New synthesis method of high-content quizalofop-ethyl intermediate

A synthetic method and high-purity technology, applied in the field of new technology for the preparation of high-purity 2-(4-hydroxyphenoxy)-6-chloroquinoxaline, can solve the problem of chloroquinoxaline’s quality impact, rising production costs, and benzene Diphenol ratio is too large and other problems

Inactive Publication Date: 2012-11-14
ANHUI FENGLE AGROCHEM
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  • Abstract
  • Description
  • Claims
  • Application Information

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

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0012] Example 1: Add 20g dichloroquinoxaline (0.1mol), 11.3g hydroquinone, 1ml methanol, 1ml toluene and 100ml water to a 250ml four-necked flask, stir and heat up to reflux, then dropwise add 12.8g liquid caustic soda to react After 6 hours, the organic solvent was removed, hot filtered, and the filter cake was washed with hot water to obtain 26.8 g of off-white needle-like crystals with a content of 98.7% and a molar yield of 97.1%.

example 2

[0013] Example 2: Add 40g dichloroquinoxaline (0.2mol), 22.5g hydroquinone, 5ml methanol, 5ml toluene and 150ml water to a 500ml four-necked flask, stir and heat up to reflux, then dropwise add 25.5g of liquid caustic soda to react After 6 hours, the organic solvent was removed, filtered with hot water, and the filter cake was washed with hot water to obtain 53.5 g of off-white needle-like crystals with a content of 98.2% and a molar yield of 96.4%.

[0014] Example 3: In a 500ml four-necked flask, add 40g dichloroquinoxaline (0.2mol), recover about 10ml of organic solvent, 22.5g hydroquinone, 1ml methanol, 1ml toluene and 140ml water in "Example 2", stir and heat up To reflux, then dropwise added 25.5g of liquid caustic soda, reacted for 6 hours, removed the organic solvent, filtered with hot water, washed the filter cake with hot water, and obtained 53.8g of off-white needle-like crystals with a content of 98.6% and a molar yield of 97.3%.

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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, ...

Claims

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Application Information

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IPC IPC(8): C07D241/44
Inventor 苏朝辉周康伦王多斌陈克付
Owner ANHUI FENGLE AGROCHEM
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