Synonyms: Cuprate(1-),[3-[[[(3-amino-4-nitrophenyl)azo]-2,4-dihydroxyphenyl]azo]-4-hydroxybenzenesulfonato(3-)]-,sodium; Cuprate(1-), [3-[[[(3-amino-4-nitrophenyl)azo]-2-(hydroxy-kO)-4-hydroxyphenyl]azo-kN1]-4-(hydroxy-kO)benzenesulfonato(3-)]-, sodium(9CI); Benzenesulfonic acid,3-[[[(3-amino-4-nitrophenyl)azo]-2,4-dihydroxyphenyl]azo]-4-hydroxy-, coppercomplex