4-[3-[3-Carboxy-5-hydroxy-1-[2,5-di(potassiosulfo)phenyl]-1H-pyrazol-4-yl]-2-propen-1-ylidene]-5-oxo-1-[2,5-di(potassiosulfo)phenyl]-2-pyrazoline-3-carboxylic acid

4-[3-[3-Carboxy-1-(2,5-dipotassiosulfophenyl)-5-hydroxy-1H-pyrazol-4-yl]-2-propenylidene]-1-(2,5-dipotassiosulfophenyl)-4,5-dihydro-5-oxo-1H-pyrazole-3-carboxylic acid