Benzoic acid, 5-[[4-[[7-[(2,4-diaminophenyl)azo]-1-hydroxy-3-sulfo-2-naphthalenyl]azo]-1-naphthalenyl]azo]-2-hydroxy-, disodium salt

5-Amino-2-hydroxybenzoic acid diazo, and Naphthalen-1-amine coupling, again diazo, in alkaline conditions and 6-Amino-4-hydroxynaphthalene-2-sulfonic acid? coupling, product to diazo, and Benzene-1,3-diamine coupling.

green light grey. Soluble in water for green light black. The strong sulfuric acid for blue-ray green, red after dilute black precipitation. The dye solution to join strong hydrochloric acid have green light black precipitation; Add thick sodium hydroxide solution have blue-ray black precipitation.