4-Nitrophenol-2-sulfonic acid

N.C6H3(0H).S03Na, mw 241.16, N 5.8%, orange-red crysts. Can be prepd by treating the product obtained on sulfonation of phenol with Na nitrate and an excess of sulfuric acid. This salt, which is a mixt of Na o- and p-nitrophenol-sulfonates, was patented in 1911 by A. Voight for use in expl mixts such as Na nitrophenol-sulfonate 22.5 to 25, K or Na nitrate 45 to 65,... 

Whole cell OPH activity was measured by following the increase in absorbancy of p-nitrophenol from the hydrolysis of substrate (0.1 mM Paraoxon) at 400 nm (sm = 17,000 M cm ). Samples of culture (1 ml) were centrifuged at 10,000 g and 4 C for 5 min. The cells were washed, resuspended with distilled water, and 100 pi was added to an assay mixture containing 400 pi 250 mM CHES [2-(N-cyclohexylamino)ethane-sulfonic acid] buffer, pH 9.0, 100 pi 1 mM Paraoxon, and 400 pi distilled water. One unit of OPH activity was defined as pmoles Paraoxon hydrolyzed per min. Each value and error bar represents the mean of two independent experiments and its standard deviation. 

Succinic acid, see 2-Chlorophenol. Cyclopentene, Maleic hvdrazide. 4-Nitrophenol, Phenol, 2,4.5-T Succinic semialdehyde, see Pyridine Succinyl-CoA, see Cyclohexane Sulfanilamide, see Asulam Sulfanilic acid, see Asulam Sulfonamide, see Prosulfuron Sulfonic acid, see Prosulfuron Sulfur, see Aldicarb. Benzene, Captan. Ferbam. 

In the synthesis of the symmetrical 1 2 cobalt azomethine complex 19 [41043-60-1] [31], a mixture of 2-amino-6-nitrophenol-4-sulfonic acid and salicylaldehyde is heated to boiling in sodium acetate solution. The suspension is cooled and mixed first with CoCl2-6H20 and then with 30% H202. The resulting solution is salted out with NaCl and KC1. The dye yields exceptionally lightfast yellow colors on wool and polyamides. 

Replacement of the diazo group by hydrogen has been reported for a number of diazo oxides. For example, the diazo oxide from 2-nitro-4-aminophenol yields o-nitrophenol in 53% yield,42 - 43 and that from 1-amino-2-hydroxy-6-bromonaphthalene-4-sulfonic acid gives XV in approximately 50% yield.44... 

Dibromo-4-nitrophenol has been prepared by the nitration of 2,6-dibromophenol1 or of dibromophenol sulfonic acid,2 and by the action of nitric acid on 2,6-dibromo-4-nitroso-phenol3 or on 2,4,6-tribromophenol.4 It has been obtained from the corresponding ethyl ether 5 and by the action of bromine on />-nitrosophenol,6 4,6-dibromo-2-nitrophenol,7 5-nitro-2-hydroxy-benzoic acid,8 and 5-nitro-2-hydroxybenzenesulfonic acid.9 The dibromination of />-nitrophenol I0>13 has been carried out in sulfuric acid solution 11 and in the presence of aluminum chloride.12 The method described here is essentially that of M"hlau and Uhlmann.13... 

Reduction of 2-nitrochIorobenzene-4-sulfonic acid gives o-chlorometanilic acid which is used in making azo dyes. The real technical value of nitrochlorobenzene-sulfonic acid, however, lies in the ability of its chlorine atom to be replaced by various groups. For example, o-nitrophenol-p-sulfonic acid is obtained by treatment wiui sodium hydroxide, and this product, on reduction, yields o-aminophenol-p-sulfonic acid. An ogously, nitrochlorobenzenesulfonic acid gives o-nitroanisole-p-sulfonic acid by treatment with alcoholic methanol, and from this is obtained o-anisidine-p-sulfonic acid. The action of ammonia on nitrochlorobenzenesulfonic acid produces o-nitroaniline-p>sulfonic acid aniline and its derivatives produce o-nitrodiphenylamine-p Sulfonic acids (cf. Table II). 

