Method for enhancing nitration reaction rate of 2,5-dichloronitrobenzene

A technology of dichloronitrobenzene and nitration reaction, which is applied in the field of increasing the nitration reaction rate of 2,5-dichloronitrobenzene, and can solve the problems of difficult recycling of waste acid, low atom economy, high treatment cost and mixed acid , to achieve the effect of being easy to recycle and reuse, easy to separate, recycle and reuse, and improve the profit margin of the enterprise

Inactive Publication Date: 2014-12-24
XIAMEN UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

These processes not only have low atom economy, but also produce a large amount of waste acid and organic acid wastewater in the production process, resulting in serious environmental pollution and high treatment costs; the strong corrosiveness of the mixed acid will also seriously damage the equipment; side reactions such as multiple nitrification and oxidation, and the waste acid is difficult to recycle, resulting in serious safety hazards

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] A method for improving the nitration reaction rate of 2,5-dichloronitrobenzene:

[0024] Material selection: p-dichlorobenzene and ZrO 2 / SO 4 2- The feeding molar ratio is 40:1.

[0025] The reaction steps are as follows:

[0026] To the ZrO of p-dichlorobenzene 73.5g and 4.675g equipped with more than 99% mass fraction 2 / SO 4 2- Put it into the reaction kettle, add 50ml of 98% concentrated nitric acid dropwise, carry out the nitration reaction at 62°C for 1 hour, keep it at 71°C for 4.5 hours, after the reaction is complete, keep the temperature and let it stand for 1 hour to obtain 2,5-di The crude chloronitrobenzene is then neutralized with liquid caustic soda to make 2,5-dichloronitrobenzene alkaline with a pH value of 8, and finally washed with water and routinely separated to obtain pure 2,5-dichloronitrobenzene phenylbenzene (94.8g).

[0027] In this example, the yield of 2,5-dichloronitrobenzene is 98.75%, the product purity can reach 99.8%...

Embodiment 2

[0029] Material selection: p-dichlorobenzene and ZrO 2 / SO 4 2- The feeding molar ratio is: 100:1.

[0030] 73.5g of p-dichlorobenzene and 1.87g of ZrO are equipped with more than 99% mass fraction 2 / SO 4 2- In the kettle, add 50ml of 98% concentrated nitric acid dropwise, carry out nitration reaction at 65°C for 2 hours, maintain 68°C for 1 hour, after the reaction is complete, keep the temperature and let it stand for 1 hour to obtain 2,5-dichloronitrate The crude product of phenylbenzene is neutralized with liquid caustic soda, so that 2,5-dichloronitrobenzene is alkaline with a pH value of 8, and finally washed with water and separated to obtain pure product 2,5-dichloronitrobenzene 94.08 g.

[0031] The 2,5-dichloronitrobenzene productive rate that present embodiment makes is more than 98%, and green solid acid catalyst ZrO 2 / SO 4 2- No need for waste acid treatment, high catalytic activity, easy to recycle and reuse, no side reactions such as oxidation, th...

Embodiment 3

[0033] Material selection: p-dichlorobenzene and ZrO 2 / SO 4 2- The feeding molar ratio is: 1:1.

[0034] To the p-dichlorobenzene 73.5g and 73.5g ZrO with more than 99% mass fraction 2 / SO 4 2- In the kettle, add 50ml of 98% concentrated nitric acid dropwise, carry out the nitration reaction at 60°C for 1 hour, keep the temperature at 75°C for 1 hour, after the reaction is complete, keep the temperature and let it stand for 1 hour to obtain 2,5-dichloronitrate The crude benzene is neutralized with liquid caustic soda to make 2,5-dichloronitrobenzene alkaline with a pH value of 7 to 9, and finally washed and separated with water to obtain pure 2,5-dichloronitrobenzene Benzene 95.1g.

[0035] The 2,5-dichloronitrobenzene productive rate that present embodiment makes is more than 99.06%, and green solid acid catalyst ZrO 2 / SO 4 2- No need for waste acid treatment, high catalytic activity, easy to recycle and reuse, no side reactions such as oxidation, the purity of...

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PUM

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Abstract

The invention discloses a method for enhancing nitration reaction rate of 2,5-dichloronitrobenzene, which is characterized by adding a nano solid acid catalyst ZrO2/SO4<2-> into a reaction kettle filled with paradichlorobenzene and dropwisely adding nitric acid to perform nitration reaction. The catalyst ZrO2/SO4<2-> used in the method is a green solid acid catalyst, and is used instead of concentrated sulfuric acid to solve the problem of secondary environmental pollution of waste acids; the catalyst ZrO2/SO4<2-> has more efficient nitration reaction catalysis capacity, and is easy to separate and recycle; the method has the advantages of controllable temperature and small basic heat output of reaction, is beneficial to enhancing the product yield, does not need to treat the waste acids, does not generate oxidation and other side reactions, has high catalytic activity, and is a green nitration method which is easy for recovery and recycling; the yield of the prepared 2,5-dichloronitrobenzene is above 99%; the solid acid catalyst ZrO2/SO4<2-> does not need waste acid treatment, does not generate oxidation and other side reactions and is recyclable; and the product has high purity, and the content is above 99.8%.

Description

technical field [0001] The invention relates to a method for increasing the nitration reaction rate of 2,5-dichloronitrobenzene, which belongs to the field of chemical reaction technology. Background technique [0002] 2,5-Dichloronitrobenzene, as a nitrogen fertilizer synergist, has the effect of nitrogen fixation and fertilizer preservation, and can also be used as an intermediate of dyes, pesticides, and antibacterial agents. In the dye industry, it is used for ice dyeing dyes such as scarlet base GG, red base 3GL, red base Rc, etc., and can also prepare 2,5-dichloroaniline as a dye intermediate. In the pesticide industry, it is used as a pesticide intermediate, and is an intermediate of the herbicides dicamba and zaheopyl. 2,5-Dichloronitrobenzene is also the main raw material for the synthesis of antibacterial agent triclosan, therefore, the domestic production and development prospects of 2,5-Dichloronitrobenzene are still promising. [0003] Nitrification is...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C201/08C07C205/12
Inventor 郑南峰吴春江张剑宇
Owner XIAMEN UNIV
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