Synonyms: 6359-74-6;EINECS 228-805-4;Sodium p-((4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo)benzenesulphonate;Benzenesulfonic acid, 4-((4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo)-, sodium salt;Benzenesulfonic acid, 4-(2-(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)diazenyl)-, sodium salt (1:1);Benzenesulfonic acid, 4-[(4,5-dihydro-3-methyl- 5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-, sodium salt