convenient, the wastewater quantity is less, and the method is a green synthetic method for preparing the picolinafen.

Description

technical field [0001] The present invention relates to a preparation method of diflupyramid, which specifically uses 2-chloro-6-trichloromethylpyridine as a raw material, and prepares flupyramid through four steps of hydrolysis, etherification, acyl chloride and amidation The invention relates to an amine technical substance, which belongs to the technical field of herbicide technical substances. Background technique [0002] Picolinafen is a pyridinamide herbicide developed by BASF, which was launched in 2002. Mainly used in corn, soybean and wheat fields to control a variety of annual grass weeds and some broad-leaved weeds. This variety is a selective contact and residual herbicide, and its mode of action is to hinder the biosynthesis of carotenoids through the inhibition of phytoene dehydrogenase. Compared with other pyridinamide herbicides, flupifenamide has the characteristics of high herbicidal activity, long duration, not easy to decompose, and safe to crops. Sin...

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Problems solved by technology

[0003] BASF patent US4504665 has reported the synthetic method of flufenamide, methyl phenol reacts to synthesize ether, and then reacts with p-fluoroaniline to synthesize flufenamide. The route change has the advantages of high yield and easy post-synthesis treatment, but the preparation In the case of 2-(3-trifluoromethylphenoxy)-6-pyridinecarbonyl chloride, thionyl chloride is used as the chlorinating agent, and sulfur dioxide and hydrogen chloride are produced after the post-treatment. The tail gas is difficult to effectively separate and recycle, and has an impact on the environment. Very large, high requirements for equipment, increased cost

[0004] At present, there is no research report on the synthesis process of flupifenamide in China, so its research has important practical significance

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