Ionic liquid-supported synthesis of sulfonamides and carboxamides.

An ionic liquid-supported aldehyde was designed and converted to ionic liquid-supported secondary aryl amines through reductive amination. The reaction of ionic liquid-supported aryl amines with sulfonyl chlorides and acid chlorides, respectively, followed by cleavage using trifluoroacetic acid (TFA) afforded sulfonamides and caboxamides. To introduce additional diversity in the synthesis of sulfonamides and caboxamides, ionic liquid-supported iodosubstituted aryl amine was synthesized using the same strategy, and underwent Suzuki coupling reaction, followed by reaction with a methanesulfonyl chloride to generate the corresponding biaryl sulfonamide. The advantages of the protocol over solid-phase synthesis are homogeneous reaction medium, high loading, easy separation of products, and characterization of intermediates.