2-amino -1-naphthalenesulfonic acid

2-amino -1-naphthalenesulfonic acid (CAS number: 81-16-3), alias totic acid, Tobias acid, is an important organic chemical raw materials, mainly used as azo dyes and azo pigments intermediates.

Physical and Chemical Properties of 1.

Molecular formula: C≡No_H≡NO_3 S

Molecular weight: 223.25g/mol

Appearance: white to pink needle-like crystals, exposed to the air easily become pink to dark red.

Solubility: slightly soluble in cold water and ethanol, ether, soluble in hot water, soluble in liquid alkali.

Melting point: about 220°C (rough estimate).

1.502g/cm³ 。

Refractive index: 1.5250 (estimated value).

2. Main Uses

1. Dye intermediates:

Used in the manufacture of J acid, gamma acid, phenol AS-SW, reactive red K-1613 and other dyes.

Used in the synthesis of organic purple, Lisol purple, Lisol red R and other pigments.

2. Other applications:

Used as mothproofing agent (historical use, less common now)