trisodium 2,4-bis[[2,4-diamino-5-[(3-sulphonatophenyl)azo]phenyl]azo]benzenesulphonate

3-Aminobenzenesulfonic acid diazo, and the coupling Benzene-1,3-diamine, its product (2 Moore) and double the nitride 2,4-Diaminobenzenesulfonic acid (1 Moore) coupled.

red light brown. Soluble in water for yellow light brown. For the strong sulfuric acid in dark brown, diluted into a tan. In water solution to join strong hydrochloric acid with brown precipitation; Add thick sodium hydroxide solution for orange brown.