2-((4,5-Dihydro-3-methyl-1-(2-methyl-4-sulfophenyl)-5-oxo-1H-pyrazol-4-yl)azo)-4-sulfobenzoic acid 68400-28-2 68957-71-1 Benzoic acid, 2-((4,5-dihydro-3-methyl-1-(2-methyl-4-sulfophenyl)-5-oxo-1H-pyrazol-4-yl)azo)-4-sulfo-