Synthetic method for bactericide of silthiopham

Abstract

The invention relates to a synthetic method for bactericide of silthiopham, and the synthetic method comprises the following steps of: enabling 4,5-dimethyl-2-(trimethyl silica based) thiophene-3-methyl formate and allyl amine to flow back in a solvent I for reaction for 5-15 hours, cooling to room temperature after reaction, washing, and obtaining an organic phase through drying, concentration and recrystalization; or firstly evaporating the solvent I under negative pressure after reaction, then cooling to room temperature, washing, extracting dichloromethane, and obtaining the organic phase through drying, concentration and recrystalization, wherein the feeding molar ratio of 4,5-dimethyl-2-(trimethyl silica based) thiophene-3-methyl formate and allyl amine is 1:(1-2). The method has the characteristics that the raw material is cheap and easily available, the reaction temperature is mild, the reaction yield is high and the like, thus being applicable to large-scale production.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and specifically relates to a fungicide N-allyl-4,5-dimethyl-2-(trimethylsilyl)thiophene-3-carboxamide (silthiocarbamide) resolve resolution. Background technique [0002] Sithiopyram is a fungicide developed by Monsanto Corporation of the United States for the prevention and treatment of wheat take-all, and has a significant effect on the control of wheat take-all. However, its popularization and application are limited due to the problems of raw material supply and harsh reaction conditions in the current synthesis process. [0003] U.S. Patent US005486621A reports its synthesis method, which uses 2-butanone, sulfur, cyanoacrylate, etc. as starting materials to synthesize the target product, but the total yield is less than 10%. Moreover, the steps of the synthesis method are long, and the separation of each intermediate is difficult. US Patent US006140511A reports an improved synt...

AI Technical Summary

Problems solved by technology

However, due to its current synthesis process, there are problems such as raw material supply and harsh reaction conditions, which limit its popularization and application.

[0003] U.S. Patent US005486621A reports its synthetic method, and this method takes 2-butanone, sulfur, cyanoacrylate, etc. as starting materials to synthesize the target product, But the total yield is less than 10%

And this synthetic method step is long, each intermediate is difficult to separate etc.

U.S. Patent US006140511A has reported an improved synthetic method, but the synthesis of the important intermediate 3-(trimethylsilyl) propynamide involved in this method has encountered great challenges

Although this patent provides a variety of synthesis methods, the synthesis methods involved are either difficult to obtain raw materials, or require the use of strong bases sensitive to water and air such as butyllithium or amide lithium, which are difficult to popularize and apply; in addition, due to the The intermediate has a higher boiling point, and its separation and purification have also encountered difficulties

Document Organic Process Research & Development 6 (2002), 357-366 has reported new synthetic route, and this synthetic method has synthesized target product with mercaptobutanone, methyl methoxyacrylate as starting material, although this process yield has However, the reaction conditions are harsh, and air-sensitive dangerous raw materials such as butyllithium or lithium amide (LDA) are still required, making it difficult to produce on a large scale

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