Application of antioxidant in distillation reaction of 2, 5-dichloroaniline

An antioxidant and dichloroaniline technology, which is applied in the production of fine chemical intermediates, can solve the problems of inability to preserve the color and appearance of materials for a long time, poor anti-oxidation effect, poor heat resistance, etc., and achieve the anti-oxidation effect of products Good, good anti-oxidation effect, low production cost

Active Publication Date: 2013-12-25
HULUDAO TIANQI SHENGYE CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the past, although the antioxidants and methods used in the production of 2,5-dichloroaniline had a certain antioxidant effect on the product,

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0008] The reaction is carried out in a distillation still containing a certain amount of 2,5-dichloroaniline mixture, and the steam valve is opened to raise the temperature of the distillation still to about 140°C, ensuring that the steam pressure is above 4kg. When backflow occurs in the sight glass on the top floor, take a sample through the sampling port and check the pH. Determine the input amount of antioxidant according to the pH value, add antioxidant, and start stirring. When backflow occurs in the backflow sight glass, full backflow is performed for 1 hour. Open the extraction valve of the front distillate a small amount, and observe the output through the sight glass. The initial fore distillation can be recovered normally after 3 hours (the output is a thin line in the sight glass or liquid flowing down along the mirror wall) ) before extraction, the distillate should not be too fast, and it is better to control it within 12-18 hours per kettle without breaking th...

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PUM

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Abstract

The invention relates to an application of an antioxidant in distillation reaction of 2, 5-dichloroaniline. The process comprises the following steps: simultaneously adding a generated crude product, namely the 2, 5-dichloroaniline and the antioxidant into a distillation kettle after the reaction of 2, 5-dichloronitrobenzene and hydrogen is completed and reacting during the distillation process to get a final product, namely p-chloroaniline. The antioxidant comprises the component of sodium sulfide, and the concentration is 0.1%. The temperature of the distillation reaction is 130 DEG C, and the pH value during the reaction process is 10-11. The application disclosed by the invention has the advantages that compared with other antioxidants, the application of the antioxidant has better stability, good heat resistance and good oxidation resistance, and can keep the color and the appearance of the material for a long time. The application disclosed by the invention further has the advantages of simple process, low production cost, low toxicity and good oxidation resistance of the product, and is suitable for green industrial production.

Description

Technical field: [0001] The invention relates to a process for producing fine chemical intermediates, in particular to the application of an antioxidant in the distillation reaction of 2,5-dichloroaniline. Background technique: [0002] Antioxidants are substances that prevent oxidation of products, slow down or prevent oxidation. The use of antioxidants will not change the color and appearance of the product due to deterioration and affect the final product yield. Distillation is a thermodynamic separation process. It utilizes the different boiling points of the components in the mixed liquid or liquid-solid system to evaporate the low-boiling components and then condense them to separate the entire components. There are two types of evaporation and condensation. A union of unit operations. During the distillation process, the color and appearance of the material will change, which is essentially an oxidation reaction. After oxidation, the color and appearance of the prod...

Claims

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Application Information

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IPC IPC(8): C07C211/52C07C209/90
Inventor 杨向党陈晨赵洋洋
Owner HULUDAO TIANQI SHENGYE CHEM
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