Preparation process for cyproconazole

Abstract

The invention discloses a preparation process for high-purity cyproconazole, which comprises the following steps that: 1-(4-chlorphenyl)-2-cyclopropyl-1-acetone is taken as a raw material which performs an epoxidation reaction with a sulphur Fourier agent in a weak polarity organic solvent in the presence of alkali; the mixture is subjected to washing and desolvation to obtain 2-(4-chlorphenyl)-2-(1-cyclopropyl ethyl)epoxy ethane which is condensed and desolventized with 1,2,4-triazole in the presence of a catalyst to obtain a crude product; the crude product is directly dissolved into an organic solvent without processing, and the mixture reacts with inorganic acid by heating to generate salts of the cyproconazole; the salts of the cyproconazole are filtered and washed to obtain a salt; and the salt is dried and heated in a ceratin amount of water for deacidifying, and then the salt is subjected to filtration, washing and drying to obtain a finished product with high content and yield. The process is not only economical and environment-friendly, but also has the advantages of high purity and yield of the product, no need of recrystalization for a plurality of times, safe operation, convenience and the like.

Description

Technical field [0001] The invention relates to a preparation process of the pesticide ciproconazole. Background technique [0002] Cycloconazole: (2RS, 3RS,)-2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-1,2,4-triazol-1-yl)butan-2-ol (Hereinafter referred to as I) is an important triazole fungicide, is a sterol demethylation inhibitor, has preventive and therapeutic effects, and is used for foliar treatment and seed spraying of important economic crops. [0003] Its structural formula is: [0004] [0005] The main impurities in the synthesized cyproconazole are: (2RS, 3RS,)-2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-1,3,4-triazol-1-yl ) Butan-2-ol (hereinafter referred to as II), due to the similar properties of (I) and (II), it is difficult to separate it by simple recrystallization with general solvents. Therefore, the purity of the general crude product is only about 70-80%, and it is similar to syrup. The same is very sticky and difficult to cure. Since the 1-substituent derivatives...

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Problems solved by technology

[0006] The synthesis process of cyproconazole has been described in more detail in U.S. Patent US4664696 (1987), German Patent DE3406993 (1984) and "Modern Pesticides" Volume 3, No. 4, 2004 (Author: You Huanan), but the above-mentioned In several literatures, the amount of thiolate reagent used in the epoxidation reaction is very large, which not only pollutes the environment, but also has a low yield, which seems very uneconomical

A large amount of anhydrous potassium carbonate was used to catalyze the condensation reaction, which brought a lot of trouble to the post-treatment, especially in the final purification, almost all used silica gel column for chromatographic separation, and then recrystallized with a solvent to obtain a content of more than 95%. products, which is not only time-consuming and laborious, but also seriously limits the production scale of the product, and the cost remains high

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