Hydroxy-naphthalene sulfonates

Amino-3-hydroxy-7-nitro-l-naphthalene-sulfonic acid [6259-63-8]... 

Some green algae are able to use aromatic sulfonic acids (Figure 2.4a) (Soeder et al. 1987) and aliphatic sulfonic acids (Figure 2.4b) (Biedlingmeier and Schmidt 1983) as sources of sulfur. Cultures of Scenedesmus obliquus under conditions of sulfate limitation metabolized naphthalene-l-sulfonate to l-hydroxy-naphthalene-2-sulfonate and the gluco-side of naphth-l-ol (Kneifel et al. 1997). These results are consistent with formation of a 1,2-epoxide followed by an NIH shift. 

Lower-sulfonated subsidiary colors of sunset yellow, among them 5-(phenylazo)-6-hydroxy-naphthalene-2-sulfonic acid (ANSC) and 4-[(2-hydroxynaphthalene-l-yl)azo]benzenesulfonic acid (BNSC), were determined by reverse-phase HPLC using Novapak Cl 8 and gradient elution with a water-tetrahydrofuran solvent system buffered with ammonium acetate (192). 

Heterocycles are known to have O—S, S—N, and O—N bonds. The cyclization of peri-hydroxy and peri-amino-substituted naphthalene sulfonic acids gives rise to 1,8-naphthosultone 246 and 1,8-naphthosultam 247, respectively (33MI2 63MI1). On gas phase photolysis of naphtho[/>c]-... 

A particularly important class of coupling components are the aminohydroxy-naphthalenesulfonic acids. Appropriate variation of the disazo component permits the development of shades ranging from orange to black. Orange and scarlet are achieved with I-acid (6-amino-l-hydroxy-naphthalene-3-sulfonic acid) and y-acid (7-amino-1-hydroxynaphthaIcne-3-sulfonic acid), whereas H-acid (8-amino-l-hydroxynaphthalene-3,6-disulfonic acid) and K-acid (8-amino-l-hydroxy-naphthalene-3,5-disulfonic acid) derivatives are useful for red to bluish-red hues. Extremely lightfast red shades are also accessible with disazo dyes ( brown dyes ). For chemical structures see Section 3.1.5). 

Alkaline glucose converts the diazonium salts of l-amino-2-hydroxy-naphthalene-4-sulfonic acid and its halogen, nitro, carboxyl, or sulfonic acid derivatives into the corresponding 2-hydroxynaphthalene-4-sul-fonic acids.126 According to this patent, the yields are nearly quantitative. 

The raw materials used to synthesize organic dyes are commonly referred to as dye intermediates. Largely, they are derivatives of aromatic compounds obtained from coal tar mixtures. The majority of these derivatives are benzene, naphthalene, and anthracene based compounds. This section provides an overview of the chemical reactions used to prepare the key intermediates employed in dye synthesis. In this regard, emphasis is placed on halogenated, aminated, hydroxy-lated, sulfonated, and alkylated derivatives of benzene, naphthalene, and anthraquinone. 

Disodium 6-Hydroxy-5-[(2-methoxy-5-methyl-4-sulfophenyl) azo]-8-(2-methoxy-5-methyl-4-sulfophenoxy)-2-naphthalene-sulfonic Acid Not more than 1.0%. 

Naphthol Yellow S (citronin A, flavianic acid sodium salt, 8-hydroxy-5,7-dinitro-2-naphthalene sulfonic acid disodium salt) [846-70-8] M 358.2, m dec on heating. Greenish yellow powder soluble in H2O. The free sulfonic acid can be recrystd from dil HCl (m 150°) or AcOH-EtOAc (m 148-149.5°). The disodium salt is then obtained by dissolving the acid in two equivalents of aqueous NaOH... 

Naphthalenediol is obtained in 67% yield when sodium 3-hydroxy-l-naphthalene-sulfonate (6.3 g) is heated with KOH (13.4 g) and water (3 ml) at 190-2000.652 Only 5% of the diol is obtained if the mixture is fused at 250-260°. 

The site at which the sulfo group appears in / -naphthol depends very markedly on the temperature. At low temperatures 2-hydroxy-1-naphthalene-sulfonic acid is obtained 150 at higher temperatures or when an excess of sulfuric acid is used, migration of the sulfo group leads to 7-hydroxy- 1-naph-thalenesulfonic acid (croceic acid), and finally at 110° almost exclusively to 7-hydroxy-2-naphthalenesulfonic acid (Schaffer acid). Further treatment with an excess of sulfuric acid leads to / -naphthol-di- and -tri-sulfonic acids, which are important for the dyestuffs industry but which will not be discussed in detail... 

Acid red 14 [4-hydroxy-3,4-azodi-l-naphthalene-sulfonic acid disodium salt disodium 2-(4-sulfo-1 -naphthyl-azo)-1 -naphthol-4-sulfonate, chromotrope FB, azorubin. Cl 14720] [3567-69-9]... 

Acetylamino-2-sulfophenylazo)-6-amino-4-hydroxy naphthalene-2-sulfonic acid, disodium salt. See Acid red 37... 

CAS 1658-56-6 EINECS/ELINCS 216-760-3 Synonyms Cl 15620 Ext. D C Red. no. 8 Fast red A 4-(2-Hydroxynaphthalen-1-ylazo) naphthalene-1-sulfonic acid, sodium salt 4-((2-Hydroxy-1 -naphthalenyl) azo)-1 -naphthalene sulfonic acid sodium salt 1-Naphthalenesulfonic acid, 4-((2-hydroxy-1-naphthalenyl) azo)-, monosodium salt Red no. 506 Rocceline Roccelline Solid red A Classification Azobenzene Empiricai C2oHi4N2Na04S Properties M.w. 401.41 m.p. 280 C Toxicoiogy Mutagen TSCA listed Storage Store in cool, dry place keep container closed when not in use... 

Hydroxynaphthalen-1 -ylazo) naphthalene-1 -sulfonic acid, sodium salt 4-((2-Hydroxy-1-naphthalenyl) azo)-1-naphthalene sulfonic acid... 

Naphthalenesulfonic acid, 6-amino-4-hydroxy-5-((2-(trifluoromethyl) phenyl) azo)-, monosodium salt. See Acid red 337 Naphthalenesulfonic acid, bis-(l-methylethyl)-, sodium salt. See Sodium isopropyl naphthalene sulfonate... 

Mahmoud, M.E. Soayed, A.A. Hafez, O J. Selective sohd phase extraction and pre-concentration of heavy metals from seawater by physicahy and chemicahy immobilized 4-amino-3-hydroxy-2-(2-chlorobenzene)-azo-l-naphthalene sulfonic acid silica gel. Microchim. Acta 2003,143 (1), 165. 

In our laboratory, this method was appUed to the purification of food mono-azo dyes. Amaranth, New Coccine, and Sunset Yellow FCF were purified at 99.7%, 99.5%, and 99.3%, respectively, from 1-23 g of commercial dyes. Continued research has led to the purification of impurities present in commercial Sunset Yellow FCF that include RS-SA (trisodium salt of 3-hydroxy-4-[sulfophenyl] azo-2,7-naphthalene disulfonic acid), GS-S A (1 -[4-sulfophenyl]azo)-2-naphthol-6,8-disulfonic acid), DONS (disodium salt of 6,6 -oxybis-2-naphthalene sulfonic acid), and 2N-SA (sodium salt of 4-[(2-hydroxy-l-naphthalenyl)azo]benzenesulfonic add). The method successfully isolated GS-SA from Sunset Yellow FCF. " ... 

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