Preparation
the 2-Aminobenzenesulfonic acid diazo, in alkaline conditions and 4-Amino-5-hydroxynaphthalene-2,7-disulfonic acidcoupling, and 2,4,6-Trichloro-1,3,5-triazine condensation, condensation products again with registration, 2-(3-Aminophenylsulfonyl)ethyl hydrogen sulfate condensation.