3-((4,5-Dihydro-5-oxo-1,3-diphenyl-1H-pyrazol-4-yl)azo)-2-hydroxy-5-nitrobenzenesulphonic acid 64743-14-2 Benzenesulfonic acid, 3-((4,5-dihydro-5-oxo-1,3-diphenyl-1H-pyrazol-4-yl)azo)-2-hydroxy-5-nitro- EINECS 265-214-0