Synonyms: disodium 3,3’-[(2,2’-dimethyl[1,1’-biphenyl]-4,4’-diyl)bis[azo(4,5-dihydro-3-methyl-5-oxo-1H-pyrazole-4,1-diyl)]]bis[4-chlorobenzenesulphonate];Benzenesulfonic acid, 3,3’-[(2,2’-dimethyl[1,1’- biphenyl]-4,4’-diyl)bis[azo(4,5-dihydro-3-methyl -5-oxo-1H-pyrazole-4,1-diyl)]]bis[4-chloro-, disodium salt