4,4'-Bis(pyrocatecholylazo)-3,3'-dimethylbiphenyl

4,4'-[(3,3'-Dimethyl[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bispyrocatechol

4,4'-[(3,3'-Dimethyl[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis-1,2-benzenediol