Preparation method of 2-chloro-1-(1-chlorocyclopropyl)ethanone

Abstract

The invention discloses a preparation method of 2-chloro-1-(1-chlorocyclopropyl)ethanone. The method comprises the steps as follows: in the presence of a Lewis acid salt catalyst and a quaternary ammonium salt phase transfer catalyst, chlorine is introduced into a solvent system with 1-acetyl-1-chlorocyclopropane dissolved or directly introduced into 1-acetyl-1-chlorocyclopropane, the reaction temperature is controlled at 5-25 DEG C for chlorination, and 2-chloro-1-(1-chlorocyclopropyl)ethanone is prepared. 2-chloro-1-(1-chlorocyclopropyl)ethanone prepared with the method has the advantage that content and molar yield can reach 90% or higher.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis of pesticides, and relates to the synthesis of pesticide intermediates, in particular to a preparation method of the intermediate 2-chloro-1-(1-chlorocyclopropyl)ethanone of the high-efficiency fungicide prothioconazole. Background technique [0002] Prothioconazole is a novel broad-spectrum triazolethione fungicide, as a sterol demethylation (ergosterol biosynthesis) inhibitor (DMIs), its mechanism of action is to inhibit the Demethylation of a sterol precursor - lanosterol or 2,4-methylenedihydrolanosterol at position 14. [0003] Prothioconazole has good systemic action, excellent protection, treatment and eradication activity, and long-lasting effect. Prothioconazole has a wider bactericidal spectrum than other triazole fungicides, and is mainly used for disease control of crops such as wheat, barley, rape, peanut, rice, beans, sugar beet and field vegetables. [0004] Prothiocona...

AI Technical Summary

Problems solved by technology

[0011] 1) When sulfuryl chloride is used for chlorination, a large amount of sulfur dioxide gas will be produced, which will form a mixed acid with hydrogen chloride, a by-product of the chlorination reaction, which is difficult to handle

[0012] 2) When sulfonyl chloride is used alone for chlorination, the reaction rate is slow and the reaction cycle is long, which cannot meet the needs of large-scale industrial production

After adding catalyst alcohols, the reaction speed is improved, but it also increases the difficulty of post-reaction treatment

[0013] 3) The amount of sulfonyl chloride used in the chlorination reaction is relatively large, and its molar amount is 1.5 to 2.0 times that of 1-acetyl-1-chlorocyclopropane, resulting in a large waste of raw materials

[0014] 4) Sulfonyl chloride is easy to decompose and needs to be stored at low temperature

An increase in ambient temperature will cause part of the sulfuryl chloride to decompose into hydrogen chloride and sulfur dioxide, polluting the environment and posing a greater safety risk

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