The reaction of dimethyl sulfoxide–trifluoroacetic anhydride complex with anilines, phenols, and thiophenols was studied, and the following results were obtained.(1) The yields of a methylthiomethylated product were improved with anilines. The reaction proceeded without significant amount of tar, the unreacted anilines being easily recovered.(2) Selective ortho- methylthiomethylation took place with phenols in good yields at lower temperature, para- ...