Metabolism of crufomate [(4-tert-butyl-2-chlorophenyl methyl methylphosphormidate)] by the rat.

Fifteen metabolites of crufomate (4-tert-butyl-2-chlorophenyl methyl methylphosphoramidate, I) were identified in the excreta from rats given single oral doses of I. Compound I was not detected in either the urine or the feces. The metabolic reactions observed were N-and O-demethylation, oxidations of the t-butyl moiety, replacement of the H-N-CH3 with an OH moiety, hydrolysis of the phosphoramidate moiety to yield the phenol, conjugation with glucuronic acid, and combinations of these reactions. No ring dehalogenation or ring substitution was observed.