3442-21-5 Benzoic acid, 5-((4-((7-amino-1-hydroxy-3-sulfo-2-naphthalenyl)azo)-1-naphthalenyl)azo)-2-hydroxy-, disodium salt Benzoic acid, 5-((4-((7-amino-1-hydroxy-3-sulfo-2-napthalenyl)azo)-1-naphthalen- yl)azo)-2-hydroxy-, disodium salt CI 27720 Direct black 51 Disodium 5-((4-((7-amino-1-hydroxy-3-sulphonato-2-naphthyl)azo)-1-naphthyl)azo)salicylate EINECS 222-351-0 Saturn black B