2-(4-((p-Hydroxyphenyl)azo)phenylamino)-5-nitrobenzenesulfonic acid, sodium salt 67674-21-9 Benzenesulfonic acid, 2-((4-((4-hydroxyphenyl)azo)phenyl)amino)-5-nitro-, monosodium salt Benzenesulfonic acid, 2-((4-((p-hydroxyphenyl)azo)phenyl)amino)-5-nitro-, sodium salt EINECS 266-860-6 Sodium 2-((4-((4-hydroxyphenyl)azo)phenyl)amino)-5-nitrobenzenesulphonate