8-Amino-l-naphthol

The role of N-sulfonyloxy arylamines as ultimate carcinogens appears to be limited. For N-hydroxy-2-naphthylamine, conversion by rat hepatic sulfotransferase to a N-sulfonyloxy metabolite results primarily in decomposition to 2-amino-l-naphthol and 1-sulfonyloxy-2-naphthylamine which are also major urinary metabolites and reaction with added nucleophiles is very low, which suggests an overall detoxification process (9,17). However, for 4-aminoazobenzene and N-hydroxy-AAF, which are potent hepatocarcinogens in the newborn mouse, evidence has been presented that strongly implicates their N-sulfonyloxy arylamine esters as ultimate hepatocarcinogens in this species (10,104). This includes the inhibition of arylamine-DNA adduct formation and tumorigenesis by the sulfotransferase inhibitor pentachlorophenol, the reduced tumor incidence in brachymorphic mice that are deficient in PAPS biosynthesis (10,115), and the relatively low O-acetyltransferase activity of mouse liver for N-hydroxy-4-aminoazobenzene and N-OH-AF (7,114,115). 

Technologically, the most important examples of such couplers are 1-naphthylamine, 1-naphthol, and sulfonic acid derivatives of 1-naphthol (Fig. 2). Of great importance in the dyestuff industry are derivatives of l-naphthol-3-sulfonic acid, such as H-acid (8-amino-l-naphthol-3,6-disulfonic acid [90-20-0])... 

Of far greater importance are the sulphonated aminonaphthols, in which the versatility conferred by the presence of both an amino and a hydroxy group makes them among the most important group of azo intermediates. Three are outstanding, namely, 6-amino-l-naphthol-3-sulphonic acid (4.16 J acid), 7-amino-l-naphthol-3-sulphonic acid (4-17 y acid) and H acid (4.2), which couple under the relevant conditions of pH at the arrowed positions. 

Probtem 18.63 Synthesize from naphthalene and any other reagents (a) naphthionic acid (4-amino-l-naphthalenesulfonic acid), (b) 4-amino-l-naphthol, (c) 1,3-dinitronaphthalene, (d) 1,4-diaminonaphthalene, (e) 1,2-dinitronaphthalene. Do not repeat the synthesis of any compound. ... 

Amino-2-methyl-l-naphthol hydrochloride [130-24-5] M 209.6, m 283°(dec). Crystd from dilute HC1. 

Heating o-nitrosophenols with hydroxylamine is reported to give furazans, naphtho[l,2-c]furazan (95) being formed from both l-nitroso-2-naphthol and 2-nitroso-l-naphthol, presumably by oximation of the tautomeric o-naphthoquinone monooximes and subsequent dehydration. Compound (95) has also been prepared by oxidation, using alkaline ferri-cyanide or hypochlorite, of l-amino-2-nitroso- and 2-amino-l-nitroso-naphthalene. This latter approach is suitable for heterocyclic fused furazans thus 4,6-diamino-5-nitrosopyrimidine is converted into the furazanopyrimidine (96) by oxidation with lead tetraacetate (71JOC3211). In a similar reaction alkaline hypochlorite oxidizes o-nitrosoacetaniiide to benzofurazan in quantitative yield. 

The small increase of the reaction rate for the 1-position (dotted line) at pH 9.5 to 10.0 reflects experimental results obtained by Ikeda et al. 255-257) paper these authors determined the relative rate constants for azo coupling reactions of 6-amino-l-naphthol-3-sulfonic acid (J-acid, 153) with 4-methyl- and 4-chlorobenzenediazonium ions in competitive experiments to the azo coupling reaction of l-naphthol-4-sulfonic acid at pH 5.5-9.1. The rate at the 2-position of J-acid, i.e. the reaction directed by the O -group, is 300-4000 times faster than that at the 5-position, which is directed by the amino group. These authors made two interesting observations ... 

As we found more recently , these orientation effects can be disguised by mixing effects of the type discussed in Section 4.2. In reactions of 3-trifluoromethyl-benzenediazonium ions with 7-amino-l-naphthol-3-sulfonic acid 154, rates and product ratios which would be predicted from Figure 3 are obtained only in very dilute solutions (<10 mol/1). In systems with higher concentrations of the reactants the product with the 3 -trifluoromethylphenylazo group in the 8-position is not only dominant in acidic solution, as expectal, but also up to pH 9. In this pH range also considerable amounts of bisazo product are obtained. These are observations which are typical for mixing eff ts observed in very fast reactions. With the unsubstituted benzenediazonium ions, a less reactive electrophile, however, rates and products are determined only by equilibria of the type of (70). 

