2-Naphthylamine-5,7-disulfonic acid

Chemical properties

White glossy long prismatic needle-like crystals, the crystals precipitated from water contain 5 molecules of crystal water. The solubility in water at 20°C is 23%. Its monosodium salt and monopotassium salt are commonly used in industry, both of which are soluble in water, and the salt solution has green fluorescence.

The Uses of 2-Naphthylamine-5,7-disulfonic acid

2-Naphthylamine-5,7-disulfonic acid is an intermediate for the preparation of J acid, bis-J acid, phenyl J acid and scarlet acid.

Hazard

Skin - Rabbit 2 mg/24h severe; Eye - Rabbit 0.75 mg/24h severe

Flammability and Explosibility

Not classified

Synthesis

2-Naphthylamine-5,7-disulfonic acid can be obtained by hydrolysis of 2-naphthylamine-1,5,7-trisulfonic acid. Add sulfuric acid, sodium sulfate and 2-naphthylamine-1,5,7-trisulfonic acid into water, keep warm at 110-120°C for 4 hours, cool and filter, and wash in sodium sulfate solution to obtain the product.