New synthesis method of high-content quizalofop-ethyl intermediate

Abstract

The invention discloses a new synthesis process of a quizalofop-ethyl pesticide intermediate high-purity 2-(4-hydroxyphenoxy)-6-chloroquinoxalin. The synthesis process comprises the following steps of: adding 2, 6-dichloroquinoxaline and hydroquinone into a mixed solvent; heating the mixed solvent, and dripping liquid alkali; carrying out thermal insulation reaction after dripping, separating out an organic solvent after reaction; and cooling, discharging and washing to obtain a high-purity target. With the adoption of the process, the excess ratio of hydroquinone and the sewage production difficulty are greatly lowered. The new synthesis process is a green process.

Description

technical field [0001] The invention relates to a production process of quizalofop pesticide intermediate, in particular to a new process for preparing high-purity 2-(4-hydroxyphenoxy)-6-chloroquinoxaline. Background technique [0002] 2-(4-Hydroxyphenoxy)-6-chloroquinoxaline is the key intermediate for the synthesis of quizalofop-pyl, and its synthesis technology determines the production cost and technical level of quizalofop-pyl. [0003] There are two main processes for the domestic production of 2-(4-hydroxyphenoxy)-6-chloroquinoxaline, one is a pure organic solvent system, that is, first hydroquinone sodium salt is formed in toluene, and then mixed with dichloroquinoxaline The disadvantage of this method is that the reaction time is long and the yield is low; the other is an organic solvent-water mixed system ("ZL201010200215"), which uses a phase transfer catalyst to achieve better results, but due to hydroquinone, Especially its sodium salt is very easy to oxidize, ...

AI Technical Summary

Problems solved by technology

[0003] There are two main processes for the domestic production of 2-(4-hydroxyphenoxy)-6-chloroquinoxaline, one is a pure organic solvent system, that is, first hydroquinone sodium salt is formed in toluene, and then mixed with dichloroquinoxaline The disadvantage of this method is that the reaction time is long and the yield is low; the other is an organic solvent-water mixed system ("ZL201010200215"), which uses a phase transfer catalyst to achieve better results, but due to hydroquinone, Especially its sodium salt is very easy to oxidize, and still does not overcome the problem that the proportion of hydroquinone is too large

As the price of hydroquinone rises and the treatment of phenol-containing sewage becomes more difficult, this excessive production mode of hydroquinone will inevitably lead to a rise in production costs and an increase in environmental protection pressure, and excessive hydroquinone Part of the by-products of phenol oxidation enters the product, which has a great impact on the quality of 2-(4-hydroxyphenoxy)-6-chloroquinoxaline