2,7-Naphthalenedisulfonic acid, 4-amino-3-((4-((2,4-diaminophenyl)azo)phenyl)azo)-5-hydroxy-6-(phenylazo)-, disodium salt 68877-33-8 Disodium 4-amino-3-((4-((2,4-diaminophenyl)azo)phenyl)azo)-5-hydroxy-6-(phenylazo)naphthalene-2,7-disulphonate EINECS 272-559-0