A kind of preparation method of prothioconazole intermediate

Abstract

The invention relates to a preparation method of a prothioconazole intermediate. The preparation method comprises the following steps: dissolving [1-(2-chlorophenyl)-2-(1-chlorocyclopropyl)-2-hydroxy]-propyl hydrazine into methyl benzene; dropwise adding a formaldehyde aqueous solution or a polyformaldehyde aqueous solution under 30 to 35 DEG C; then adding in thiocyanate after completion of dropwise adding; then dropwise adding hydrochloric acid or sulfuric acid aqueous solution; keeping warm and reacting for 50 to 70 minutes after completion of dropwise adding; directly using a reaction solution for follow-up reaction or filtering the reaction solution after cooling; thus obtaining the prothioconazole intermediate 2-(1-chloro-cyclopropyl-1-yl)-1-(2-chlorophenyl)-2-hydroxy-3-(1,2,4-triazolidine-5-thioketone-1-yl)-propane. Through optimization on a whole route, for example, reaction temperature, reagents, a feeding procedure and the like, of the preparation method, an after-treatment method is simple, three wastes such as waste gas, waste water and waste residues are few, the reaction time is shortened, the purity and the yield of a product are higher, and the preparation method is suitable for industrial production.

Description

technical field [0001] The present invention relates to a preparation method of prothioconazole intermediate, in particular to a 2-(1-chloro-cyclopropan-1-yl)-1-(2-chlorophenyl)-2-hydroxyl-3- Process for the preparation of (1,2,4-triazolidine-5-thione-1-yl)-propane. Background technique [0002] Prothioconazole (Prothioconazole) is a broad-spectrum, high-efficiency triazolethione fungicide developed by Bayer Corporation of Germany. The English common name: Prothioconazole, the English trade name: Proline, and the original drug is a light brown needle Crystal, CA No. 178928-70-6, chemical name (RS)-2-[2-(1-chlorocyclopropyl)-3-(2-chlorophenyl)-2-hydroxypropyl]-2 ,4-Dihydro-1,2,4-triazole-3-thione is mainly used to control many diseases of cereals, wheat and beans. [0003] Prothioconazole is a racemate, which not only exhibits good systemic activity, excellent protective, therapeutic and eradicating activities for crops, but also has a long duration of action. Through a la...

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Problems solved by technology

Compared with Example 5, this example has a change in the feeding order, resulting in a significant decline in the yield and purity of the product. It can be seen that for this type of reaction, the feeding order has a great influence on the product yield and purity

[0010] In addition, the various examples of CN1137103C show that after the reaction is completed, it needs to be diluted with 100ml of dichloromethane, the solid is filtered out, and the organic liquid phase is concentrated under reduced pressure to obtain the product.

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