Synonyms: Benzenesulfonic acid, 4-(2-(2,4-dihydroxy-3-(2-(4-methylphenyl)diazenyl)phenyl)diazenyl)-, sodium salt (1:1);Benzenesulfonic acid, 4-((3-((4-methylphenyl)azo)-2,4-dihydroxyphenyl)azo)-, monosodium salt;Benzenesulfonic acid, 4-((2,4-dihydroxy-3-((4-methylphenyl)azo)phenyl)azo)-, monosodium salt;Sodium 4-((2,4-dihydroxy-3-((4-m-tolyl)azo)phenyl)azo)benzenesulphonate;sodium 4-[(2E)-2-{(5Z)-5-[2-(4-methylphenyl)hydrazinylidene]-4,6-dioxocyclohex-2-en-1-ylidene}hydrazinyl]benzenesulfonate