An environmentally benign approach for the synthesis of bifunctional sulfonamide-amide compounds via isocyanide-based multicomponent reactions

Three-component reaction of the zwitterion generated from dialkyl acetylenedicarboxylate and an alkyl or aryl isocyanide with an alkyl or aryl sulfonamide is described. The reaction afforded the corresponding special type of ketenimine sulfonamide derivatives in water without using any activation and modification. The products could be easily hydrolyzed to the corresponding sulfonamide-butanamide derivatives at 80 degrees C in good yields without using a catalyst.