Method for preparing o-chloroaniline by virtue of solvent-free catalytic hydrogenation

A technology for catalytic hydrogenation and o-chloroaniline, which is applied in the preparation of amino compounds, chemical instruments and methods, preparation of organic compounds, etc., can solve the problems of increased production costs, low catalyst selectivity, etc., and achieves cost savings and is conducive to industrialization. Promote application and solve the effect of solvent recovery

Active Publication Date: 2014-03-26
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantages of CN102050746A and CN101774931A are that the selectivity of the catalyst is not high, and a dechlorination inhibitor needs to be added, which increases the production cost. At the same time, there are problems of dechlorination inhibitor treatment and alcohol solvent recovery
The disadvantage is that it needs to add a variety of additives to inhibit dechlorination, which increases the production cost, and there are problems in the treatment of dechlorination inhibitors and the recovery of alcohol solvents

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Add 60g o-nitrochlorobenzene and 0.36 g3%Pt / C (59.98% water content) catalyst into a 100ml stainless steel autoclave, seal the autoclave, replace the air in the autoclave with nitrogen three times, and then replace it with hydrogen Nitrogen in the kettle for three times and maintain a certain pressure in the kettle. Under stirring, heat up to 95°C, maintain the reaction pressure of 2.25MPa, and react for 120 minutes. After the reaction is over, close the hydrogen valve, let the gas out after cooling, and open the autoclave to discharge the material. Filter out the catalyst. The filtrate is analyzed by high performance liquid chromatography. The conversion rate of benzene is 100%, the selectivity of o-chloroaniline is 99.3%, and the dechlorination rate is 0.09%.

Embodiment 2

[0026] Add 60 g of o-nitrochlorobenzene and 0.36 g of 1% Pt / C (59.78% water content) catalyst into a 100 ml stainless steel autoclave, seal the autoclave, replace the air in the autoclave with nitrogen three times, and then replace it with hydrogen Nitrogen in the kettle for three times and maintain a certain pressure in the kettle. Under stirring, heat up to 95°C, maintain the reaction pressure of 2.25MPa, and react for 120 minutes. After the reaction is over, close the hydrogen valve, let the gas out after cooling, and open the autoclave to discharge the material. Filter out the catalyst. The filtrate is analyzed by high performance liquid chromatography. The conversion rate of benzene is 96%, the selectivity of o-chloroaniline is 99.5%, and the dechlorination rate is 0.06%.

Embodiment 3

[0028] Add 60 g of o-nitrochlorobenzene and 0.36 g of 5% Pt / C (60.12% water content) catalyst into a 100 ml stainless steel autoclave, seal the autoclave, replace the air in the autoclave with nitrogen three times, and then replace it with hydrogen Nitrogen in the kettle for three times and maintain a certain pressure in the kettle. Under stirring, heat up to 95°C, maintain the reaction pressure of 2.25MPa, and react for 120 minutes. After the reaction is over, close the hydrogen valve, let the gas out after cooling, and open the autoclave to discharge the material. Filter out the catalyst. The filtrate is analyzed by high performance liquid chromatography. The conversion rate of benzene is 100%, the selectivity of o-chloroaniline is 98.9%, and the dechlorination rate is 0.39%.

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Abstract

The invention belongs to the technical field of fine chemical engineering, and relates to a method for preparing o-chloroaniline by virtue of solvent-free catalytic hydrogenation ortho-nitrochlorobenzene. The method is characterized in that ortho-nitrochlorobenzene is adopted as a raw material to be reacted with hydrogen in the presence of a catalyst at the temperature of 70-120 DEG C and the pressure of 0.5-5.0 MPa so as to obtain o-chloroaniline through the processing after the reaction. By adopting the method, no solvent is added, the defect for adding the solvent can be overcome, the environmental pollution problem and the solvent recycling problem can be avoided, the equipment investment is reduced, the production cost is reduced, the conversion rate of the ortho-nitrochlorobenzene can reach 100 percent, the selectivity of the o-chloroaniline is more than 99.2 percent, and the dechlorinating rate is less than 0.09 percent.

Description

technical field [0001] The invention belongs to the technical field of fine chemicals, and relates to a new preparation method of o-chloroaniline, in particular to a method for preparing o-chloroaniline by solvent-free catalytic hydrogenation of o-nitrochlorinated benzene. Background technique [0002] O-Chloroaniline is an important intermediate in the industries of pesticides, medicines, spices, dyes, and polyurethane. The preparation of o-chloroaniline in industrial production uses o-nitrochlorobenzene as a raw material, and undergoes a reduction reaction to obtain o-chloroaniline. Due to the serious pollution problems of the iron powder reduction method, alkali sulfide reduction method, and hydrazine hydrate reduction method, they have been eliminated. At present, the commonly used process for the production of o-chloroaniline is to use skeletal nickel as a catalyst, methanol or ethanol as a solvent, and catalytic hydrogenation to reduce o-chloroaniline. Nitrochlorinate...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C211/52C07C209/36
Inventor 吴其建杜建国周亚苓
Owner CHINA PETROLEUM & CHEM CORP
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