sodium 4-[4-[(2,5-dimethylphenyl)azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulphonate

4-[[4-[(2,5-Dimethylphenyl)azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol]-1-yl]benzenesulfonic acid sodium salt