1-AMINO-2-NAPHTHALENESULFONIC ACID Chemical Properties

Density 

1.3588 (rough estimate)

refractive index 

1.6500 (estimate)

pka

pK1: 1.71 (25°C)

Water Solubility 

4.1g/L(20 ºC)

EPA Substance Registry System

2-Naphthalenesulfonic acid, 1-amino- (81-06-1)

1-AMINO-2-NAPHTHALENESULFONIC ACID Usage And Synthesis

Chemical Properties

1-Aminonaphthalene-2-sulfonic acid [81- 06-1]. ortho-naphthionic acid, C10H9NO3S, Mr 223.24, mp 262 – 265℃ (decomp.), is sparingly soluble in cold water but dissolves in hot water to give a 3 % solution. The sodium salt is more readily soluble in water (1.7 % at 20℃ and 10 % at 100℃). The calcium salt is similarly soluble, but the barium salt is almost insoluble.

Production Methods

1-Naphthylamine can be sulfonated by heating with sulfuric acid at 180 – 185℃, but the transient intermediate naphthalene-1-sulfamic acid is best prepared from 1-aminonaphthalene-4-sulfonic acid (naphthionic acid). When sodium naphthionate is heated in a solvent such as o-dichlorobenzene or xylene at 225℃, thermal rearrangement occurs to give the 1,2-isomer in high yield.

1-AMINO-2-NAPHTHALENESULFONIC ACID(81-06-1)Related Product Information

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