Preparation
2,4-Diaminobenzenesulfonic acid diazo, and 3-(3-Methyl-5-oxo-2H-pyrazol-1(5H)-yl)naphthalene-1,5-disulfonic acid?coupling, and 2,4,6-Trichloro-1,3,5-triazine condensation, the product with a again between, 2-(3-Aminophenylsulfonyl)ethyl hydrogen sulfate condensation.