2,3-Dihydroxynaphthalene Property

Melting point:

161-165 °C (lit.) 162-164 °C

Boiling point:

246.06°C (rough estimate)

Density 

1.0924 (rough estimate)

vapor pressure 

0.8 hPa (149 °C)

refractive index 

1.5178 (estimate)

Flash point:

175 °C

storage temp. 

Store below +30°C.

solubility 

4g/l

form 

Powder

pka

9.10±0.40(Predicted)

color 

White to pinkish to beige-grayish

PH

6 (1g/l, H2O, 20℃)

Water Solubility 

slightly soluble

BRN 

742375

CAS DataBase Reference

92-44-4(CAS DataBase Reference)

NIST Chemistry Reference

2,3-Naphthalenediol(92-44-4)

EPA Substance Registry System

2,3-Naphthalenediol (92-44-4)

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-37/39

WGK Germany 

3

RTECS 

QJ4750000

F 

10-23

Autoignition Temperature

>330 °C

TSCA 

Yes

HS Code 

29072900

Toxicity

LD50 orally in Rabbit: 970 mg/kg

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H302Harmful if swallowed

H318Causes serious eye damage

Precautionary statements

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P270Do not eat, drink or smoke when using this product.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P301+P312IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P501Dispose of contents/container to..…

2,3-Dihydroxynaphthalene Chemical Properties,Usage,Production

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.