Synonyms: Benzoic acid, 4,4'-(carbonylbis(imino(1-hydroxy-3-sulfo-6,2-naphthalenediyl)-2,1-diazenediyl))bis-, compd. with 2,2'-iminobis(ethanol) (1:4);4,4'-Ureylenebis((1-hydroxy-3-sulfo-6,2-naphthalenediyl)-2-azo)dibenzoic acid, diethanolamine salt (1:4);4,4'-(Carbonylbis(imino(1-hydroxynaphthalene-6,2-diyl-3-sulpho)azo))bisbenzoic acid, compound with 2,2'-iminobis(ethanol) (1:4);Benzoic acid, 4,4'-(carbonylbis(imino(1-hydroxy-3-sulfo-6,2-naphthalenediyl)azo))bis-, compd. with 2,2'-iminobis(ethanol) (1:4);4-[(2E)-2-{6-[({(6Z)-6-[(4-carboxyphenyl)hydrazono]-5-oxo-7-sulfo-5,6-dihydronaphthalen-2-yl}carbamoyl)amino]-1-oxo-3-sulfonaphthalen-2(1H)-ylidene}hydrazino]benzoic acid - 2,2'-iminodiethanol (1:4)