A kind of method that catalyzes the epoxidation of triazolene to prepare epoxiconazole

Abstract

The invention relates to the field of pesticides, and particularly relates to a method of preparing epoxiconazole by catalyzing epoxidation of triazole olefin. The epoxiconazole can be prepared by steps of: subjecting a ligand and manganese ion to in-situ formation of an active catalyst species, fully stirring and dissolving the active catalyst species and the substrate triazole olefin, putting the mixture at -10-60 DEG C, adding an oxidation agent in mole 5-8 times of that of the triazole olefin, and reacting for 6-24 h. The catalyst has characteristics of simple preparation, low cost, high chemical selectivity when being applied for catalyzing the triazole olefin to synthesize the epoxiconazole, low concentration of needed hydrogen peroxide, high yield, good stability, mild reaction conditions, and green, nontoxic or low-toxicity solvent.

Description

technical field [0001] The invention relates to the field of pesticides, in particular to a method for preparing epoxiconazole by catalyzing the epoxidation of triazolene. Background technique [0002] Epoxiconazole is a broad-spectrum triazole fungicide with high efficiency, low toxicity and low residue, which was developed by BASF in 1985. It has been reported in the literature that there are six synthetic routes for the original drug of epoxiconazole, and triazolene is used to synthesize epoxiconazole in industrial production. Patent U.S.5245042 uses maleic anhydride and hydrogen peroxide to form monoperoxymaleic acid in situ to epoxidize triazolene. This process uses maleic anhydride 10 times the molar amount of triazolene, which is equivalent to producing 1 ton of fluorine rings Azole produces 3.52 tons of maleic acid, and the generation of a large amount of waste acid increases the post-treatment steps and also brings huge pressure to the environment; at the same time...

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Problems solved by technology

Patent U.S.5245042 uses maleic anhydride and hydrogen peroxide to form monoperoxymaleic acid in situ to epoxidize triazolene. This process uses maleic anhydride 10 times the molar amount of triazolene, which is equivalent to producing 1 ton of fluorine rings Azole produces 3.52 tons of maleic acid, and the generation of a large amount of waste acid increases the post-treatment steps and also brings huge pressure to the environment; at the same time, the process route uses hydrogen peroxide with a mass concentration of 50%, and the use of high-concentration hydrogen peroxide exists in production. Huge potential safety hazard; and this process route uses environmentally unfriendly dichloroethane as a solvent

It was reported that 8-hydroxyquinoline manganese complexes were used to catalyze the epoxidation of olefins (ZL200610136989.4). The catalyst for this method needs to be prepared in advance, and this catalytic system is only effective for simple, electron-rich alkenes. The catalytic effect on triazolene, which is a large hindrance and electron-deficient olefin, is relatively poor

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