disodium 5-[[4'-[[2,4-dihydroxy-3-[(4-sulphonatophenyl)azo]phenyl]azo][1,1'-biphenyl]-4-yl]azo]salicylate

Preparation

4-(4-Aminophenyl)benzenamine double nitriding, 4-Aminobenzenesulfonic acid?coupled with first, then and Resorcinol coupling, 2-Aminobenzenesulfonic acid diazo, and formation of accidentally coupled nitrogen compounds.

Properties and Applications

brown. Soluble in water for yellow brown, slightly soluble in soluble fiber element, insoluble in other organic solvents. The strong sulfuric acid to red light purple, yellow light brown after diluted precipitation. The dye solution to join strong hydrochloric acid have yellow brown precipitation; Add thick, hydrogen oxidation solution for orange to red.