Preparation method of efficient haloxyfop-methyl

Abstract

The invention discloses a preparation method of efficient haloxyfop-methyl. The preparation method comprises the following steps: (a) adding 2-(4-hydroxy phenoxy) serving as a first intermediate into a first reaction kettle, performing esterification reaction, then adding methylbenzene serving as a solvent, and preparing a 2-(4-hydroxy phenoxy)ethyl propionate methylbenzene solution; (b) adding 6-chloride-2-sulfydryl benzoxazole serving as a second intermediate into a second reaction kettle, performing chlorination, then adding methylbenzene serving as the solvent, and preparing a 2-6-dichloro benzoxazole methylbenzene solution; (3) adding methylbenzene serving as the solvent into a third reaction kettle, feeding potassium carbonate and a catalyst, and feeding the intermediates in the first reaction kettle and the second reaction kettle into the third reaction kettle; (d) after the reaction is ended, cooling to 25 DEG C, discharging a material, performing centrifugation, and finally obtaining a product through an ethanol recrystallization process. According to the preparation method of the efficient haloxyfop-methyl, the reaction time can be greatly shortened; furthermore, feeding of a solid intermediate is avoided, the influence of an excitant intermediate on the skin of a human body is effectively reduced, and release of polluting gas is reduced.

Description

technical field [0001] The invention relates to a preparation method of fine chemical products, in particular to a preparation method of high-efficiency haloxyfop-pamide. Background technique [0002] 2-[4-(6-Chloro-2-benzoxazolyloxyphenoxy)] ethyl propionate, also known as fenoxaprop-ethyl, belongs to 2-(4-aryloxyphenoxy) propionate Acid herbicides. [0003] Fenoxaprop-ethyl is used to control annual and perennial grass weeds in sugar beet, cotton, flax, peanut, rape, potato, soybean and vegetable fields; it has high efficiency and low toxicity, wide insecticidal spectrum, long application period and good effect on crops It can avoid the harm of various harmful organisms to crops and promote the growth of crops. Its use is one of the important measures to increase the output per unit area of ​​agriculture and has made an important contribution to alleviating the world food crisis. [0004] Due to the preparation of two intermediates 2,6-dichlorobenzoxazole and 2-(4- Hydr...

AI Technical Summary

Problems solved by technology

[0004] Due to the preparation of two intermediates 2,6-dichlorobenzoxazole and 2-(4- Hydroxyphenoxy) ethyl propionate is a crystalline solid at room temperature, so it needs to be heated and melted every time it is produced, and it has obvious irritating effects on human skin and eyes. At the same time, 2-(4-hydroxybenzene Oxygen) ethyl propionate has optical properties and is prone to optical degradation in the heating process, resulting in relatively complicated preparation methods and low yield