Synthesis method of 2-chloro-6-chloroquinoxaline

A technology of hydroxyquinoxaline and synthetic method, which is applied in the field of organic synthesis, can solve problems such as inability to obtain social and economic benefits, unfavorable large-scale industrial production of quizalofop-pyl-ethyl, and achieve saving of investment and production costs and reduction of alkaline wastewater , Stable effect of production and application

Active Publication Date: 2011-01-12
JINGBO AGROCHEM TECH CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Due to the existence of the above-mentioned shortcomings, it is not conducive to the large-sc

Method used

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  • Synthesis method of 2-chloro-6-chloroquinoxaline

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Experimental program
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Effect test

Embodiment 1

[0024] Closed loop reaction stage:

[0025] Put 300kg of solid sodium hydroxide into a 5000L reactor, stir 1000kg of methanol solution, prepare an alkaline solvent, pass cooling water to cool down to 25±5°C, and then put in 400kg of p-chloro-o-nitroacetoacetanilide, at 25±5 React at ℃ for 3 hours, then slowly raise the temperature to 60-65℃, react for 2 hours, take a tracking sample, and use liquid chromatography to analyze whether the reaction of p-chloro-o-nitroacetylacetanilide is complete. If the tracking result is p-chloro-o-nitroacetyl If the content of acetanilide is less than 0.1%, it can be processed. If the tracking result shows that the content of p-chloro-o-nitroacetoacetanilide is > 0.1%, the reaction time needs to be extended for 2 hours, and then follow up until the reactant is p-chloro-o-nitroacetoacetanilide Aniline < 0.1% can be processed in the next step;

[0026] Reduction reaction stage:

[0027] Put 200kg of sodium hydrosulfide and 500kg of methanol int...

Embodiment 2

[0031] Closed loop reaction stage:

[0032] Put 180kg of potassium hydroxide solid and 800kg of acetone solution into a 3000L reaction kettle, start stirring, prepare an alkaline solvent, pass cooling water to cool down to 25±5°C, and then put in 260kg of p-chloro-o-nitroacetoacetanilide, at 25±5°C React at 5°C for 3 hours, then slowly raise the temperature to 60-65°C, react for 2 hours, take a tracking sample, and use liquid chromatography to analyze whether the reaction of p-chloro-o-nitroacetoacetanilide is complete, if the tracking result is p-chloro-o-nitro If the content of acetoacetanilide is less than 0.1%, it can be processed. If the tracking result shows that the content of p-chloro-o-nitroacetoacetanilide is more than 0.1%, it is necessary to prolong the reaction time before tracking. Until the reactant p-chloro-o-nitroacetoacetanilide content reaches the requirements.

[0033] Reduction reaction stage:

[0034]Put 200kg of sodium hydrosulfide and 500kg of acetone...

Embodiment 3

[0042] Preparation of lye for ring closure reaction:

[0043] Measure 800Kg of methyl tert-butyl ether in a 3000L reactor, turn on the agitator, put in 150Kg of sodium hydroxide, pass cooling water to cool down to 20-30°C, and then put in 400Kg of p-chloro-o-nitroacetoacetanilide, at 20- 30°C heat preservation reaction for 3 hours, slowly raise the temperature to 50°C with steam, and heat preservation reaction for 2 hours;

[0044] Reduction reaction:

[0045] Put 500Kg of methyl tert-butyl ether and 150Kg of potassium borohydride into the reaction kettle, slowly raise the temperature to 60°C with steam, and react under slight reflux for 20 hours. metal salt;

[0046] Acidification reaction stage:

[0047] In the acidification reaction stage, the existing acidification method is used for acidification, and the product content measured by liquid chromatography is 97.1%, and the yield is 90.2%.

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Abstract

The invention belongs to the field of organic synthesis, providing a synthesis method in which an organic solvent is used as a synthesis environment of 2-chlorine-6-chloroquinoxaline. The method adopts p-chloro-m-nitroacetoacetanilide as a starting raw material, and a metal salt is obtained through closed loop, reduction and crystallization in the organic solvent under the alkaline condition. The technology is adopted to improve the stability of the whole synthesis reaction. Compared with the traditional technology, the method has the advantages of simple and practicable operation, high yield and content, wherein the use and the recycle of the organic solvent can greatly reduce the generation of waste water, relieve the pollution of environment and reduce production cost.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis and relates to a synthesis method of quizalofop-p-ethyl intermediate 2-chloro-6-hydroxyquinoxaline. Background technique [0002] Quizalofop-ethyl is a highly selective new dry field stem and leaf treatment agent, the chemical name is (R)-2-[4-(6-chloroquinoxalin-2-yloxy)phenoxy]ethyl propionate , and 2-chloro-6-hydroxyquinoxaline is an important intermediate for the synthesis of quizalofop-p-ethyl. Its pure product is white with pink flaky crystals, and its industrial product is light yellow to pink powder, which is produced under alkaline conditions Salt, unstable under acidic conditions. [0003] At present, the method for synthesizing 2-chloro-6-hydroxyquinoxaline in China mainly uses p-chloro-o-nitroacetanilide as the starting material, and undergoes three steps of ring closure, reduction and crystallization in an alkaline environment. This technology is widely used in China. rela...

Claims

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Application Information

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IPC IPC(8): C07D241/44
Inventor 马韵升綦非刘英贤张建林
Owner JINGBO AGROCHEM TECH CO LTD
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