Many commercial dyes contain one or more sulfonic acid groups to confer water solubility to the dye and assist in binding the dye to the polar fibres in the textile (cotton, nylon, silk, wool, etc.). An example is Congo Red (12) (Figure 3). This is red in alkaline solution thus, the sodium salt will dye cotton red, but it is very sensitive to acids and on acidification the colour changes from red to blue, and so this compound is also used as a type of indicator. Vat dyes, known as sulfur dyes, can be prepared by heating various organic compounds, e.g. amines, aminophenols, and nitrophenols, with sodium polysulfide. 

Sodium 3-nitro-4-hydroxybenzenesulfonate was prepared from 2-nitrophenol and chlorosulfonic acid by the method of Gnehm and Krecht (13). The sulfonic acid was converted to the sodium saltlSy precipitation from saturated sodium chloride solution. 

The following compounds are used as inhibitors in acid solutions amines, amino-imidazolines, amino- and nitrophenols, aminotriazole, aldehydes, bezothiazol, dibenzyl sulfoxide, dithiophos-phoric acids, guanidine derivatives, ureas, phosphonium salts, sulfonium salts, sulfonic acids, thio-ethers, thioureas, and thiocarbanoyl disulfides. Amino alcohols, aminobenzimidazole, benzoates, quinoline derivatives, cinnamates, fatty amines, polyether amines, silicates, and triazoles are used as inhibitors in neutral or weakly alkaline solutions, while for strongly alkaline solutions, aldehydes and fatty amines are used. 

Several methods have been described that employ a special substrate designed to give a colored end product after hydrolysis, or one that can be easily converted to a colored product. The p-nitrophenol liberated from the hydrolysis of p-nitrophenyl butyrate is readily measured directly (191). y8-Naphthyl laurate has been used as a substrate for serum lipase. The )8-naphfhol hberated is combined with tetrazotized di-o-anisidine to give a pigment (211, 212). Several esters of 2-naphthol-6-sulfonic acid have been used as substrates for milk lipase. The naphthol-sulfonic acid liberated is determined by the Folin-Ciocalteu reagent (213). 

Amino-6-nitro-1-phenol-4-sulfonic acid CAS 96-93-5 EINECS/ELINCS 202-546-7 Synonyms 3-Amino-4-hydroxy-5-nitrobenzenesulfonic acid 2-Amino-6-nitrophenol-4-sulfonic acid Empirical C6H6N2O6S... 

Synonyms 3-Amino-2-hydroxy-5-nitrobenzene sulfonic acid 6-Amino-4-nitrophenol-2-sulfonic acid 2-Hydroxy-5-nitrometanilic acid... 

Amino-4-nitrophenol-2-sulfonic acid. See 6-Amino-4-nitro-1-phenol-2-sulfonic acid [8-[(4-Am i no-3-nitrophenyl) azo]-7-hydroxy-2-naphthyl] trimethylammonium chloride 8-[(4-Amino-3-nitrophenyl) azo]-7-hydroxy-N,N,N-trimethyl-2-naphthalenaminium chloride. See Basic brown 17... 

Kosover, V. Fabian, J. R. Lippai, I. Benage, B. Abruscato, G. J. Aromatic sulfonic acids, amines, and nitrophenols in combination with nitroxyl radical-containing compounds or c-nitrosanilines as polymerization inhibitors. U.S. Pat. Appl. Publ. US 2006122341, 2006 Chem. Abstr. 2006,145, 28383. 

It has been proposed that 8-aminodcoxyguanosinc is formed from the nitronate tautomer of 2-nitropropane either by base nitrosation followed by reduction, or via an enzyme-mediated conversion of the nitronate anion to hydroxyiam ine-O-sulfonate or acetate, which yields the highly reactive nitrenium ion NHj (Sodum et al., 1993). Sodum et al. (1994) have provided evidence for the activation of 2-nitropropane to an aminating species by rat liver aryl sulfotransferase in vitro and in vivo. Pretreatment of rats with the aryl sulfotransferase inhibitors pentachlorophenol or 2,6-dichloro-4-nitrophenol significantly decreased the levels of nucleic acid modifications produced in the liver by 2-nitropropane treatment. Partially purified rat liver aryl sulfotransferase activated 2-nitropropane and its nitronate at neutral pH to a reactive species that aminated guanosine at the position. This activation was dependent on the presence of the enzyme, its specific cofactor adenosine 3 -phosphate 5 -phosphosulfate, and mercaptoethanol. It was inhibited... 

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