10132-99-7 4-(4-((3-Chloro-2-hydroxy-5-nitrophenyl)azo)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl)benzenesulfonic acid, sodium salt Benzenesulfonic acid, 4-(4-((3-chloro-2-hydroxy-5-nitrophenyl)azo)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl)-, monosodium salt EINECS 233-373-5 Sodium 4-(4-((3-chloro-2-hydroxy-5-nitrophenyl)azo)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl)benzenesulphonate