Method for synthesizing herbicide fenoxaprop-p-ethyl

Abstract

The invention discloses a method for synthesizing fenoxaprop-p-ethyl, which comprises the following steps: dissolving 2,6-dichlorobenzoxazole in acetone at the temperature of 20-25 DEG C; mixing ethylR-(+)-2-(4-hydroxyphenoxy) propionate, inorganic base, a catalyst and water, and stirring at 60-65 DEG C to obtain a mixed solution; heating to 70-75 DEG C, dropwise adding the 2,6-dichlorobenzoxazole acetone solution into the mixed solution, after dropwise adding is completed, carrying out heat preservation reaction at 70-75 DEG C, evaporating out acetone in the reaction process, and collectingan acetone aqueous solution; standing and layering the reaction solution, adding water to wash an organic phase at 70-75 DEG C, then removing water to obtain a fenoxaprop-p-ethyl crude product, and recrystallizing with ethanol to obtain a fenoxaprop-p-ethyl product. According to the fenoxaprop-p-ethyl product disclosed by the invention, the content of effective optical rotation bodies in the fenoxaprop-p-ethyl product is 99.9% or above. Acetone is distilled off at atmospheric pressure in the reaction process, and high-purity recovery of the distilled acetone aqueous solution can be realized byadopting a membrane separation technology.

Description

technical field [0001] The invention belongs to the field of pesticide weeding, and in particular relates to a method for synthesizing the herbicide fenoxaprop-ethyl. Background technique [0002] Fenoxaprop-ethyl, chemically named (R)-2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy]ethyl propionate, is a new type of hetero Ring herbicide, with high efficiency, low toxicity, and less environmental pollution; Fenoxaprop-ethyl is effective in preventing and controlling gramineous weeds in crops such as wheat and rye, such as acorns, wild oats, and foxtails. Very good control effect. The traditional process of synthesis of fenoxaprop-ethyl is a solid-liquid phase reaction, and the synthesis method has serious shortcomings. In addition, a large amount of organic solvents are used in the production process, resulting in a large amount of nitrogen-containing wastewater, which is difficult to treat in the later stage. At present, there is also the preparation of fenoxaprop-ethyl by liqu...

AI Technical Summary

Problems solved by technology

The traditional synthetic reaction process of fenoxaprop-ethyl is a solid-liquid phase reaction, and the synthesis method has serious shortcomings, and a large amount of organic solvents are used in the production process, resulting in a large amount of nitrogen-containing wastewater, which is difficult to treat in the later stage

At present, there is also a liquid phase reaction to prepare fenoxaprop-ethyl, but there are large-scale separation of organic solvents or mixed solvents in the production process

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