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Preparation method of 2-chlorobenzyl chloride Grignard reagent

A technology of benzyl chloride Grignard and methylmagnesium chloride Grignard is applied in the synthesis field of 2-chlorobenzyl chloride Grignard reagent, can solve problems such as troublesome handling, poor safety, low boiling point, etc., achieves easy clean production and reduces impurities , the effect of high purity

Inactive Publication Date: 2018-05-08
LIMIN CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] (3) ether is used as the reaction solvent, which has a low boiling point and poor safety; after using toluene and tetrahydrofuran mixed solvent, it is troublesome to deal with

Method used

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  • Preparation method of 2-chlorobenzyl chloride Grignard reagent
  • Preparation method of 2-chlorobenzyl chloride Grignard reagent
  • Preparation method of 2-chlorobenzyl chloride Grignard reagent

Examples

Experimental program
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Effect test

Embodiment 1

[0030] The preparation method of 2-chlorobenzyl chloride Grignard reagent comprises the following steps:

[0031] a. After replacing the 3000L clean Grignard reactor with nitrogen, under the protection of nitrogen, add 200kg of tetrahydrofuran with a water content of less than 100ppm and 60kg of magnesium chips. The reaction system was closed, and 0.5 kg of methyl bromide was added to initiate the reaction. 135.9kg of methyl chloride was introduced at 65-70°C, and 1600kg of tetrahydrofuran with a water content of less than 100ppm was added at a constant speed. After the addition was complete, it was stirred at 70°C for 1 hour. Keep the temperature of the methylmagnesium chloride Grignard reactor at 40°C-50°C.

[0032] b. Catalyst Cl 4 CuLi 2 Preparation: under the protection of nitrogen, 85g of anhydrous lithium chloride and 135g of anhydrous copper chloride were dissolved in 1500g of tetrahydrofuran with a water content of less than 100ppm.

[0033] c. At the same time, ...

Embodiment 2

[0035] The preparation technology of 2-chlorobenzyl chloride Grignard reagent comprises the following steps:

[0036] a. After replacing the 3000L clean Grignard reactor with nitrogen, under the protection of nitrogen, add 200kg of tetrahydrofuran with a water content of less than 100ppm and 60kg of magnesium chips. The reaction system was closed, and 0.5 kg of methyl bromide was added to initiate the reaction. 135.9kg of methyl chloride was introduced at 65-70°C, and 1600kg of tetrahydrofuran with a water content of less than 100ppm was added at a constant speed. After the addition was complete, it was stirred at 70°C for 1 hour. Keep the temperature of the methylmagnesium chloride Grignard reactor at 40°C-50°C.

[0037] b. Catalyst Cl 4 CuLi 2 Preparation: Dissolve 85g of anhydrous lithium chloride and 135g of anhydrous copper chloride in 1500g of tetrahydrofuran with a water content of less than 100ppm.

[0038] c. At the same time, after nitrogen replacement in anothe...

Embodiment 3

[0040] The preparation technology of 2-chlorobenzyl chloride Grignard reagent comprises the following steps:

[0041] a. After replacing the 3000L clean Grignard reactor with nitrogen, under the protection of nitrogen, add 200kg of tetrahydrofuran with a water content of less than 100ppm and 60kg of magnesium chips. The reaction system was closed, and 0.5 kg of methyl bromide was added to initiate the reaction. 135.9kg of methyl chloride was introduced at 65-70°C, and 1600kg of tetrahydrofuran with a water content of less than 100ppm was added at a constant speed. After the addition was complete, it was stirred at 70°C for 1 hour. Keep the temperature of the methylmagnesium chloride Grignard reactor at 40°C-50°C.

[0042] b. Catalyst Cl 4 CuLi 2 Preparation: Under the protection of nitrogen, 85g of anhydrous lithium chloride and 135g of anhydrous copper chloride were dissolved in 1500g of tetrahydrofuran with a water content of less than 100ppm.

[0043] c. At the same ti...

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Abstract

The invention discloses a preparation method of a fungicide prothioconazole key intermediate of a 2-chlorobenzyl chloride Grignard reagent. Compared with the prior art: in the presence of a catalyst,a methyl magnesium chloride Grignard reagent is added dropwise into 2-chlorobenzyl chloride to conduct Grignard reaction, the method changes a process route and choice of raw materials; a product witha total yield reaching 98 % (based on the 2-chlorobenzyl chloride) is obtained; a preparation process is simple and easy to implement, reaction speed is fast, side reaction is small, a by-product methyl chloride can be recycled to achieve clean and environment-friendly production, and economic benefits are remarkable.

Description

technical field [0001] The invention relates to the preparation of a key intermediate of the pesticide fungicide prothioconazole, in particular to a method for synthesizing 2-chlorobenzylclo Grignard reagent. Background technique [0002] 2-Chlorobenzyl-Grignard reagent, also known as o-chlorobenzyl-Grignard reagent, is a key intermediate for the preparation of the fungicide prothioconazole. [0003] The method for the preparation of 2-chlorobenzyl chloride Grignard reagent that domestic adopts at present is to use ether or toluene, tetrahydrofuran mixed solvent, make 2-chloro benzyl chloride and metallic magnesium react and generate 2-chlorobenzyl chloride Grignard reagent, but this method has the following shortcoming: [0004] (1) Caused by bad reaction. [0005] (2) direct reaction of 2-chlorobenzyl chloride and magnesium will inevitably produce about 20% coupling impurities, and the coupling impurities structural formula is as follows: [0006] [0007] (3) Ether ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07F3/02
CPCC07F3/02
Inventor 李新生孙敬权蒋跃尹拥军李林虎杨桂红孙丽梅郑翠秀
Owner LIMIN CHEM CO LTD
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