4-[(2,5-Dichlorophenyl)azo]-1-(2-chloro-5-sodiosulfophenyl)-3-methyl-5(4H)-pyrazolone

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