Synthesis process of pyraclostrobin intermediate pyrazolidone

Abstract

The invention discloses a synthesis process of pyraclostrobin intermediate pyrazolidone. The process method particularly comprises the following steps: putting a p-chlorophenylhydrazine toluene solution into a dehydration kettle, performing temperature-rising azeotropy to take out toluene and water, transferring to a cyclization kettle after dehydration is completed, putting sodium methoxide solid into the cyclization kettle, adding quantitative acrylic amide, performing heat-preserving reaction at 60 to 70 DEG C for 2 to 3 hours, distilling and recovering methanol after the reaction, adding water to terminate the reaction, adding quantitative hydrochloric acid to adjust the pH value to be 5 to 6, transferring the materials to a desolvation kettle after the pH value is adjusted, evaporating and recovering the solvent toluene, transferring the materials to a crystallization kettle after desolvation is completed, cooling, crystallizing, centrifuging and performing solidoid to obtain 1-(4-chlorphenyl)pyrazolidine-3-ketone. By the synthesis process, the solvent can be effectively recovered after the initial reaction of the pyraclostrobin intermediate pyrazolidone is completed, the synthesis cost is reduced, the economic benefit is improved, the synthesis process design of the pyraclostrobin intermediate pyrazolidone is optimized, and the design requirements are met.

Description

technical field [0001] The invention relates to the technical field of pesticide synthesis, in particular to a synthesis process of pyraclostrobin intermediate pyrazolidinone. Background technique [0002] Methoxyacrylate fungicides are a class of low-toxicity, high-efficiency, broad-spectrum, systemic fungicides. They are new fungicides with great development potential and market vitality in the world’s pesticide industry; pyraclostrobin is currently the most active fungicide. A good methoxyacrylate fungicide, which was first developed and researched by BASF in Germany, and was launched in the European market in 2002; pyraclostrobin has the disadvantages of high efficiency, low toxicity, environmental friendliness, and a wide range of crops ; In the short few years since pyraclostrobin was listed, the market of this variety has soared rapidly, and the sales have risen rapidly, and it has been listed as the second place in the market of all bacterial agents, second only to a...

AI Technical Summary

Problems solved by technology

[0006] 1. No agitator is installed inside the oxidation reactor or the agitation parameters are unreasonably set, resulting in low synthesis efficiency and low yield of pyraclostrobin intermediate pyrazolidinone, which is not conducive to large-scale production;

[0007] 2. The organic liquid after desolventization has not been washed with water, resulting in toluene or methanol impurities in the final product, affecting the purity and actual use value of the product, which is not conducive to economy, and does not meet the actual requirements of green environmental protection and safety;

[0008] 3. The toluene recovered by precipitation is directly used in the dehydration kettle for reaction without purification, and new impurities are introduced. The liquid phase obtained after centrifugation is applied to the dehydration kettle for reproduction, which wastes production costs and is not conducive to economy

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