8-[[3,3'-dimethyl-4'-[[4-[[(p-tolyl)sulphonyl]oxy]phenyl]azo][1,1'-biphenyl]-4-yl]azo]-7-hydroxynaphthalene-1,3-disulphonic acid

8-[[3,3'-Dimethyl-4'-[[4-[[(4-methylphenyl)sulfonyl]oxy]phenyl]azo][1,1'-biphenyl]-4-yl]azo]-7-hydroxy-1,3-naphthalenedisulfonic acid