4,4'-Dichlorobiphenyl in rabbits gave three major urinary metabolites: 4,4'-dichlorobiphenyl-3-ol, 3,4'-dichlorobiphenyl-4-ol, and 4'-chlorobiphenyl-4-ol. 4,4'-Dibromobiphenyl gave the bromo analogues of the three 4,4'-dichlorobiphenyl metabolites. These results are consistent with 3,4-epoxidation of the biphenyl nucleus followed by epoxide ring opening accompanied by a 1,2-halogen shift (NIH shift). 4,4'-Di-iodobiphenyl gave only a single metabolite, 4,4'-di-iodobiphenyl-3-ol, and rearrangement products were not observed. Royal Society of Chemistry.
