Synonyms: Cuprate(4-),[m-[[2,2'-[1,2-ethenediylbis[(3-sulfo-4,1-phenylene)-ONN-azoxy(1-hydroxy-3-sulfo-7,2-naphthalenediyl)azo]]bis[benzoato]](8-)]]di-,tetrasodium; Cuprate(4-), [m-[[2,2'-[1,2-ethenediylbis[(3-sulfo-4,1-phenylene)-ONN-azoxy[1-(hydroxy-kO)-3-sulfo-7,2-naphthalenediyl]azo-kN1]]bis[benzoato-kO]](8-)]]di-, tetrasodium (9CI);Benzoic acid,2,2'-[1,2-ethenediylbis[(3-sulfo-4,1-phenylene)-ONN-azoxy(1-hydroxy-3-sulfo-7,2-naphthalenediyl)azo]]bis-,copper complex