Cycloaddition in Synthesis of Sulfonamide Derivatives.II. : Synthesis of N-Arylsulfonylethoxalamides by Cycloaddition of Arylsulfonyl Isocyanates to Ethyl Oxamates
A new class of sulfonamides, N2-arylsulfonyl-N1, N1-disubstituted ethoxalamidines, was synthesized by reaction of arylsulfonyl isocyanates with N, N-disubstituted ethyl oxamates. It was suggested that the reacion might proceed through [2+2] cycloaddition of the isocyanates to an amide carbonyl moiety with high selectivity.
