6-Hydroxynaphthalene-2-sulphonic acid Chemical Properties

Melting point:

>300 °C(lit.)

Boiling point:

335.63°C (rough estimate)

Density 

1.4643 (rough estimate)

refractive index 

1.5400 (estimate)

pka

0.41±0.40(Predicted)

CAS DataBase Reference

93-01-6(CAS DataBase Reference)

NIST Chemistry Reference

2-Naphthalenesulfonic acid, 6-hydroxy-(93-01-6)

EPA Substance Registry System

2-Naphthalenesulfonic acid, 6-hydroxy- (93-01-6)

Safety Information

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-36

WGK Germany 

3

MSDS

• Language:English Provider:SigmaAldrich

6-Hydroxynaphthalene-2-sulphonic acid Usage And Synthesis

Chemical Properties

2-Hydroxynaphthalene- 6 -sulfonic acid [93-01-6]. (6-hydroxynaphthalene-2-sulfonic acid), Schaeffer acid, C10H8O4S, Mr 224.23, is readily soluble in water, from which it can be recrystallized as the monohydrate (mp 129℃). The sodium salt is sparingly soluble in cold water (1.7 %) but forms a 30 % solution at 80℃. Coupling with diazo compounds results in substitution in the 1-position as does treatment with bromine, nitrous acid, or oleum. Fusion with potassium hydroxide gives 2,6-dihydroxynaphthalene, amination gives 2- aminonaphthalene-6-sulfonic acid, and sulfonation (20 % oleum, 25℃) results in 2-hydroxynaphthalene-1,6-disulfonic acid.

Uses

2-Hydroxynaphthalene-6-sulfonic acid is used as a coupling component for a wide range of azo dyes, e.g., C.I. Acid Orange 12, C.I. Food Yellow 3, and C.I. Food Orange 2. It is also used as an intermediate for more highly substituted dye components and synthetic tanning agents. The 1-nitroso derivative forms an iron complex (C.I. Acid Green 1) which was formerly used as a wool dye.

Preparation

2-Naphthol is added to a mixture of sulfuric acid and sodium sulfate, and the reaction is continued at 90 C for 12 h. After pouring the reaction mixture into water, the sodium salt of the product is precipitated by addition of salt and filtered at 60℃ to separate the isomers.

6-Hydroxynaphthalene-2-sulphonic acid(93-01-6)Related Product Information

• Phenmedipham
• 1,5-Naphthalenedisulfonic acid
• 2-Aminonaphthalene-1-sulfonic acid
• 1,1'-Bi-2-naphthol
• Terbinafine Hydrochloride
• 2-Naphthol
• CHLOROPHOSPHONAZO III
• 1-Naphthol
• PHENOLDISULFONIC ACID
• 4-Amino-5-methoxy-2-methylbenzensulfonic acid
• 6,6'-Oxybis-
• Acid Green 1
• Sodium 2,3-dihydroxynaphthalene-6-sulfonate
• Ponceau S
• Acid Red 73
• Acid Red 27
• ACID RED 26
• 1-NITROSO-2-NAPHTHOL-3,6-DISULFONIC ACID DISODIUM SALT