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Method for preparing 2, 4-dinitro-6-bromoaniline through two stages of oxybromination

A technology of dinitroaniline and oxidative bromination is applied in the preparation of amino compounds, chemical instruments and methods, preparation of organic compounds, etc., and can solve the problems of high production cost, inability to recycle and apply, and large amount of post-treatment, and achieve no The effect of three wastes discharge

Active Publication Date: 2015-03-25
昌邑新澳化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore bromine-sodium hypochlorite method is mainly used to prepare 2,4-dinitro-6-bromoaniline at present in production, and sodium hypochlorite produces a large amount of inorganic salts as oxidizing agent, forms waste hydrochloric acid containing a large amount of inorganic salts that cannot be recycled, and the amount of aftertreatment large, expensive to produce

Method used

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Examples

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Comparison scheme
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specific Embodiment approach

[0031] The present invention will be further described below through specific examples, but not limited thereto.

[0032] The raw materials used in the examples are conventional raw materials, and the equipment used are conventional equipment, commercially available products.

Embodiment 1

[0034] A method for preparing 2,4-dinitro-6-bromoaniline by two-stage oxidative bromination, comprising the following steps:

[0035] (1) In a 1000mL four-neck flask with stirring, thermometer, and reflux condensing device, add 500mL of hydrochloric acid with a concentration of 20wt%, add 92.42g (0.5mol) of 2,4-dinitroaniline with a purity of 99%, and heat To 50°C, fully stir until the 2,4-dinitroaniline is completely dissolved, add 44g (0.275mol) of bromine dropwise within 2.5h, after the drop is completed, continue to keep warm for 30min to make the bromine react completely;

[0036] (2) In the reaction system of step (1), at 50 DEG C, feed 5.5g (0.0775mol) of chlorine gas within 2h, and continue the insulation reaction for 30min;

[0037] (3) Add 20.4 g (0.12 mol) of hydrogen peroxide with a concentration of 20 wt % dropwise at 50° C. within 3 h to the reaction system of step (2), and continue the heat preservation reaction for 1 h;

[0038] (4) Cool the product obtained i...

Embodiment 2

[0041] A method for preparing 2,4-dinitro-6-bromoaniline by two-stage oxidative bromination, comprising the following steps:

[0042](1) In a 1000mL four-neck flask with stirring, thermometer, and reflux condensing device, add 600mL of hydrochloric acid with a concentration of 15wt%, add 92.42g (0.5mol) of 2,4-dinitroaniline with a purity of 99%, and heat To 57°C, fully stir until the 2,4-dinitroaniline is completely dissolved, add 44g (0.275mol) of bromine dropwise within 3.5h, after the drop is completed, continue to keep warm for 30min to make the bromine react completely.

[0043] (2) Into the reaction system of step (1), at 57° C., 5.29 g (0.0.0745 mol) of chlorine gas was introduced within 1.5 h, and the reaction was continued for 30 min.

[0044] (3) Add 28.6 g (0.126 mol) of hydrogen peroxide with a concentration of 15 wt % dropwise at 57° C. within 3 h to the reaction system in step (2), and continue the heat preservation reaction for 1.5 h.

[0045] (4) Cool the pro...

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Abstract

The invention relates to a method for preparing 2, 4-dinitro-6-bromoaniline through two stages of oxybromination. The method comprises the steps that (1) 2, 4-dinitraniline is added to hydrochloric acid with the concentration being 10-35wt%, then the 2, 4-dinitraniline and the hydrochloric acid are evenly stirred, bromine is dripped into the mixture, and a stirring reaction continues to be carried out for 10-60 min; (2) chlorine is supplied to a reaction system in the step (1), after chlorine supply is completed, a heat preservation reaction continues to be carried out for 10-50 min; (3) hydrogen peroxide is dripped into the reaction system in the step (2), and the heat preservation reaction continues to be carried out for 10-60 min again; (4) a prepared product from the step (3) is filtered, washed and dried, and therefore the 2, 4-dinitro-6-bromoaniline is obtained. According to the method, the generated by-product in the oxybromination process of chloride is hydrogen chloride, the generated by-product in the oxybromination process of the hydrogen peroxide is water, hydrochloric acid is formed, no other by-products except mother liquor is generated, and green industrial production is achieved.

Description

technical field [0001] The invention relates to a method for preparing 2,4-dinitro-6-bromoaniline by two-stage oxidative bromination, and belongs to the technical field of preparation of organic intermediate 2,4-dinitro-6-bromoaniline. Background technique [0002] 2,4-Dinitro-6-bromoaniline (alias: 6-bromo-2,4-dinitroaniline; 2-bromo-4,6-dinitroaniline), molecular formula: C 6 h 4 BrN 3 o 4 , Molecular Weight: 262.02, Appearance: Yellow Needle Crystal, Melting Point: 153-154°C. Soluble in hot water and hot acetone, soluble in hot acetic acid, mainly used as an intermediate of disperse dyes. [0003] The brominated dyes produced by 2,4-dinitro-6-bromoaniline are high-grade dyes, which have a bright color and can improve the colorability and fastness of the dye, and have a large market capacity. 2,4-Dinitro-6-bromoaniline is obtained by brominating 2,4-dinitroaniline with bromine in hydrochloric acid medium. For example, CN103073434A discloses a synthesis technology of ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C211/52C07C209/74
Inventor 付忠东高建伟徐丕法万克玲徐少华
Owner 昌邑新澳化工有限公司
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