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Method for synthesizing 3-chloro-2-methylbiphenyl

A synthesis method and technology of methyl biphenyl, which are applied to the preparation of amino compounds, chemical instruments and methods, preparation of hydroxyl compounds, etc., can solve the problem of increasing the cost of 3-chloro-2-methyl biphenyl products and increasing the cost of coupling reactions. Heat is difficult to control, the atomic economy of bromobenzene is low, etc., to achieve the effect of reasonable design, high safety and low price

Inactive Publication Date: 2019-09-06
王海峻
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The intense heat release of the coupling reaction is difficult to control, and it is easy to cause safety hazards such as flushing and explosion during production. The atom economy of bromobenzene is too low, and the price rises, resulting in an increase in the product cost of 3-chloro-2-methylbiphenyl

Method used

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Embodiment Construction

[0013] Embodiment now further illustrates the present invention.

[0014] 1, a laboratory synthesis method of 3-chloro-2-methylbiphenyl, has the following steps:

[0015] (1) Add 25g of magnesium flakes and 200ml of tetrahydrofuran to a 500ml four-neck bottle, weigh 160g of 2,6-dichlorotoluene in the funnel, first drop 5g of 2,6-dichlorotoluene to initiate the reaction, and then add the remaining 2,6-dichlorotoluene, heat preservation reaction after adding, follow the reaction process by GC, when it is detected that the raw material content is less than 1wt%, cool down to 40°C, add 100g of cyclohexanone dropwise, and react for 1 hour after dropping 300ml was hydrolyzed, 100ml was acidified with 37.5wt% concentrated hydrochloric acid, and the tetrahydrofuran was removed after the oil layer was separated to obtain 220g of crude product;

[0016] (2), add 200ml of toluene and 10ml of 85wt% phosphoric acid to the crude product obtained in step (1), heat up to 110°C for reflux deh...

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PUM

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Abstract

The invention discloses a method for synthesizing 3-chloro-2-methylbiphenyl. Raw materials which are 2,6-dichlorotoluene and cyclohexanone undergo a Grignard addition reaction, post-treatment, a dehydration olefination reaction and a dehydroaromatization reaction to prepare the 3-chloro-2-methylbiphenyl. The method has reasonable design, and the 3-chloro-2-methylbiphenyl is synthesized by reacting2,6-dichlorotoluene with cyclohexanone; dehydration and dehydroaromatization of cyclohexanone are carried out to generate a benzene ring instead of the original bromobenzene for producing the benzenering, so method has the advantages of mild and controllable reaction conditions, and high safety; and the olefination and aromatization accord with the atomic economy, a one-pot process is adopted toavoid waste generation, the cyclohexanone has a lower price than bromobenzene, so the raw material cost of the product is significantly reduced.

Description

technical field [0001] The invention relates to the field of chemical product preparation, in particular to a method for synthesizing 3-chloro-2-methylbiphenyl. Background technique [0002] Bifenthrin, a low-toxicity and high-efficiency pesticide, has a large market share in insecticides. The key intermediate in the production process of bifenthrin is 2-methylbiphenyl-3-methanol (commonly known as biphenyl alcohol). And 2-methylbiphenyl-3-methanol is produced by 3-chloro-2-methylbiphenyl, the preparation method of 3-chloro-2-methylbiphenyl in the prior art is by 2,6- Dichlorotoluene is prepared by coupling reaction with bromobenzene after Grignard reaction. [0003] The exothermic heat of the coupling reaction is severe and difficult to control, and it is easy to cause safety hazards such as flushing and explosion during production. The atom economy of bromobenzene is too low, and the price rises, resulting in an increase in the product cost of 3-chloro-2-methylbiphenyl. ...

Claims

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Application Information

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IPC IPC(8): C07C17/357C07C25/18C07C209/36C07C211/46
CPCC07C17/35C07C17/357C07C29/40C07C209/325C07C2601/14C07C2601/16C07C35/50C07C25/18C07C211/46
Inventor 王海峻葛小红
Owner 王海峻