In this study, an efficient one-pot reaction is reported for the synthesis of a new class of pseudopeptide connected to sulfonamide via a tandem N-sulfonylation/Ugi four-component reaction (Ugi-4CR) strategy under mild conditions in high yields. This five-component reaction strategy is carried out by readily available starting materials, sulfonyl chlorides, glycines, benzylamines, benzaldehydes, and isocyanides, in ethanol/water at room temperature. The generation of carboxylic acid that is a key component in Ugi-4CR could be accomplished by performing the N-sulfonylation reaction, and it could be used in the next step without further purification. The as-synthesized compounds that are constructed from pseudopeptide connected to a sulfonamide scaffold have the potential to be used in designing modern drugs with the highly desirable feature. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.