1,2,4-acid

Name:
1,2,4-acid
Detailed information:

Chemistry name:	1-amino-2-naphthol-4-sulfonic acid
M Formula:	C10H5NH2OHSO3H
Properties:
Pinkish-white to gray needles. Soluble in hot water; but almost insoluble in cold water.
Derivation:
β-naphthol is nitrated to nitroso-β-naphthol by reaction with nitrous acid and the product treated with sodium bisulfite. Upon acidification the free sulfurous acid effects simultaneous reduction and sulfonation.
Use:
Aniline dye intermediate.