3-[[2,2'-dimethyl-4'-[[4-[[(p-tolyl)sulphonyl]oxy]phenyl]azo][1,1'-biphenyl]-4-yl]azo]-4-hydroxynaphthalene-2,7-disulphonic acid

3-[[2,2'-Dimethyl-4'-[[4-[[(4-methylphenyl)sulfonyl]oxy]phenyl]azo]-1,1'-biphenyl-4-yl]azo]-4-hydroxy-2,7-naphthalenedisulfonic acid