Simple method for preparing cyproconazole by cyclopropyl methyl ketone

Abstract

The invention relates to a simple method for synthesizing cyproconazole through cyclopropyl methyl ketone. P-chlorobenzyl choride VI is taken as a starting raw material to prepare into a Grignard reagent which performs nucleophile substitution reaction with the cyclopropyl methyl ketone to generate alcohol VII; the alcohol VII is dehydrated in the presence of ortho-position benzene ring and oxygen phosphorus chloride to form conjugated alkene VIII; hydroxyl is introduced at benzyl position through hydroboration oxidation reaction to obtain alcohol IX; Dess-Martin oxidation is carried out on the obtained alcohol to obtain ketone IV; Darzens condensation is performed on the ketone IV and sulfonium iodide at alkalescence condition to further obtain cyproconazole through ring opening of triazole. The invention is a cyproconazole synthesizing method with simple operation, good safety, environmentally friendliness and high yield, can realize industrialized production, and satisfy heavy demands of agricultural production to cyproconazole.

Description

technical field [0001] The present invention relates to a convenient method for synthesizing cyproconazole by cyclopropyl methyl ketone. 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 later as a seed treatment agent, widely used in th...

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Problems solved by technology

[0014] As can be seen from the above two routes, there is a common shortcoming in the process of industrially synthesizing cyclaconazole. A large amount of highly toxic reagents are used in the reaction process, such as heavy metal copper, methyl iodide, dimethyl sulfate, etc., which are difficult to obtain. To meet the requirements of today's green chemical synthesis, it is necessary to find a green method for synthesizing the precursor of cyclaconazole

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