Synonyms: 2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-3-(2-(4-(2-(4-sulfophenyl)diazenyl)phenyl)diazenyl)-, compd. with 2,2'-iminobis(ethanol) (1:2);7-Amino-4-hydroxy-3-(4-(4-(sulfophenyl)azo)phenylazo)-2-naphthalenesulfonic acid, di(bis(2-hydroxyethyl)ammonium)salt;2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-3-((4-((4-sulfophenyl)azo)phenyl)azo)-, compd. with 2,2'-iminobis(ethanol) (1:2);7-Amino-4-hydroxy-3-((4-((4-sulphophenyl)azo)phenyl)azo)naphthalene-2-sulphonic acid, compound with 2,2'-iminodiethanol (1:2);(3E)-7-amino-4-oxo-3-(2-{4-[(E)-(4-sulfophenyl)diazenyl]phenyl}hydrazinylidene)-3,4-dihydronaphthalene-2-sulfonic acid - 2,2'-iminodiethanol (1:2)