Synthesis method of 2, 3, 5-trichloropyridine

A synthetic method, the technology of triclopyridine, which is applied in the field of pesticide chemical industry, can solve the problems of fewer synthesis steps, harsh conditions, and difficult control, and achieve the effects of simple product post-treatment, mild reaction conditions, and less heavy metal pollution

Active Publication Date: 2021-01-01
常州沃腾化工科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method has easy-to-obtain raw materials and fewer synthesis steps, but the process operation is cumbersome, involves high-pressure reactions, and the conditions are relatively harsh, difficult to control, and a large number of catalysts must be applied, such as cuprous chloride, which cannot be recycled and used mechanically, and will pollute the environment. , and the product yield is not ideal

Method used

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  • Synthesis method of 2, 3, 5-trichloropyridine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] Add chloral (240 grams, 1.62 moles) and acrylonitrile (95 grams, 1.79 moles) to the flask and mix well, then add 12 grams of cuprous chloride, 0.24 grams of hydroquinone and 2.4 grams of polyethylene glycol Alcohol 200, reacted at 85°C for 30 hours, then filtered, separated the catalyst, and then distilled under reduced pressure. When no liquid flowed out, 2,4,4-trichloro-4-formylbutyronitrile reaction liquid was obtained. (Wherein, the quality of 2,4,4-trichloro-4-formylbutyronitrile is 310 grams, 1.54 moles, purity 95.5%, yield 94.9%), need not separate, then be warming up to 80 ℃, slowly pass through Add 120 grams (3.28 moles) of hydrogen chloride gas and react for 3 hours. After the reaction is complete, distill under reduced pressure to obtain 240 grams (3.28 moles) of 2,3,5-trichloropyridine with a purity of 99.2% and a yield of 80.8%.

Embodiment 2

[0035] Add chloral (240 grams, 1.62 moles) and acrylonitrile (95 grams, 1.79 moles) in the flask and mix well, then add 12 grams of cuprous chloride, 0.24 grams of hydroquinone and 2.4 gram of polyethylene glycol 200, reacted at 85°C for 30 hours, then filtered, separated the catalyst, and then distilled under reduced pressure. When no liquid flowed out, 2,4,4-trichloro-4-formylbutyl Nitrile reaction liquid, (wherein, the quality of 2,4,4-trichloro-4-formylbutyronitrile is 309 grams, 1.54 moles, purity 95.9%, yield 94.6%), need not separate, then be heated up to 80 ℃, 120 g (3.28 moles) of hydrogen chloride gas was slowly introduced into it, and reacted for 3 hours. After the reaction was complete, it was distilled under reduced pressure to obtain 238 g of 2,3,5-trichloropyridine with a purity of 99.0% and a yield of 80.1%.

Embodiment 3

[0037] Add chloral (240 grams, 1.62 moles) and acrylonitrile (172 grams, 3.24 moles) to the flask and mix well, then add 12 grams of cuprous chloride, 0.24 grams of hydroquinone and 2.4 grams of polyethylene glycol Alcohol 200, reacted at 85°C for 30 hours, then filtered, separated the catalyst, and then distilled under reduced pressure. When no liquid flowed out, 2,4,4-trichloro-4-formylbutyronitrile reaction liquid was obtained. (Wherein, the quality of 2,4,4-trichloro-4-formylbutyronitrile is 311 grams, 1.54 moles, purity 96.5%, yield 95.3%), need not separate, then be warming up to 80 ℃, slowly pass through Add 120 g (3.28 moles) of hydrogen chloride gas and react for 3 hours. After the reaction is complete, distill under reduced pressure to obtain 241.7 g of 2,3,5-trichloropyridine with a purity of 99.5% and a yield of 81.4%.

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Abstract

The invention relates to a synthesis method of 2, 3, 5-trichloropyridine. The method comprises the following steps: (1) in the presence of a phase transfer catalyst and a polymerization inhibitor, carrying out chemical reaction on trichloroacetaldehyde, acrylonitrile and the catalyst at 60-90 DEG C to prepare an intermediate product 2, 4, 4-trichloro-4-formyl butyronitrile; and (2) heating a reaction solution obtained in the step (1) to 60-100 DEG C, and slowly introducing hydrogen chloride gas into the reaction solution to carry out cyclization reaction, thereby preparing the target compound2, 3, 5-trichloropyridine. The synthesis method has the advantages of mild reaction conditions, no need of harsh reaction conditions, such as high temperature, high pressure and reaction solvent, recyclable catalyst, less heavy metal pollution, high target product yield (up to 80%), high purity (up to 99%), simple post-treatment of the product, and reduced cost, and is suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of pesticide chemical industry, and in particular relates to a synthesis method of 2,3,5-trichloropyridine. Background technique [0002] 2,3,5-Trichloropyridine is an important fine chemical intermediate, which is widely used in the fields of medicine and pesticide research, and can be used to prepare various herbicides and insecticides. 2,3,5-Trichloropyridine reacts with alkali metal hydroxide to prepare 3,5-dichloro-2-pyridinol, which is an important raw material for synthesizing a series of pesticides such as insecticidal mite and herbicide oxafluben. 2,3,5-trichloropyridine can also be further fluorinated to synthesize 2,3-difluoro-5-chloropyridine, which is the basic raw material for the synthesis of the herbicide clodinafop-propargyl. [0003] After reviewing the literature, it was found that there are many feasible technological routes for the chemical synthesis of 2,3,5-trichloropyridine. US4111938 describ...

Claims

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Application Information

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IPC IPC(8): C07D213/61
CPCC07D213/61Y02P20/584
Inventor 曹伟
Owner 常州沃腾化工科技有限公司
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