Efficient N-acylation of sulfonamides using cesium salt of Wells–Dawson heteropolyacid as catalyst: Synthesis of new N-acyl sulfonamides and cyclic imides

N-acylation of substituted sulfonamides with different anhydrides in the presence of Cesium salt of Wells–Dawson heteropolyacid (Cs₅HP₂W₁₈O₆₂) as an efficient and reusable catalyst was investigated for the first time.

 Cs₅HP₂W₁₈O₆₂ was used with a catalytic amount in water as a green solvent. At room temperature, a series of N-acylsulfonamides were synthesized, while under refluxing conditions, new cyclic imides containing sulfonyl group were obtained. Atom-economy, high yields, easy work-up, as well as simple catalyst recovery and reusability are the key features of this procedure.