4-Hydroxy-6-[[3-[(2-hydroxy-3-nitro-5-sodiosulfophenyl)azo]-2,4-dihydroxyphenyl]azo]-3-[(4-nitrophenyl)azo]naphthalene-2-sulfonic acid sodium salt

Preparation

6-Amino-4-hydroxynaphthalene-2-sulfonic acid? diazo, Coupled with resorcinol, 4-Nitrobenzenamine diazo, and the generation of single accidentally coupled nitrogen compounds, and then and diazo 3-Amino-4-hydroxy-5-nitrobenzenesulfonic acid coupling.

Properties and Applications

dark red light brown. Soluble in water for orange brown. The strong sulfuric acid for wine, dilute after brown precipitation. In water solution to join strong hydrochloric acid for orange brown; With rare sodium hydroxide solution for blue-ray red.