Improved synthesis of <i>N</i>-sulfonylformamidine derivatives promoted by thionyl chloride

<p></p> <p>An improved synthesis of <i>N</i>-sulfonylformamidine derivatives has been developed involving direct condensation of various sulfonamides and formamides in the presence of thionyl chloride using chloroform as solvent. Detailed synthetic studies indicate that this procedure gives the desired products in high yields under mild conditions.</p>