4- Aminobenzenesulfonic acid

Substitution of various groups by amino or hydroxyl functions is industrially unimportant for the production of 2- and 4-aminophenol, but this type of reaction is used for the synthesis of 2- and 4-aminophenol derivatives. However, 3-aminophenol caimot be obtained easily by reduction. It is made by the reaction of 3-aminobenzenesulfonic acid [121 -47-1] with sodium hydroxide under fusion conditions (5—6 h 240—245°C). The product is purified by vacuum distillation (25). 

Metanilic acid (3-aminobenzenesulfonic acid) [121-47-1] M 173.2, m <300 (dec), pK from water (as the hydrate), under CO2 in a semi-darkened room. (The soln is photosensitive.) Dried over 90% H2SO4 in a vac desiccator. 

Dipping solution 1 Dissolve 500 mg 4-aminobenzenesulfonic acid and 150 mg 8-hydroxyquinoline in 100 ml of a mixture of acetone -diethyl ether — water (12 + 12 + 1). This solution is stable for several months. It should be topped up with diethyl ether from time to time to make up for evaporation losses. 

Nitrates and nitrites are first reduced to nitrosyl chloride with thionyl chloride. The volatile nitrosyl chloride then reacts with 4-aminobenzenesulfonic acid to yield a diazonium salt that then couples with 8-hydroxyquinoline to form a colored azo compound. Hence, the coupling reagent is applied to the chromatogram first. 

Aminobenzenesulfonic acid and 3-aminobenzenesulfonyl chloride failed to react with EMME (77JMC1001). (Substituted phenylamino)meth-ylenemalonates (48) were prepared in the reaction of 2-(5-amino-2-alkoxyphenyl)-8-azapurin-6-ones and EMME at 140°C (78GEP2747199 82SZP627755). 

Fig. 23 ESR spectra of Cu2Cr/aniline sulfonic acid derivatives after a thermal treatment at 200 °C for 4h in air recorded at 105 K with a sweep width of a 6500 G b 150 G. H(I) o-aminobenzenesulfonic acid H(I) m-aminobenzenesulfonic acid H(III) ...

Problem 21.9 (a) Why does sulfanilic (p-aminobenzenesulfonic) acid exist as a dipolar ion, while p-aminobenzoic acid does not (b) Why is sulfanilic acid soluble in bases but not in acids -4... 

A reactor charged with 4,4 -diphenylether-dicarboxylic acid, hydrazinesulfate, and polyphosphoric acid were mixed and reacted for 1 hour at 160°C and then further heated to 180°C. This mixture was then treated with 4-aminobenzenesulfonic acid and heated for an additional 2 hours. The molar solubility ratio of polyphosphoric acid/hydrazinesulfate and the molar monomer ratio ofhydrazinesulfatc/4,4 -dipheny-lether-dicarboxylic acid were kept constant at 10 and 1.2, respectively. The mixture was further treated with sufficient 4-aminobenzenesulfonic acid so that the molar ratio of in situ formed polyhydrazide was maintained at 1 1. After heating was stopped, the mixture was poured into warm water containing 5 wt% sodium hydroxide solution and a dark blue fiber obtained. The fiber was washed in distilled water and then dried in a vacuum furnace for 48 hours at 100°C. The dried material had a nitrogen/carbon ratio of 0.174 and a sulfur/carbon ratio of 0.058. The product had an Mw of... 

Preparation of 2-aminobenzenesulfonic acid phenyl ester graft copolymer... 

The step 2 product (0.40 g) and 2-aminobenzenesulfonic acid phenyl ester (0.53 g) were charged into a flask and then treated with 15.0 ml of pyridine and 1.10 ml of triphenyl phosphite and heated for 6 hours at 120°C. The solution was then precipitated in 150 ml of ethanol and washed with 1 M hydrochloric acid for one day and then stirred in water for one day. The material was isolated, dried, and 0.34 g of product isolated having an Mn of 11,300 Da and an Mw of 16,800 Da containing 8 mol% amide. 

Which of the following acids would be most suitable for preparing a buffer of pH 3.10 (i) hydrogen peroxide (ii) propanoic acid (iii) cyanoacetic acid (iv) 4-aminobenzenesulfonic acid ... 

Monoazo Yellow Salts. Several monoazo yellow salts have gained popularity since the 200°C temperature restriction on the use of diarylide yellows has been imposed. One is Pigment Yellow 168 [71832-85-4], the calcium salt of diazotized 3-nitro-4-aminobenzenesulfonic acid coupled with acetoaceto-2-chloroanilide. It provides a clean, somewhat greenish yellow color which shows good migration resistance but relatively poor tinctorial strength. It is used in polyethylene and inexpensive industrial finishes where the durability requirements are not high. 

Aminobenzenesulfonic acid, 16, 55 -Aminobenzoic acid, 13, 54 7-Aminobdiyeic acid, 17, 4 -AMINO-isO-BUTYR7C ACID, 11, 4 c-Aminocaproic ACID, 17, 7 2-Aminoethanesulfonic acid, 10, 98... 

The influence of the sulfonic acid group upon the course of ethanol deaminations somewhat resembles that of the methyl group. Thus, o-aminobenzenesulfonic acid gives only the ether 18 the meta isomer yields a mixture of m-ethoxybenzenesulfonic acid and benzenesulfonic acid (the ether predominates) 18> 19 and from p-aminobenzenesulfonic acid the only product isolated is benzenesulfonic acid.20... 

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