Method for preparing cyproconazole with 2,4'-dichloroacetophenone being raw material

Abstract

The invention relates to the field of organic synthesis and especially relates to a method for preparing cyproconazole with 2,4'-dichloroacetophenone being a raw material. The method includes: a) performing a nucleophilic substitution reaction on the 2,4'-dichloroacetophenone and 1,2,4-triazole or 1,2,4-triazole salt to obtain 1-(4-chlorophenyl)-2-(1H-1,2,4-triazole-1-yl)ethyl ketone; b) performing a nucleophilic addition reaction on the 1-(4-chlorophenyl)-2-(1H-1,2,4-triazole-1-yl)ethyl ketone with one or more of a 3-halogenated-1-butylene Grignard reagent, a 3-halogenated-1-butylene organozinc reagent, a 1-halogenated-2-butylene Grignard reagent and a 1-halogenated-2-butylene organozinc reagent, thus generating 2-(4-chlorophenyl)-3-methyl-1-(1H-1,2,4-triazole-1-yl)-4-pentene-2-ol; c) performing a ring forming reaction on the 2-(4-chlorophenyl)-3-methyl-1-(1H-1,2,4-triazole-1-yl)-4-pentene-2-ol with one or more Simmons-Smith reagents prepared from dihalogenated methane, thus preparing the cyproconazole. The preparation method is short in route, gentle in reaction and high in yield. The reactions are free of dangerous reagents, so that the method is suitable for large scale industrial production.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a method for preparing cyproconazole by using 2,4'-dichloroacetophenone as a raw material. Background technique [0002] Cycloconazole is a triazole fungicide developed by Sandoz AG in Switzerland. It is an ergosterol demethylation inhibitor and has preventive and therapeutic effects. It is effective on cereal crops, coffee, sugar beets, fruit trees and grapes. The pathogens of the genus Powdery mildew, Rust, Sporomyces, Coracospora, Septoria, and Scab are all effective, and can control cereal and coffee rust, cereal, fruit tree and grape powdery mildew, peanut, beet leaf Spot, apple scab and peanut white rot can also be mixed with other fungicides. The effective period of preventing and controlling wheat rust is 4-6 weeks, and preventing and controlling powdery mildew is 3-4 weeks. Cycloconazole was first launched in France in 1989 as a fungicide for wheat foliar spraying, and...

AI Technical Summary

Problems solved by technology

[0009] For the first and second synthetic methods, a large amount of highly toxic reagents have been used in the reaction process, such as heavy metal copper, methyl iodide, dimethyl sulfate, etc.; for the third method, although the use of highly toxic reagents has been avoided, its The reaction steps are as high as six steps, the total yield is only 37%, and the reaction economy is relatively poor

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