The Metabolism of 4′-Chloro-4-biphenylol in the Rat

4′-Chloro-4-biphenylol, the major metabolite of 4-chlorobiphenyl in the rat, was given intraperitoneally to rats, and the urine and feces were examined for possible metabolic degradation products. The structure of the major urinary metabolite was elucidated by mass and nuclear magnetic resonance spectroscopy and shown to be 4′-chloro-3,4-biphenyldiol. Two chloromethoxybiphenylols (M+ 234) were also identified in the urine extracts but they could not be separated by chromatographic procedures. Demethylation of the mixture gave 4′-chloro-3,4-biphenyldiol as the sole product, thus indicating that the two components of the mixture were 4′-chloro-3-methoxy-4-biphenylol and 4′-chloro-4-methoxy-3-biphenylol. A fourth urinary metabolite was identified as 4′-chloro-4-methoxy-3,5-biphenyldiol. No 4′-chloro-4-biphenylol metabolites were isolated in the fecal extracts, and mass spectrometric analysis of the crude urine and feces extracts did not reveal any chlorine-containing degradation products that could be derived by oxidative fission of the biphenyl nucleus.