Synthetic method of p-aminobenzenesulfonamide

A technology for the synthesis of sulfanilamide and its synthesis method, which is applied in the synthesis of benzenesulfonamide and the field of synthesis of p-aminobenzenesulfonamide, which can solve the problems of increasing chlorosulfonic acid, excessive sewage, and unresolved acid waste water, so as to reduce the consumption Effect

Inactive Publication Date: 2016-01-13
SUZHOU WUGAN PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

This new technology allows for better production efficiency without requiring excessive amounts of harmful chemicals or solvents during manufacturing processes. It also reduces costs due to less waste generated from these steps.

Problems solved by technology

This patented technical issue addressed in this patents relates to how current methods produce p-ammothrenearnitrile have issues such as generating excessive amounts of harmful chemical compounds like halogen gas during manufacturing processes due to their high volatility and low purity levels compared to other synthetic intermediaries commonly found around them.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] This embodiment provides a method for synthesizing p-aminobenzenesulfonamide, which sequentially includes the following steps:

[0013] (A) Add 25 mol of chlorosulfonic acid to the reaction kettle, control the temperature at 40°C, and continuously add 10 mol of acetanilide (add it slowly according to the conventional method, and complete the addition within 1.5~2h), and then increase the temperature to 55°C and react for 2h to obtain paraacetamido The first mixture of benzenesulfonic acid and acetaminobenzenesulfonic acid chloride,

[0014] (B) Add 2 mol of dichloroethane to the first mixture, raise the temperature to 65°C, and then drop 0.25 mol DMF and 5 mol SOCl 2 The mixture of acetamidobenzene sulfonic acid is converted into acetaminobenzene sulfonyl chloride by adding dropwise in 0.5~1h according to the conventional method.

[0015] (C) Control the temperature of the reactor at 15°C, slowly add the reaction solution obtained in step (b) dropwise to 40kg of 22% ammonia wa...

Embodiment 2

[0018] This embodiment provides a method for synthesizing p-aminobenzenesulfonamide, which sequentially includes the following steps:

[0019] (A) Add 15 mol of chlorosulfonic acid to the reaction kettle, control the temperature to 50 ℃, and continuously add 10 mol of acetanilide (add it slowly according to the conventional method, and complete the addition within 1.5 to 2 hours), then heat up to 60 ℃ and react for 1 hour to obtain p-acetamido The first mixture of benzenesulfonic acid and acetaminobenzenesulfonic acid chloride,

[0020] (B) Add 1 mol of dichloroethane to the first mixture, increase the temperature to 75°C, and then drop in 0.05 mol DMF and 5 mol SOCl 2 The mixture of acetamidobenzene sulfonic acid is converted into acetaminobenzene sulfonyl chloride by dropping it in according to the conventional method and adding it in 0.5~1h.

[0021] (C) Control the temperature of the reactor at 25°C, slowly add the reaction solution obtained in step (b) dropwise to 32kg of ammoni...

Embodiment 3

[0024] This embodiment provides a method for synthesizing p-aminobenzenesulfonamide, which sequentially includes the following steps:

[0025] (A) Add 20mol of chlorosulfonic acid to the reaction kettle, control the temperature at 45℃, and continuously add 10mol of acetanilide (add it slowly according to the conventional method, and complete the addition within 1.5~2h), then heat to 58℃ and react for 1.5h to obtain p-acetyl The first mixture of aminobenzenesulfonic acid and acetaminobenzenesulfonic acid chloride,

[0026] (B) Add 1.5 mol of dichloroethane to the first mixture, raise the temperature to 70°C, and then drop 0.2 mol of DMF and 5 mol of SOCl 2 The mixture of acetamidobenzene sulfonic acid is converted into acetaminobenzene sulfonyl chloride for 2h after adding dropwise according to the conventional method, within 0.5~1h;

[0027] (C) Control the temperature of the reactor at 20°C, slowly drop the reaction solution obtained in step (b) into 35kg of ammonia water with a mas...

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Abstract

The invention relates to a synthetic method of p-aminobenzenesulfonamide, which is characterized by successively includes the following steps: (a) adding chlorosulfonic acid into a reaction kettle, controlling the temperature to be 40-50 DEG C, adding acetanilide, increasing the temperature to 55-60 DEG C and performing a reaction for 1-2 h to obtain a first mixture; (b) adding dichloroethane, increasing the temperature to 65-75 DEG C, dropwisely adding a catalyst and SOCl2, and continuously performing the reaction for 1-3 h; (c) controlling the temperature in the reaction kettle to be 15-20 DEG C, dropwisely adding the mixed liquid obtained in the step (b) into ammonia water being 22-25% in mass concentration, stirring the liquid for 0.5-1 h, increasing the temperature to 40-42 DEG C and continuously performing the reaction with stirring for 1-2 h, and filtering the liquid to obtain a crude product of the p-aminobenzenesulfonamide; and (d) adding the crude product in a hydrolysis kettle, adding a NaOH solution being 20-30% in mass concentration, heating the mixture to 90-95 DEG C to perform reflux hydrolysis for 2-3 h, adding an acid solution to regulate the pH value to 6.5-6.7, performing centrifugation, and drying a filter residue to obtain the p-aminobenzenesulfonamide. In the method, the addition quantities of the reactants are accurately controlled so that the use amount of the chlorosulfonic acid is reduced. The method is reduced in cost and is increased in yield and purity of the product.

Description

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Claims

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Application Information

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Owner SUZHOU WUGAN PHARMA
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