Acid Yellow 158:1

synthetische2,5-Diaminobenzenesulfonic acid first and 2,4,6-Trichloro-1,3,5-triazine condensation, and again 3-Aminobenzenesulfonic acidcondensation, and then diazo, and 2,5-Bichloro-4-(3-methyl-5-oxo-4,5-dihydropyrazol-1-yl)benzenesulfonic acidcoupling, and finally hydrolysis.