Reaction of sulfonamides with carboxylic acid anhydrides and chlorides in the presence of silica phosphoric acid provided N-acyl sulfonamides in good to high yields. All reactions were performed under mild conditions in solvent-free and heterogeneous systems and the products were obtained in high purity after a simple work-up. Silica phosphoric acid could be reused for 3 times without visible loss of activity.
MASSAH, AHMAD REZA; DABAGH, MINA; AFSHAR, MARYAM; MOMENI, AHMAD REZA; ALIYAN, HAMID; and NAGHASH, HAMID JAVAHERIAN (2007) "A Convenient and Efficient Synthesis of N-Acylsulfonamides in the Presence of Silica Phosphoric Acid under Heterogeneous and Solvent-Free Conditions," Turkish Journal of Chemistry: Vol. 31: No. 6, Article 6. Available at: https://journals.tubitak.gov.tr/chem/vol31/iss6/6