4-[[4-[[(3,6-Dichloropyridazin-4-yl)carbonyl]amino]-2-sulfophenyl]azo]-4,5-dihydro-5-oxo-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylic acid

4-[[4-[[(3,6-dichloropyridazin-4-yl)carbonyl]amino]-2-sulphophenyl]azo]-4,5-dihydro-5-oxo-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid