Reaction of N-sulfinyltrifluoromethanesulfonamide with carbodiimides: Formation of N-trifluoromethanesulfonyl-2,4-dialkyl-1,2,4-thiadiazetidin-3-imine 1-oxides

N-sulfinyltrifluoromethanesulfonamide was found to react with diisopropyl- and dicyclohexylcarbodiimides with the formation of N-trifluoromethanesulfonyl-2,4-dialkyl-1,2,4-thiadiazetidin-3-imine 1-oxides. The mechanism includes the [2π + 2π] cycloaddition resulting in 2-trifluoromethanesulfonyl-3-alkylimino-4-alkyl-1,2,4-thiadiazetidine 1-oxides, the ring opening of the latter, rotation about the CN bond and the ring closure to the final products.