Dilute sulfuric acid diazotization process of substituted phenylamine

A technology of diazotization and dilute sulfuric acid, applied in azo dyes, organic chemistry, monoazo dyes, etc., can solve the disadvantages of cost reduction and environmental protection, difficulty in controlling coupling temperature, and increased consumption of sulfuric acid and other problems, to achieve the beneficial effects of reducing the amount of freezing and ice usage, increasing equipment, and reducing costs.

Inactive Publication Date: 2014-03-05
JIANGSU JIHUA CHEMICAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Concentrated sulfuric acid (98%) is used in conventional synthesis, but diazotization in concentrated sulfuric acid increases the consumption of sulfuric acid in percent and increases the processing capacity of waste acid after synthesis
The diazonium solution synthesized with concentrated sulfuric acid will release a lot of heat during the coupling synthesis, and the control of the coupling temperature is also relatively difficult. To control the coupling temperature, the freezing or ice required is relatively large.
There are disadvantages of waste of sulfuric acid, high energy consumption, and difficulty in waste acid treatment, which is not conducive to cost reduction and environmental protection requirements

Method used

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  • Dilute sulfuric acid diazotization process of substituted phenylamine
  • Dilute sulfuric acid diazotization process of substituted phenylamine
  • Dilute sulfuric acid diazotization process of substituted phenylamine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Add 20g of 65% sulfuric acid and 39g of 40% nitrosylsulfuric acid solution into a 100ml flask, and add 25g of 6-chloro-2,4-dinitroaniline with stirring at a temperature of 25-30°C. The temperature was kept at ℃ for 3 hours, and it was set aside for coupling.

[0019] In a 2000ml beaker, add 1000g of ice water, 0.5g of OP, 2g of sulfamic acid, 30g of N,N-diallyl-2-methoxy-5-acetamidoaniline, stir for 30 minutes, then add the above diazo solution dropwise Coupling is carried out, and then the disperse blue dye of formula (II) is obtained by filtering and washing with water, and the dye yield is 95%.

[0020]

Embodiment 2

[0022] Add 20g of 95% sulfuric acid and 39g of 40% nitrosylsulfuric acid solution into a 100ml flask, and add 25g of 6-chloro-2,4-dinitroaniline with stirring at a temperature of 25-30°C. The temperature was kept at ℃ for 3 hours, and it was set aside for coupling.

[0023] In a 2000ml beaker, add 1000g of ice water, 0.4g of OP, 2g of sulfamic acid, 24g of N,N-diethyl-3-acetamidoaniline, stir for 30 minutes, add the above diazo solution dropwise for coupling, then filter and wash with water to obtain Formula (Ⅲ) disperse purple dye, dye yield 94%.

[0024]

Embodiment 3

[0026] Add 24g of 40% sulfuric acid and 30g of 40% nitrosylsulfuric acid solution into a 100ml flask, and add 20g of 2,6-dichloro-4-nitroaniline with stirring at a temperature of 25 to 30°C. The temperature was kept at ℃ for 3 hours, and it was set aside for coupling.

[0027] In a 2000ml beaker, add 1000g ice water, 0.4g Pingping O, 2g sulfamic acid, 23g N-cyanoethyl-N-acetoxyethylaniline, after stirring for 30 minutes, drop the above diazo solution for coupling, and then The disperse purple dye of formula (IV) was obtained by filtering and washing with water, and the dye yield was 94.5%.

[0028]

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PUM

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Abstract

The invention discloses a dilute sulfuric acid diazotization process of substituted phenylamine, which comprises the steps of adding substituted phenylamine into 40-95% of dilute sulfuric acid by mass, adding a nitrosyl sulfuric acid solution at a temperature of 0-40 DEG C, and keeping at the temperature for 1-3 hours to obtain a diazonium compound of substituted phenylamine. In the process disclosed by the invention, the original production process and feed amount are not changed when dilute sulfuric acid is used for diazotization, a positive effect is realized on the consumption of sulfuric acid, the energy consumption in coupling and the wastewater treatment, the heat generated by the dilution of concentrated sulfuric acid can be effectively utilized, and the energy consumption of a unit industrial production value is reduced.

Description

technical field [0001] The invention relates to a diazotization preparation method of aniline compounds, in particular to a novel synthesis method in which dilute sulfuric acid is used instead of concentrated sulfuric acid. Background technique [0002] The diazonium reaction is an important reaction process of azo-type compounds. The commonly used process is the diazotization reaction of aniline compounds with nitrosyl sulfuric acid solution in concentrated sulfuric acid medium. The sulfuric acid is used as a solvent for aniline compounds and their diazonium salts, and is the guarantee for the sufficient and effective reaction of diazotization and the stability of the diazonium salts. Concentrated sulfuric acid (98%) is used in conventional synthesis, but diazotization in concentrated sulfuric acid not only increases the consumption of sulfuric acid, but also increases the processing capacity of waste acid after synthesis. The diazonium solution synthesized with concentrat...

Claims

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Application Information

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IPC IPC(8): C07C245/20C09B29/085
Inventor 陆洪汇朱建龙陈美芬
Owner JIANGSU JIHUA CHEMICAL CO LTD
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