[(4-amino-2-sulphophenyl)amino]oxoacetic acid 3-(4-amino-2-sulfophenylamino)-2,3-dioxo propanoic acid 4'-Amino-2'-sulfooxanilic acid N-(4-Amino-2-sulfophenyl)oxamidic acid Einecs 228-851-5 2-(4-amino-2-sulfoanilino)-2-oxoacetic acid Acetic acid, 2-[(4-amino-2-sulfophenyl)amino]-2-oxo-