33DICHLORO55BENZIDINEDISULPHONICACID

3,3'-Dichloro-5,5'-benzidine_disulfonic_acid

4,4'-Diamino-3,3'-dichlorobiphenyl-5,5'-disulfonic acid

4,4'-Diamino-5,5'-dichloro-[1,1'-biphenyl]-3,3'-disulfonic acid