2-Naphthalenesulfonic acid, 7-[(4-aminobenzoyl)amino]-4-hydroxy-3-[[2-methyl-4-[(2-methyl-4-sulfophenyl)azo]phenyl]azo]-, disodium salt

Preparation

2′,3-Dimethyl-4-amino-4′-sulfoazobenzene diazo, and 7-(4-Aminobenzamido)-4-hydroxynaphthalene-2-sulfonic acid coupling.

Properties and Applications

blue-ray red. Soluble in water for blue-ray red, and adequate soluble in alcohol for product red. The strong sulfuric acid in blue, diluted red for brown. The dye solution with strong hydrochloric acid have red orange brown precipitation; Add thick sodium hydroxide solution is Claret precipitation. And C.I. Direct Red 127 similar.