O- and S-methylated bromothiocatechols.

Bromobenzene is metabolized by the Hartley guinea pig to two different bromothiocatechols, 4-bromo-2-hydroxythiophenol and 5-bromo-2-hydroxythiophenol. Both the thiol and phenol functional groups of thiocatechol undergo biological methylation. Methylation at the thiol group leads to the formation of (methylthio)bromophenol (S-methylated bromothiocatechol), while methylation of the phenol group leads to methoxybromothiophenol (O-methylated bromothiocatechol). This resulted in the urinary excretion of four O- and S-methylated bromothiocatechols. Bromothiocatechols could be formed by dehydrogenation of their corresponding bromodihydrobenzene thiolols. Both the 3-S- and 4-S-bromodihydrobenzene thiolols, as S-methylated products, were found as urinary metabolites of bromobenzene in the Hartley guinea pig. All four O- and S-methylated bromothiocatechols and two S-methylated bromodihydrobenzene thiolols were also found as urinary metabolites of bromobenzene in the golden Syrian hamster.