Metal- and solvent-free synthesis of N-sulfonylformamidines

A solvent-free green synthesis of N-sulfonylformamidines is reported viathe direct condensation of N,N-dimethylformamide dimethyl acetal (DMF-DMA) and sulfonamide derivatives at room temperature. The described method avoids the use of metal catalysts as well as hazardous solvents, which are not permitted for pharmaceutical manufacture, for the reactions or isolation of products. Hence, the current work presents a fast and efficient alternative to earlier reported methods. The mild nature of the procedure is demonstrated by varied functional group tolerance.