1-(4-Amino-2-sulfophenyl)-4,5-dihydro-5-oxo-4-[(2-sulfophenyl)azo]-1H-pyrazole-3-carboxylic acid

1-(4-amino-2-sulphophenyl)-4,5-dihydro-5-oxo-4-[(2-sulphophenyl)azo]-1H-pyrazole-3-carboxylic acid