2,3-Dihydroxynaphthalene

Chemical Properties

Off white to redish white powder. 2,3-Naphthalenediol [92-44-4], mp 161℃, gives a dark blue color with iron(III) chloride; is aminated to 2- amino-3-naphthol at 140℃ and 2,3-naphthalenediamine at 240℃; and couples with diazotized anilines in the 1- or 1,4-positions.

Uses

2,3-Naphthalenediol is used in cosmetics asa component of oxidative hair dye. It is usedat a concentration of <0.1%.

Uses

2,3-Dihydroxynaphthalene is used in making dyes, pigments, fluorescent whiteners, tanning agents, antioxidants, and antiseptics.

Uses

2,3-Dihydroxynaphthalene may be used in the following studies:

• Construction of dinaphtho[2,1-b;2′,3′-d]furan-6-ol, via dehydration reaction in the presence of strong acid.
• As fused ring catecholate type ligand for the surface modification of nanocrystalline TiO₂ particles.
• As adsorptive and competing ligand during the chemical speciation of iron in seawater by cathodic stripping voltammetry.
• Synthesis of cyclotriphosphazene derivatives, used as non-halogen flame retardants

Definition

ChEBI: Naphthalene-2,3-diol is a naphthalenediol.

General Description

2,3-Dihydroxynaphthalene is a polyhydroxy phenol. It is an aromatic dihydroxy compound having hydroxyl groups at ortho positions. Its reaction with molybdenum(VI) complexes has been reported. The asymmetric oxidative coupling polymerization of 2,3-dihydroxynaphthalene using the Cu(I)-bisoxazoline complex as catalyst has been reported to afford poly(2,3-dihydroxy-1,4-naphthylene), having a continuous 1,1′-bi-2-naphthol main chain structure. The nitrodisplacement reaction between nitrophthalodinitriles and 2,3-dihydroxynaphthalene has been investigated.

Health Hazard

2,3-Naphthalenediol shows low toxicity andmild irritant actions on the skin and eyes. Theoral LD50 value for rats of a 5% solutionin propylene glycol may be on the orderof 675 mg/kg (calculated by the method ofWeil). The intravenous LD50 value for miceis 56 mg/kg. At 1% concentration, it causedslight eye irritation in female albino rabbitsand exhibited erythemal response in guineapigs. At the 0.1% level (concentration in hairdye), it had no reaction on human skin. Thiscompound was nonmutagenic in Salmonellatyphimurium strain tests.
There is very little information in the literatureon the toxicity of 2,3-naphthalenediol.Assessment by the CIR expert panel on thesafety of this compound as used in cosmeticshas been inconclusive (Cosmetic, Toiletryand Fragrance Association 1987b).

Synthesis

2,3-Dihydroxynaphthalene is prepared by caustic fusion of 3-hydroxynaphthalene-2,6-disulfonic acid followed by treatment with dilute sulfuric acid under pressure, or by acid desulfonation of 2,3-dihydroxynaphthalene-6-sulfonic acid.