sodium 4-chloro-3-[4-[[3-[[(2-ethylphenyl)amino]sulphonyl]-p-tolyl]azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulphonate

4-Chloro-3-[[4-[[3-[[(2-ethylphenyl)amino]sulfonyl]-4-methylphenyl]azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol]-1-yl]benzenesulfonic acid sodium salt