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Method for preparing 2, 6-dichloro-4-trifluoromethylaniline

A technology of trifluoromethylaniline and dichloride, which is applied in chemical instruments and methods, preparation of amino compounds, preparation of organic compounds, etc., can solve the problems such as difficulty in handling the rectifying kettle, and achieves less generation of three wastes, simple process, The effect of short reaction time

Pending Publication Date: 2022-05-17
ZHEJIANG WEIHUA NEW MATERIAL CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the problem that the rectification still residue produced by the continuous production of m-trifluoromethylaniline is not easy to handle, the invention provides a method for preparing 2,6-dichloro-4-trifluoromethylaniline. Utilization of resources, turning waste into treasure, simple process, short reaction time, no need for melt crystallization and the prepared 2,6-dichloro-4-trifluoromethylaniline has a high yield and purity

Method used

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  • Method for preparing 2, 6-dichloro-4-trifluoromethylaniline

Examples

Experimental program
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Effect test

Embodiment 1

[0034] Add 1000g hydrochloric acid (8%), 80g m-trifluoromethylaniline rectification raffinate (p-trifluoromethylaniline 72.5%, m-trifluoromethylaniline 25.5%) in the reaction bottle, stir, and the raffinate is all dissolved . After the temperature was raised to 40°C, chlorine gas was introduced, and the reaction temperature was maintained at 50°C to 60°C. The reaction was monitored by GC, and the reaction was stopped when the content of 2,4-dichloro-5-trifluoromethylaniline was equal to 0.18%. Neither methylaniline nor 2-chloro-4-trifluoromethylaniline was detected, and the reaction time was 45 minutes. The reaction solution was statically separated, and the lower organic phase was washed with 100mL lye (2%), then evaporated under reduced pressure to remove water, and then rectified under reduced pressure to obtain 2,6-dichloro-4-trifluoromethylaniline 73.2 g, the GC purity is 99.74%, and the yield is 88.4% based on p-trifluoromethylaniline. The above percentages are all per...

Embodiment 2

[0036] Add 726g hydrochloric acid (12%), 67g m-trifluoromethylaniline rectification raffinate (p-trifluoromethylaniline 69.6%, m-trifluoromethylaniline 28.4%) in the reaction bottle, stir and raffinate is all dissolved, After the temperature was raised to 40°C, chlorine gas was introduced, and the reaction temperature was maintained at 50°C-60°C. The reaction was detected by GC, and the reaction was stopped when the content of 2,4-dichloro-5-trifluoromethylaniline was equal to 0.23%. Neither methylaniline nor 2-chloro-4-trifluoromethylaniline was detected, and the reaction time was 38 minutes. The reaction solution was statically separated, and the lower organic phase was washed with 100mL lye (2%), then evaporated under reduced pressure to remove water, and then rectified under reduced pressure to obtain 2,6-dichloro-4-trifluoromethylaniline 58.4 g, the GC purity is 99.63%, and the yield is 87.6% based on p-trifluoromethylaniline. The above percentages are all percentages by...

Embodiment 3

[0038] Add 1600g hydrochloric acid (20%), 160g m-trifluoromethylaniline rectification raffinate (p-trifluoromethylaniline 71.2%, m-trifluoromethylaniline 26.9%) in the reaction bottle, stir and raffinate is all dissolved, After the temperature was raised to 40°C, chlorine gas was introduced, and the reaction temperature was maintained at 50°C-60°C. The reaction was detected by GC, and the reaction was stopped when the content of 2,4-dichloro-5-trifluoromethylaniline was equal to 0.11%. Neither methylaniline nor 2-chloro-4-trifluoromethylaniline was detected, and the reaction time was 55 minutes. The reaction solution was statically separated, and the lower organic phase was washed with 100mL lye (2%), then evaporated under reduced pressure to remove water, and then rectified under reduced pressure to obtain 2,6-dichloro-4-trifluoromethylaniline 141.8 g, the GC purity is 99.77%, and the yield is 86.9% based on p-trifluoromethylaniline. The above percentages are all percentages...

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Abstract

The invention discloses a method for preparing 2, 6-dichloro-4-(trifluoromethyl) aniline and a preparation method of the 2, 6-dichloro-4-(trifluoromethyl) aniline. The method for preparing 2, 6-dichloro-4-trifluoromethylaniline comprises the following steps: enabling m-trifluoromethylaniline residues in a rectifying still to react with chlorine in a solvent until the content of 2, 4-dichloro-5-trifluoromethylaniline in reaction liquid is less than or equal to 0.3%, thereby obtaining the 2, 6-dichloro-4-trifluoromethylaniline, the rectifying still residue of the m-trifluoromethylaniline is prepared from the following components: 69.6 percent to 72.5 percent of p-trifluoromethylaniline and 25.5 percent to 28.4 percent of the m-trifluoromethylaniline; the solvent is water or hydrochloric acid. The process is simple, melt crystallization is not needed, the purity of the prepared 2, 6-dichloro-4-trifluoromethylaniline product is up to 99.5%, and the percentage is mass percentage.

Description

technical field [0001] The invention relates to a method for preparing 2,6-dichloro-4-trifluoromethylaniline. Background technique [0002] Patent CN 101538206A discloses a process for synthesizing 2,6-dichloro-4-trifluoromethylaniline by dissolving benzotrifluoride reaction kettle residue in hydrochloric acid, adding hydrogen peroxide for oxychlorination reaction. The still residue treated and utilized in this method is the raffinate obtained by batch nitration of benzotrifluoride, hydrogenation reduction, and redistillation, and its composition is: the content of m-trifluoromethylaniline is 6% to 10%, The content of methylaniline is 30%-60%, and the rest is N-alkyl-3-trifluoromethylaniline and a small amount of polymer. [0003] The inventor found in the research and development process that the components of the residues produced by different processes are quite different, and the residues produced by continuous nitration and hydrogenation reduction processes contain mor...

Claims

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Application Information

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IPC IPC(8): C07C211/52C07C209/74C07C209/86
CPCC07C209/74C07C209/86C07C211/52
Inventor 谢四维卜健鸿李俊奇潘强彪姚振文郑泽阳杜乐乐方超
Owner ZHEJIANG WEIHUA NEW MATERIAL CO LTD
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