Synthesis of 2,4-dichlorophenyl methanesulfonate labeled with 14C and 35S

Radioactive 2,4-dichlorophenyl methanesulfonate labeled with ¹⁴C and ³⁵S has been synthesized because it was needed to facilitate the study of the metabolic fate of this interesting nematicide. It was prepared from the reaction between methanesulfonyl chloride and 2,4-dichlorophenol in the presence of a base. Three hundred milligrams of each ¹⁴C- and ³⁵S-2,4-dichlorophenyl methanesulfonate was obtained in a yield of 87% based on ¹⁴C-2,4-dichlorophenol or ³⁵S-methanesulfonyl chloride, respectively. The specific activity was 3.8 mCi/mmol for the compound labeled with ³⁵S and 2.5 mCi/mmol for the ¹⁴C material. Both tracers assayed over 99% after purification.