A kind of synthetic method of prothioconazole

Abstract

A kind of synthetic method of prothioconazole, it passes 2-(1-chloro-cyclopropyl-1-yl)-1-(2-chloro-phenyl)-2-hydroxyl-3-(1,2, 4‑triazolidine‑5‑thione‑1‑yl)‑propane is reacted in the presence of oxygen to prepare prothioconazole, wherein the reaction is carried out in a tower reactor, and the oxygen is fed in the form of air, and the reaction in the presence of a phase transfer catalyst. In the present invention, 2-(1-chloro-cyclopropyl-1-yl)-1-(2-chloro-phenyl)-2-hydroxyl-3-(1,2,4-triazolidine-5- Thione-1-yl)-propane reacts with air in a tower reactor under the action of a catalyst, and high-yield prothioconazole can be directly obtained without adding a reducing agent. The reaction process has high atom utilization and no Three wastes, and the reacted catalyst can be used repeatedly.

Description

technical field [0001] The present invention relates to a kind of synthetic method of prothioconazole. Background technique [0002] Prothioconazole is a new type of broad-spectrum triazolethione fungicide developed by Bayer, mainly used to prevent and control many diseases of cereals, wheat and legumes. Prothioconazole has low toxicity, no teratogenicity, and no mutagenicity. Type, non-toxic to embryos, safe to humans and the environment. [0003] Most of the existing industrial production processes use acetylbutyrolactone as the starting material to synthesize the intermediate 2-(1-chloro-cyclopropyl-1-yl)-1-(2-chloro-phenyl)-2-hydroxy -3-1,2,4-triazolidine-5-thione-1-yl)-propane, and then oxidized with an oxidizing agent to obtain the target product. The most commonly used oxidizing agent is ferric chloride, because the oxidation performance of ferric chloride is relatively mild, and the impurities produced are less, so a higher reaction yield can be obtained. [0004]...

AI Technical Summary

Problems solved by technology

[0005] Patents CN1137103C and CN111269190A use oxygen as an oxidant, which greatly improves the utilization rate of atoms, but because it involves two-phase or even three-phase reactions, and the oxygen oxidation performance is strong, the reaction system is relatively complicated, and it is difficult to directly obtain high yields only through oxygen oxidation Prothioconazole often requires the addition of reducing agents, which not only increases production costs, but also produces three wastes

CN1137103C adopts the scheme of KOH and sulfur powder protection to improve the reaction yield, while CN111269190A directly converts 2-(1-chloro-cyclopropyl-1-yl)-1-(2-chloro-phenyl)-2-hydroxyl-3 -1,2,4-Triazolidin-5-thione-1-yl)-propane is over-oxidized to the intermediate 1 shown in the following formula, and then the intermediate 1 is reduced to the target by a reducing agent such as sodium thiosulfate The product prothioconazole, the above two methods cannot avoid producing a large amount of three wastes due to the introduction of a large amount of reducing agents such as KOH or sodium thiosulfate

Images