1-Phenol-2-sulfonic acid, 4-amino- 2835-04-3 4-Hydroxy-3-sulfoaniline 5-Amino-2-hydroxybenzenesulfonic acid 5-Amino-2-hydroxyphenylsulfonic acid 5-Amino-o-phenolsulfonic acid Benzenesulfonic acid, 5-amino-2-hydroxy- Metanilic acid, 6-hydroxy- NSC81214