1- Naphthylamine-3,6,8-trisulfonic

Naphthylamine-3,6,8-trisulfonic add (Kodi acid) 211 ].-Amino-8-naphdiol-3,6-disulfonic add (H add). . 213... 

Derivation Fusion of a naphthylamine trisulfonic acid with sodium hydroxide. 

Sulfonation of l-naphthylamine-8-sulfonic acid with oleum gives, depending on the conditions, either the di- or trisulfonic acid of naphthylamine (as well as the naphthsultamdisulfonic acid ). Alkali fusion of these compounds yields the corresponding aminonaphtholsulfonic acids (III and IV), which are starting materials for wool and cotton dyes. 

To 800 grams of 15 per cent oleum is added, over a period of 10 minutes, 192 grams (1.0 mole) of finely powdered j3-naphthylamine sulfate which has been intimately mixed with 1 gram of anhydrous carbonate. The temperature should not be allowed to rise above 50°C. The reaction mixture is now tested for complete solubility in water and soda monosulfonation is usually complete in 15 minutes. The mixture is cooled to 40°, and 350 grams of 66 per cent oleum is added over a period of 15 minutes with continuous stirring. The sulfonation is continued for 1 day at 55°, then for an additional day at 85°. Under these conditions, the 2,5,7- and 2,1,5-naphthylaminedisulfonic acids, which are formed first, are converted to 2-naphthylamine-l,5,7-trisulfonic acid ... 

Alkali fusion of l-naphthylamine-3,6,8-trisulfonic acid yields H acid, the most important member of this series of intermediates in the dye industry. The preparation of H acid is a typical example of fusion reactions. 

Derivation (3-naphthylamine sulfate is sulfonated with 66% oleum, the filtrate yields 2-naphthyl-amine-l,5,7-trisulfonic acid. On reaction with dilute sulfuric acid at 125C, this yields 2-naphthylamine-5,7-disulfonic acid from this J acid is obtained on reaction with 58% sodium hydroxide solution at 200C and 210 psi. 

Naphthalenedisulfonic acid, 4-((4-anilino-5-sulfo-1-naphthyl) azo)-5-hydroxy-, trisodium salt 1-Naphthol-3,6-disulfonic acid-8-azo-4 -[N-phenyl-1 -naphthylamine]-8 -sulfonic acid trisodium salt Sodium anazolene Trisodium 4 -anilino-8-hydroxy-1,1 -azonaphthalene-3,6,5 -trisulfonate... 

D C Red No. 2 Fast red FD C Red No. 2 Food red 2 Food red 9 2-Hydroxy-1,r-azonaphthalene-3,6,4-trisulfonic acid trisodium salt 3-Hydroxy-4-[(4-sulfo-1-naphthalenyl) azo]-2,7-naphthalenedisulfonic acid trisodium salt 3-Hydroxy-4-((4-sulfo-1 -naphthyl) azo)-2,7-naphthalenedisulfonic acid, trisodium salt Naphthol red Naphthylamine red... 

Zou et al. [1560] separated 14 phenylamine- and naphthylaminesulfonic acids (e.g., 2-aminonaphthalene-4,6,8-trisulfonic acid, l,3 diamino-4-sulfonic acid, phenylamine-2-sulfonic acid, 6-chlorophenylamine-3-sulfonic acid, naphthylamine-7-sulfonic acid) in 30 min on a Cjg column (A = 254 nm). Baseline resolution was achieved using an aqueous 10 mM phsophate buffer pH 6.8 mobile phase. The capacity ctors for these and 10 additional compounds belonging to these classes of compounds were tabulated. 

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