1-Aminonaphthalene-6-sulfonic acid Property

Melting point:

>300°C

Density 

1.3588 (rough estimate)

vapor pressure 

0Pa at 25℃

refractive index 

1.6500 (estimate)

storage temp. 

Refrigerator

solubility 

soluble100mg/mL, clear, brown (1N NH4OH)

form 

Solid

pka

pK1: 3.80 (25°C)

color 

Purple

Water Solubility 

1g/L(16 ºC)

Merck 

14,2350

BRN 

1819887

Dissociation constant

0 at 39℃

CAS DataBase Reference

119-79-9(CAS DataBase Reference)

NIST Chemistry Reference

1-Naphthylamine-6-sulfonic acid(119-79-9)

EPA Substance Registry System

2-Naphthalenesulfonic acid, 5-amino- (119-79-9)

Safety

Risk Statements 

36/37/38

Safety Statements 

26-36/37/39-24/25

RIDADR 

1759

WGK Germany 

1

RTECS 

QK1285000

TSCA 

Yes

HazardClass 

8

PackingGroup 

III

HS Code 

29309090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

Precautionary statements

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

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

1-Aminonaphthalene-6-sulfonic acid Chemical Properties,Usage,Production

Chemical Properties

Purple Solid. 1-Aminonaphthalene-6-sulfonic acid [119- 79-9]. (5-aminonaphthalene-2-sulfonic acid), 1,6-Cleve’s acid, C10H9NO3S, Mr 223.24, crystallizes from boiling water as plates of the dihydrate. Its sodium, potassium, and calcium salts are all readily soluble in water, but the barium salt is only sparingly soluble. Sulfonation with 10 % oleum yields 1-aminonaphthalene-4,6-disulfonic acid. Caustic fusion gives 5- amino-2-hydroxynaphthalene, and Bucherertype hydrolysis gives 1-hydroxynaphthalene-6- sulfonic acid.

Uses

Fluorescent reagent.

Uses

Intermediate of dyestuff

Uses

5-Amino-2-naphthalenesulfonic acid (1,6-Cleve′s acid) was used in the synthesis of nitrate reductase and detection of nitrate reduction by anaerobic bacteria.

Definition

ChEBI: 5-aminonaphthalene-2-sulfonic acid is an aminonaphthalenesulfonic acid.

Production Methods

Sulfonation of 1-naphthylamine with concentrated sulfuric acid at 130℃ gives mainly 1-aminonaphthalene-6-sulfonic acid. However, the latter is always made, together with the 1,7-isomer, by nitration of naphthalene-2-sulfonic acid to give the mixed 5- and 8- nitronaphthalene-2-sulfonic acids follwed by reduction to ‘‘mixed Cleve’s acids.’’ A b-sulfonation mass is diluted with sulfuric acid, then 67.5 % nitric acid is added slowly at 34℃. After being quenched and neutralized with calcium carbonate, the filtered liquor is reduced by boiling with iron powder, slight acidity being maintained with sulfuric acid. After basification with magnesia the iron residues are filtered off and the filtrate is evaporated until the magnesium salt of the product crystallizes on cooling. Filtration followed by washing with magnesium sulfate gives a 34 % yield of the magnesium salt of 1,6-Cleve’s acid. Purification by dissolution in hot water, acidification, and filtration of the free acid while hot reduce the yield to 25 % based on naphthalene.

General Description

The crystal structure of 5-amino-2-naphthalenesulfonic acid (1,6-Cleve′s acid) depicted the presence of a sulfonate-aminium group zwitterion.