1- -2-hydroxynaphthalene

Naphthalenol. 2-Naphthol or p-naphthol or 2-hydroxynaphthalene/7i3 -/5 -i7 melts at 122°C and boils at 295°C, and forms colorless crystals of characteristic, phenoHc odor which darken on exposure to air or light. 2-Naphthol [135-19-3] is manufactured by fusion of sodium 2-naphthalenesulfonate with sodium hydroxide at ca 325°C, acidification of the drowned fusion mass which is quenched ia water, isolation and water-washing of the 2-naphthalenol, and vacuum distillation and flaking of the product. A continuous process of this type has been patented (69). The high sulfate content ia the primary effluent from 2-naphthol production is greatiy reduced ia modem production plants by the recovery of sodium sulfate. 

Naphthalenediol. This diol is prepared by the alkah fusion of 2-hydroxynaphthalene-6-sulfonic acid (Schaffer acid) at 290—295°C. Schaffer acid is usually produced by sulfonation of 2-naphthol with the addition of sodium sulfate at 85—105°C. This acid is also used as a coupling component in the production of a2o dyes such as Acid Black 26. 2,6-Naphthalenediol is used as a component in the manufacture of aromatic polyesters which, as is also tme of the corresponding amides, display Hquid crystal characteristics (52). 

Milling Red SWB l-[4-[4-[4-toluenesulfonyloxy]phenylazo](3,3 dimethyl-l,l -biphenyl)-4 -azo]-2-hydroxynaphthalene-6,8-disulfonic acid di-Na salt, Acid Red 114 [6459-94-5] M 830.8, m dec >250", Cl 23635, X,max 514nm. Salted out three times with sodium acetate, then repeatedly extracted with EtOH. [McGrew and Schneider J Am Chem Soc 72 2547 1950.] See Solochrome Violet R on p. 352 in Chapter 4. 

Discussion. An excellent method for the colorimetric determination of minute amounts of cobalt is based upon the soluble red complex salt formed when cobalt ions react with an aqueous solution of nitroso-R-salt (sodium 1-nitroso-2-hydroxynaphthalene-3,6-disulphonate). Three moles of the reagent combine with 1 mole of cobalt. 

Trimethyl-5-quinoxalinamine (152) gave 5-(2-hydroxynaphthalen-l-ylazo)-2,3,6-trimethylquinoxaline (153) substrate, 50% H3PO4 NaN02/ H20, 3°C, 1 h then p-naphthaol/2.5M NaOH dropwise, 3°C 94%). ... 

Under certain conditions, dry mixtures of lead chromate pigments with the azo-dyes l-(2. 4 -dimtrobenzcncazo)-2-hydroxynaphthalene (dinitroaniline orange) or l-(4 -chloro-2 -nitrobenzcncazo)-2-hydroxynaphthalene (chlorinated para-red) may lead to violent explosions dining mixing/blending operations. 

Successful decarboxylations where the substituents favor classic electrophilic aromatic substitution are known. Reaction of 2-hydroxy-l-naphthalenecarboxylic acid with mercuric acetate in cold acetic acid has been reported to give 2-hydroxynaphthalen-l-ylmercuric acetate [Eq. (71)] (84). Although the result probably requires reinvestigation,... 

Diazotization of 3-(4-aminophenyl)sydnones followed by reaction with 1- or 2-hydroxynaphthalene provides azo dyestuff materials <1998MI209>. A new type of reaction between 4-acetyl-3-arylsydnones and hydrazine yields substituted pyrrolidinones by a cycloaddition process involving loss of nitric oxide (Equation 20) <1999H(51)95, 2001AHC73>. 

Supplement to b) 2-Hydroxynaphthalene ((3-naphthol) is obtained from naphthalene. The reaction sequence includes sulfonation of the starting material at 150-160°C and subsequent alkaline baking of the intermediate sodium naphthalene-2-sulfonate with sodium hydroxide at 300 to 320°C for 6 to 8 hours. After the reac-... 

Hydroxy-3-naphthoic acid ( BONA or BON ) is prepared by heating the sodium salt of 2-hydroxynaphthalene with carbon dioxide in a pressure chamber at 240 to 250°C at a pressure of 15 bar (Kolbe synthesis). The reaction mixture is continuously agitated. Remaining 2-naphthol is separated and recycled ... 

The same chemistry is involved as with monoazo yellow pigments, except that (3-naphthol pigments are obtained by coupling with 2-hydroxynaphthalene ((3-naph-thol) instead of acetoacetarylides. They have the general chemical structure ... 

Bromophenylazo)-2-propyl hydroperoxide, 3156 l-(4-Chloro-2-nitrobenzeneazo)-2-hydroxynaphthalene, 3697... 

Dimethyl-4-(3,4-dimethyl-5-isoxazolylazo)isoxazolin-5-one, 3309 1 -(2,4-Dinitrobenzeneazo)-2-hydroxynaphthalene, 3702... 

Cultures of Bacillus sp. oxidized naphthalene to (-r)-fran5-l,2-dihydro-l,2-dihydroxy-naphthalene. In the presence of reduced nicotinamide adeninedinucleotide phosphate (NADPH2) and ferrous ions, a cell extract oxidized naphthalene to fra/ 5-naphthalenediol (Gibson, 1968). Hydroxylation by pure microbial cultures yielded an unidentified phenol, 1- and 2-hydroxynaphthalene (Smith and Rosazza, 1974). 

Hydroxynaphthalene< 1 -azo-4> benzenesulfonic acid (numbered azo bridge system) p-(2-Hydroxy-1 -naphthylazo)-benzenesulfonic acid (Chemical Abstracts, IUPAC Alternate Rule C-912.4). 

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