4,4'-diaminobenzanilide 3,4'-Diaminobenzanilide naphthoquinophthalone 3-Carbamoyl-4-methyl-6-hydroxy-N-ethyl pyridone 3-Sulfomethyl-4-methyl-5-carbamoyl-6-hydroxy-N-ethyl pyridone 4,4’-Diamino-2-methylazobenzene Phenyl, 2-aminobenzenesulfonate 2-Chlorophenyl-2-aminobenzenesulfonate p-Aminoazobenzene sulfonic acid