4,5-Dihydro-5-oxo-4-[(3-phosphonophenyl)azo]-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylic acid

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