Energy-saving and emission-reducing sulfanilamide synthesis method and sulfanilamide

A technology of aminobenzenesulfonamide and a synthesis method, which is applied in the preparation of sulfonic acid amide, the preparation of sulfonic acid, and organic chemistry, can solve the problems of affecting the reaction process, large discharge of waste water and waste gas, waste of raw materials, etc., and achieves reduction of impurity content, The effect of reducing emissions and environmental protection of the process

Inactive Publication Date: 2018-08-14
新乡市锦源化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, acetanilide is a common route as a raw material to synthesize p-aminobenzenesulfonamide, but in the prior art, because the chlorosulfonation step must be an equilibrium reaction in the synthesis, a large excess of chlorosulfonic acid must be used to improve the yield Reacted
The sulfonation process and the hydrolysis of chlorosulfonic acid will also produce a large amount of hydrogen chloride, which will affect the reaction process, waste raw materials and discharge a large amount of waste water and waste gas

Method used

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Examples

Experimental program
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Effect test

preparation example Construction

[0018] The invention provides an energy-saving and emission-reducing synthesis method of p-aminobenzenesulfonamide, which comprises performing sulfonation reaction with acetanilide on a mixture of chlorosulfonic acid and carbon tetrachloride for several times and degassing after each sulfonation reaction . The reaction solution after sulfonation is then subjected to chlorination reaction, amination reaction and hydrolysis reaction in sequence.

[0019] Due to the high viscosity of chlorosulfonic acid, carbon tetrachloride and chlorosulfonic acid are mixed and diluted to facilitate full contact between chlorosulfonic acid and acetanilide, so that the reaction speed is fast and the conversion rate is high, thereby reducing the consumption of chlorosulfonic acid.

[0020] The mixture of carbon tetrachloride and chlorosulfonic acid has a good dilution effect and avoids the participation of organic solvents in the reaction. In some specific embodiments of the present invention, th...

Embodiment 1

[0048] A kind of synthetic method of the sulfanilamide of energy saving and emission reduction, comprising:

[0049] Prepare raw materials according to the molar ratio of chlorosulfonic acid: acetanilide: thionyl chloride: phosphorus pentachloride is 3:1:1:0.6. After mixing chlorosulfonic acid and carbon tetrachloride in a volume ratio of 1:1, they are divided into a first raw material, a second raw material and a third raw material according to a mass ratio of 2:3:1.

[0050] In the presence of phosphorus pentoxide, acetanilide is mixed with the first raw material, heated to 65-70° C. for sulfonation reaction for 20 minutes. Fill the reaction solution with an inert gas preheated to 80-90°C at a rate of 0.4L / min per liter of solution, and pump at an initial pumping speed of 0.6L / min per liter of solution, and the pumping speed increases every 6 minutes 0.03L / min per liter of solution, degassing for 35min to obtain the first mixed solution.

[0051] Mix the first mixed soluti...

Embodiment 2

[0057] A kind of synthetic method of the sulfanilamide of energy saving and emission reduction, comprising:

[0058] Prepare raw materials according to the molar ratio of chlorosulfonic acid: acetanilide: thionyl chloride: phosphorus pentachloride is 2.75:1:1:0.6. After mixing chlorosulfonic acid and carbon tetrachloride at a volume ratio of 1:1.2, they are divided into a first raw material, a second raw material and a third raw material according to a mass ratio of 1.5:3:1.

[0059] In the presence of phosphorus pentoxide, acetanilide is mixed with the first raw material, heated to 65-70° C. for sulfonation reaction for 15 minutes. Fill the reaction solution with an inert gas preheated to 80-90°C at a rate of 0.6L / min per liter of solution, and pump at an initial pumping speed of 0.6L / min per liter of solution, and the pumping speed increases every 6 minutes 0.04L / min per liter of solution, degassing for 30min to obtain the first mixed solution.

[0060] Mix the first mixed...

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Abstract

The invention relates to an energy-saving and emission-reducing sulfanilamide synthesis method and sulfanilamide, and belongs to the field of sulfanilamide synthesis. The synthesis method comprises the steps of with existence of phosphorus pentoxide, carrying out sulfonation reaction on a mixture of chlorosulfonic acid and carbon tetrachloride and acetanilide for multiple times, and degassing after sulfonation reaction every time; sequentially carrying out chlorination reaction, ammonization reaction and hydrolysis reaction. The molar ratio of chlorosulfonic acid to acetanilide is (2.75 to 3.25):1, and the volume ratio of chlorosulfonic acid to carbon tetrachloride is 1:(1.0 to 1.2). Each degassing operation is characterized by filling an inert gas into a reaction liquid at the speed of 0.3 to 0.5L/min per litter of solution, and extracting the air at the speed of 0.6 to 1.0L/min per litter of solution. The raw materials are thoroughly reacted, the dosage of the chlorosulfonic acid isless, the product yield is high, hydrogen chloride is fully recovered, and the discharge amount is reduced. The sulfanilamide prepared through the synthesis method is environmental-friendly in process, high in purity and low in cost.

Description

technical field [0001] The invention relates to the field of synthesis of p-aminobenzenesulfonic acid, and in particular to an energy-saving and emission-reducing synthesis method of p-aminobenzenesulfonamide and p-aminobenzenesulfonamide. Background technique [0002] In addition to being used to prepare crystalline sulfonamide for external anti-inflammation, p-aminobenzenesulfonamide can also be used to synthesize other sulfa drugs such as sulfamidine, sulfamethoxazine, sulfamethazine, etc. It is an important medicine and intermediate. [0003] At present, acetanilide is a common route as a raw material to synthesize p-aminobenzenesulfonamide, but in the prior art, because the chlorosulfonation step must be an equilibrium reaction in the synthesis, a large excess of chlorosulfonic acid must be used to improve the yield Reacted. The sulfonation process and the hydrolysis of chlorosulfonic acid will also produce a large amount of hydrogen chloride, which will affect the rea...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C303/36C07C311/39
CPCC07C303/08C07C303/36C07C311/39C07C309/88
Inventor 蔡红新樊明伟闫玲玲王书擘王元
Owner 新乡市锦源化工有限公司
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