Production method of 3,4-dichloro aniline

A technology of dichloroaniline and production method, which is applied in 3 fields, can solve the problems of high risk, serious dechlorination, environmental pollution, etc., and achieve the effects of low cost, inhibition of dechlorination, and high yield

Inactive Publication Date: 2006-01-25
ZHEJIANG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The synthesis methods of 3,4-dichloroaniline usually include iron powder reduction method, alkali sulfide reduction method and catalytic hydrogenation method. The first two synthesis methods seriously pollute the environment. The main problem of catalytic hydrogenation method is that hydrogen must be used. Since hydrogen is a flammable gas, it is very

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Add 3 grams of Ru-Fe / Al to a fixed-bed reactor with a length of 10 cm and a diameter of 1.0 cm 2 o 3 catalyst. Add 20 grams of 3,4-dichloronitrobenzene into 490 ml of ethanol with a mass percentage of 95% ethanol aqueous solution to prepare a 5 mass percent 3,4-dichloronitrobenzene reaction solution. Raise the reaction temperature of the fixed-bed reactor to 180°C, and at the same time pass the prepared reaction liquid through the reactor at a flow rate of 0.2ml / min to carry out hydrogen production by ethanol cracking and reductive hydrogenation of 3,4-dichloronitrobenzene . Collect the reaction liquid that flows out from fixed-bed reactor, analyze the content of each component with gas chromatography, the result shows, 3, the conversion rate of 4-dichloronitrobenzene is 100%, and the selectivity of 3,4-dichloroaniline is 96.8%. The reaction liquid is distilled to obtain 3,4-dichloroaniline.

Embodiment 2

[0021] Add 3 grams of Ru-Fe / Al to a fixed-bed reactor with a length of 10 cm and a diameter of 1.0 cm 2 o 3 catalyst. Add 40 grams of 3,4-dichloronitrobenzene into 490 ml of 95% ethanol aqueous ethanol to prepare a 9.2 mass percent 3,4-dichloronitrobenzene reaction liquid. Raise the reaction temperature of the fixed-bed reactor to 180°C, and at the same time pass the prepared reaction solution through the reactor at a flow rate of 0.5ml / min to carry out hydrogen production by ethanol cracking and reductive hydrogenation of 3,4-dichloronitrobenzene . Collect the reaction liquid that flows out from fixed-bed reactor, analyze the content of each component with gas chromatography, the result shows, 3, the conversion rate of 4-dichloronitrobenzene is 88.6%, and the selectivity of 3,4-dichloroaniline is 97.2%. The reaction liquid is distilled to obtain 3,4-dichloroaniline.

Embodiment 3

[0023] Add 3 grams of Ru-Fe / Al to a fixed-bed reactor with a length of 10 cm and a diameter of 1.0 cm 2 o 3 catalyst. The mass percentage of 20 grams of 3,4-dichloronitrobenzene is added to the mass percentage of 490ml ethanol is that the mass percentage of ethanol is in the ethanol aqueous solution of 95%, is made into the 3,4-dichloronitrobenzene of 5 mass percentage content The reaction solution. Raise the reaction temperature of the fixed-bed reactor to 150°C, and at the same time, pass the prepared reaction solution through the reactor at a flow rate of 0.3ml / min to carry out hydrogen production by ethanol cracking and reductive hydrogenation of 3,4-dichloronitrobenzene . Collect the reaction liquid that flows out from fixed-bed reactor, analyze the content of each component with gas chromatography, the result shows, 3, the conversion rate of 4-dichloronitrobenzene is 99.3%, and the selectivity of 3,4-dichloroaniline is 99.3%. The reaction liquid is distilled to obta...

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PUM

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Abstract

The invention provides a process for preparing 3,4-dichloroaniline, which comprises using 3,4-dichloro nitrobenzene as raw material, carrying out reduction reaction at 130-180 deg. C at the presence of alcoholic solution and catalyst, wherein the catalyst is Ru-Fe/Al203, and the amount of the catalyst is 1-40 wt% of 3,4-dichloronitrobenzene. The invention realizes high yield and low making cost, and dehydrogenation can be inhibited effectively.

Description

(1) Technical field [0001] The invention relates to a preparation method of 3,4-dichloroaniline, in particular to a method for preparing 3,4-dichloroaniline by liquid-phase catalytic hydrogenation of 3,4-dichloronitrobenzene. (2) Background technology [0002] 3,4-Dichloroaniline is an important chemical intermediate for medicines, pesticides, dyes, spices, etc., and has a wide range of uses. The synthesis methods of 3,4-dichloroaniline usually include iron powder reduction method, alkali sulfide reduction method and catalytic hydrogenation method. The first two synthesis methods seriously pollute the environment. The main problem of catalytic hydrogenation method is that hydrogen must be used. Because hydrogen is a flammable gas, it is very dangerous in production, and it is difficult to store and transport, and most small and medium-sized enterprises have no hydrogen source, which directly affects the popularization and application of catalytic hydrogenation, an advanced p...

Claims

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Application Information

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IPC IPC(8): C07C211/52C07C209/36
Inventor 严新焕李小年孙军庆
Owner ZHEJIANG UNIV OF TECH
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