ChemicalBook CAS DataBase List Aniline-2-sulfonic acid

Aniline-2-sulfonic acid synthesis

12synthesis methods

Product Name:Aniline-2-sulfonic acid
CAS Number:88-21-1
Molecular formula:C6H7NO3S
Molecular Weight:173.19

2-Aminobenzenesulfonic acid (Aniline-2-sulfonic acid) is obtained from 2-nitrothiophenol by boiling in a mixture of dioxane and water (ratio 20:1) for seven hours; the yield is 86.7% of theory. The acid can also be produced as follows: 2-chloronitrobenzene is reacted with sodium disulfide in aqueous alcoholic solution to form 2,2'-dinitrodiphenyl disulfide. After having been dissolved in a mixture of hydrochloric acid and nitric acid this is oxidized with chlorine to form 2-nitrobenze- nesulfonyl chloride, which is then hydrolyzed with soda solution and finally reduced with iron turnings. Alternatively 2,2'-dinitrodiphenyl disulfide can first be reduced to 2,2'- diaminodiphenyl disulfide and then oxidized with hydrogen peroxide in aqueous sulfuric acid to 2-aminobenzenesulfonic acid.
2,2'- Diamino-diphenyldisulfide can also be arrived at by alkaline hydrolysis of benzothiazole or mercaptobenzothiazole, followed by oxidation with hydrogen peroxide. The additional oxidation leading to 2-aminobenzenesulfonic acid can be performed in alkaline solution. Thus the synthesis starting from benzothiazole can be carried out exclusively in alkaline solution in a single reactor. Yield: 70%, based on benzothiazole.

62-53-3 Synthesis

62-53-3
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88-21-1
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Yield:88-21-1 99%

Reaction Conditions:

with sodium hydrogen sulfate;sulfuric acid at 200; for 19 h;Reagent/catalyst;Temperature;

Steps:

1 Synthesis of o- aminobenzenesulfonic acid
94 g of aniline,100 grams of concentrated sulfuric acid (concentration of 98% concentrated sulfuric acid)120 g of sodium bisulfate were added sequentiallyIn the dispenser,Dispersion for 1 hour,And then dispersed into a uniform material into the baking tray,Placed in a vacuum oven,Heated to 200 ° C,After 18 hours of incubation,The material was poured into 600 ml of water,And adding 1 gram of activated carbon,Heated to 80 ° C decolorization,After bleaching out liveCarbon,Stirring,Cooled to room temperature,crystallization,filter,168 g of a white solid was obtained,Content: 99%.

References:

Shenyang Chemical Research Institute Co., Ltd.;Yan, Shijie;Li, Fugang;Li, Wenxiao CN105481735, 2016, A Location in patent:Paragraph 0017; 0018; 0019; 0020

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