Metabolism of 4,4′-dihalogenobiphenyls

Abstract

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.