Clean chlorobenzene liquid phase nitration method having superior para-selectivity

A green production and selective technology, applied in the direction of nitro compound preparation, chemical recovery, organic chemistry, etc., can solve the problems of industrial application limitations, accelerated inactivation speed, poor thermal stability, etc., to prevent pollution, separate Ease of use and the effect of a small amount of catalyst

Inactive Publication Date: 2009-04-22
YANGZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Chlorobenzene liquid phase nitration process has been applied in recent years SO 4 2- /M x o y type solid superacid catalyst reports, but in the liquid-solid reaction system, SO 4 2- /M x o y The sulfate radi

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Example

[0023] Comparative example 1

[0024] Add 15ml of chlorobenzene into the reaction vessel containing 50ml of carbon tetrachloride solvent, stir and mix at a temperature of 10~15℃, slowly add 25ml of 66.5% (weight) nitric acid dropwise, and add 2gWO after the addition is complete 3 / ZrO 2 Solid super acid catalyst, heated to 60°C and stirred at constant temperature for 6h. After the reaction is over, cool to room temperature, filter to recover the catalyst and separate the organic phase, use 5.0% (weight) NaHCO 3 The aqueous solution and water are washed to near neutrality, the solvent is recovered by distillation and then dried and dehydrated to obtain the product nitrochlorobenzene.

[0025] According to the gas chromatographic analysis result, the mononitrate product yield was 82.9%, and the adjacent ratio was 26:74% (weight).

[0026] It can be seen that under the same conditions, the yield is less than 91.5% without adding acetic anhydride, a water absorbent.

Example

[0027] Comparative example 2

[0028] Add 15ml of chlorobenzene and 20ml of acetic anhydride into the reaction vessel containing 50ml of carbon tetrachloride solvent, stir and mix at a temperature of 10~15℃, slowly add 25ml of 66.5% (weight) nitric acid dropwise, after the addition is complete The temperature was increased to 60°C and the reaction was stirred at a constant temperature for 6 hours. After the reaction is over, cool to room temperature, separate the organic phase, and use 5.0% (weight) NaHCO 3 The aqueous solution and water are washed to near neutrality, the solvent is recovered by distillation and then dried and dehydrated to obtain the product nitrochlorobenzene.

[0029] According to the gas chromatographic analysis result, the yield of mononitrate product was 6%, and the adjacent ratio was 35:65% (weight).

[0030] It can be seen that under other conditions are the same, WO is not used 3 / ZrO 2 The solid super acid catalyst has extremely low yield and cannot be u...

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PUM

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Abstract

The invention provides a green production method for selectively nitrifying chlorobenzene liquid phase, and relates to a synthesis technology of nitro-chlorobenzene. The method comprises the following steps: adding chlorobenzene and water absorber into a reaction container filled with carbon tetrachloride solvent; stirring and mixing the chlorobenzene, the water absorber and the carbon tetrachloride solvent at a temperature of between 10 and 15 DEG C; dripping nitrating agent into the mixture; after finishing dripping, adding catalyst WO3/ZrO2 into the mixture, and heating to a temperature of between 50 and 60 DEG C; stirring the mixture to react full;, filtering and recycling the catalyst, separating and washing organic phase to approximate neutral; and after distilling and recycling the solvent, drying and dehydrating the solvent to obtain the nitro-chlorobenzene product. The nitrified product prepared by the method has a yield as high as 91.5 percent, and shows favorable contraposition selectivity; and the method has the advantages that the method has little catalyst dosage and easy separation, can recycle and prevent pollution from sources, so that the green production method for selectively nitrifying the chlorobenzene liquid phase has good industrial application prospect.

Description

technical field [0001] The present invention relates to the synthetic technology of nitrochlorobenzene. Background technique [0002] Nitrochlorobenzene is an intermediate of chemical products such as synthetic dyes, pesticides, medicines, developers and rubber anti-aging agents. It is also a good high-boiling solvent and moderate organic oxidant, and has a wide range of uses in industry. At present, the domestic industrial production of nitrochlorobenzene mostly adopts the traditional nitric acid mixed acid liquid-phase nitration method. Although the reaction temperature of this method is low and the nitration yield is high, the process selectivity is poor, and the product separation after the nitration reaction is difficult. It is complex, and a large amount of waste acid and organic acid wastewater will be produced in the production process, resulting in serious environmental pollution. At the same time, the strong corrosiveness of the mixed acid will seriously damage the...

Claims

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Application Information

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IPC IPC(8): C07C205/12C07C201/08
CPCY02P20/584
Inventor 张存刘涛马春艳
Owner YANGZHOU UNIV
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