Replacement of a chlorine with a methylsulfonyl group in the metabolism of propachlor (2-chloro-N-isopropylacetanilide).

Urine from rats and sheep given single doses of [14C]propachlor contained 14C metabolites in which the chlorine of propachlor was replaced by a methylsulfonyl group. Methylsulfonyl-containing metabolites were also isolated from the urine of rats given an intraperitoneal dose of the cysteine conjugate of [14C]propachlor; this indicated that the methylsulfonyl-containing metabolites resulted from metabolic reactions subsequent to the mercapturic acid pathway.