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Application of solid acid catalyst to preparation of 2,5-dichloronitrobenzene

A technology of solid acid catalyst and dichloronitrobenzene, which is applied in the preparation of nitro compounds, organic chemistry, etc., can solve the problems of low product purity, incomplete reaction, and long reaction time, and achieve simplified reaction steps and complete reaction , the effect of high utilization rate

Active Publication Date: 2011-11-30
JIANGSU LONGCHANG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, the production of 2,5-dichloronitrobenzene at home and abroad is to use nitric acid or a mixed acid method composed of nitric acid and sulfuric acid, but the traditional reaction system uses a stirred tank to stir the reaction for a long time, the reaction is incomplete, the yield is low, and the product purity is high. not tall

Method used

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  • Application of solid acid catalyst to preparation of 2,5-dichloronitrobenzene

Examples

Experimental program
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Effect test

Embodiment 1

[0013] Put 1 mole part of p-toluenesulfonic acid and 1.25 mole parts of p-dichlorobenzene in a reaction kettle and stir and mix until uniform; the above materials are added dropwise at a temperature of 110 ° C. 1.3 molar parts of nitric acid were used for nitration reaction.

[0014] In the above nitration reaction, the material is an external circulation reaction, and the reaction kettle is specially made. The structure of the reactor is shown in the figure.

[0015] An outlet 2 is provided at the top of the kettle body 1 of the reaction kettle, an inlet 3 is arranged at the bottom, and a pipe 4 is used to connect the outlet 2 and the inlet 3, and a lifting pump 5 is arranged on the pipe 4 . When in use, the raw material enters the pipeline 4 from the outlet 2 at a flow rate of 5T / h through the lifting pump, and then returns to the kettle body 1 from the inlet 3, and the reciprocating cycle reacts for 6-8 hours to ensure that the material is fully reacted for 6-8 ho...

Embodiment 2

[0019] Put 0.8 mole parts of p-toluenesulfonic acid and 1.25 mole parts of p-dichlorobenzene in a reaction kettle and stir and mix them until they are uniform; 1.3 molar parts of nitric acid were used for nitration reaction.

[0020] In the above nitration reaction, the material is an external circulation reaction, and the reaction kettle is specially made. The structure of its reactor is identical with embodiment 1. The raw material enters the pipeline 4 through the lift pump from the outlet 2 at a flow rate of 5T / h, and the reciprocating cycle reacts for 4-6 hours to ensure that the material is fully reacted for 5 hours.

[0021] After the nitration reaction is completed, the temperature is controlled at 105° C. for 1-2 hours. After that, let it stand for 0.5 hours. After the temperature drops to 100°C, p-toluenesulfonic acid reaches the freezing point and forms a solid. The crude product of 2,5-dichloronitrobenzene is in a liquid state. Using the different freezing ...

Embodiment 3

[0024] Put 1.2 mole parts of p-toluenesulfonic acid and 1.25 mole parts of p-dichlorobenzene in a reaction kettle and stir and mix them until they are uniform; 1.3 molar parts of nitric acid were used for nitration reaction.

[0025] In the above nitration reaction, the material is an external circulation reaction, and the reaction kettle is specially made. The structure of its reactor is identical with embodiment 1. The raw material enters the pipeline 4 through the lift pump from the outlet 2 at a flow rate of 5T / h, and the reciprocating cycle reacts for 8-10 hours to ensure that the material is fully reacted for 8 hours.

[0026] After the nitration reaction is completed, the temperature is controlled at 110° C. for 1-2 hours. After that, let it stand for 0.5 hours. After the temperature drops to 100°C, p-toluenesulfonic acid reaches the freezing point and forms a solid. The crude product of 2,5-dichloronitrobenzene is in a liquid state. Using the different freezing...

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Abstract

The invention discloses application of a solid acid catalyst to preparation of 2,5-dichloronitrobenzene. The preparation method comprises the following steps of: fully mixing p-toluenesulfonic acid serving as a catalyst and a p-dichlorobenzene solution in a kettle, dripping 98 mass percent concentrated nitric acid, performing nitration reaction at certain temperature, keeping the temperature after the reaction is finished, and standing; performing solid-liquid separation to obtain a crude product of 2,5-dichloronitrobenzene; and neutralizing the obtained crude product to reach a certain pH value range by using caustic soda, washing with water, and separating to obtain pure 2,5-dichloronitrobenzene. The p-toluenesulfonic acid is used as the catalyst, reaction steps are effectively simplified, and the emission of wastewater and waste liquor is reduced; materials are reacted completely and the utilization rate is high when the 2,5-dichloronitrobenzene is prepared by external circulation nitration reaction; and the finished product prepared by the method has the yield of 125 percent, and the content is more than or equal to 99.8 percent.

Description

technical field [0001] The invention relates to a solid acid catalyst applied to the preparation of 2,5-dichloronitrobenzene. 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 for 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 quizalofop. 2,5-Dichloronitrobenzene is also the main raw material for the synthesis of antibacterial agent triclosan, therefore, the production and development prospects of domestic 2,5-Dichloronitrobenzene are still promising. [0003] At present, the production of 2,5-dichloronitrobenzene at home and abroad is to...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C205/12C07C201/08
Inventor 佘道才王兆昌张剑宇吴春江
Owner JIANGSU LONGCHANG CHEM
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