12237-57-9 16013-44-8 2-Naphthalenecarboxylic acid, 4-((5-chloro-4-methyl-2-sulfophenyl)azo)-3-hydroxy- 4-((5-Chloro-4-methyl-2-sulphophenyl)azo)-3-hydroxy-2-naphthoic acid EINECS 240-150-6