BLUE 2B NB2B NCI-C54579 NIAGARA BLUE 2B NIPPON BLUE BB PARAMINE BLUE 2B PHENAMINE BLUE BB PHENO BLUE 2B PONTAMINE BLUE BB SODIUM DIPHENYL-4,4 -BIS-AZO-2 -8"-AMINO-l"-NAPHTHOL-3",6" DISULPHONATE TERTRODIRECT BLUE 2B VONDACEL BLUE 2B... 

The introduction of amino groups into phenols and ethers can be accomplished by the formation and reductive cleavage of their azo compounds. The diazotizing agent may be prepared from sulfanilic acid, and the reduction can be performed with sodium hydrosulfite. Excellent examples are found in the synthesis of l-amino-2-naphthol (85%) and 4-amino-l-naphthol (75%). ... 

Chicago acid. (l-amino-8-naphthol-2,4-disul-fonic acid 8-amino-l-naphthol-5,7-disulfonic acid SS acid 1,8,2,4-acid 2-sulfur acid). 

Amino-2-methyl-l-naphthol See Vitamin K5 in Miscellaneous Compounds , Chapter 6. 

Vitamin K5 (4-Amino-2-methyl-l-naphthol hydrochloride) [130-24-5] M 209.6, m 283"(dec), pKEst(i) 5.6 (NH2), pKj.jj(2) 10.4 (OH). Crystallise it from dilute HCl. [Sah Reel Trav Chim Pays-Bas 59 458 1941, Sah Reel Trav Chim Pays-Bas 60 373 1940, Veldstra Wiardi Reel Trav Chim Pays-Bas 61 547 1942, Veldstra Wiardi Reel Trav Chim Pays-Bas 62 75 1943, Beilstein 13 III 1921.]... 

The Colour Index (up to June 1991) lists 21 direct violets with disclosed chemical constitutions. Commercially important are Cl Direct Violet 9 [6227-14-1] (79) (Cl 27885) (sulfanilic acid coupled to cresidine followed by alkaline coupling to IV-phenyl J-acid) and Cl Direct Violet 66 [6798-05-4] (80) (Cl 29120) (a copper complex of 2-amino-l-phenol-4-sulfonamide (2 mol) coupled to 6,6,-iminobis- l-naphthol-3-sulfonic acid). 

Amanil blue 2BX[3,3 -((4,4 -biphenylylene) bis(azo)bis(5-amino-4-hydroxy-2,7-naphthalene disulfonic acid tetrasodium salt, sodium diphenyl-4,4 bis-azo-2, 8 -amino-l -naphthol-3, 6 -disulfonate, benzanil blue 2B, paramine blue 2B, Cl 22610] [2602-46-2] Amanil sky blue [3,3 -((3,3 -dimethoxy-4,4 -biphenylene)bis(azo))bis(5-amino-4-hydroxy)-2,7-naphthalenedisulfonic acid tetrasodium salt benzanil sky blue direct blue 5 Cl 24400] [2429-74-5]... 

DL-2-Amlno-l-(3-methoxyphenyl)propanol(3-methoxynorephedrine) 8-Amino-l-naphthol (C H ON)... 

Methyl-4-amino-l-naphthol hydrochloride (vitamin Ks), antibiotic properties of, VI, 36... 

New cellulose manbranes were recently prepared by the phase inversion method using a green solvent, the ionic liquid [BMIM][C1] [32], After functionalization with a synthetic ligand 2-(3-aminophenol)-6-(4-amino-l-naphthol)-4-chloro-5-triazine, these adsorptive membranes were evaluated for human immunoglobulin G (IgG) adsorption. The authors envisage that a change in the conditions and chemistry for membrane activation with the biomimetic ligand may improve the performance of the affinity cellulose membranes. 

Amino 8 - naphthol - 3 6-disulphonic Acid (1-Amino-l-ndphthoi-Z Q-disi hoiM aciA 2R Acid). 

---