Selective reaction of sulfanilamide with acetic anhydride catalyzed by stannous oxide nanoparticles

Sulfonamide compounds with functional group -SO2NH- show a wide range of biological activities and medicinal properties. The synthesis of sulfonamides has been of interest to medicinal chemists for a long time. In this article, the selective acylation of sulfanilamide with acetic anhydride was carried out using some catalysts with Lewis acid properties. In this research, the one-pot selective method of N-acylation of -SO2NH2 group in sulfanilamide molecule using stannous oxide nanoparticles as an efficient recyclable catalyst has been used. In this method, THF was replaced with expensive toxic amine solvents. The acylated product was identified by FTIR, 1HNMR, 13CNMR and MASS spectra. The best results with 85% efficiency, 95% selectivity were obtained using stannous oxide nanoparticles as catalyst (0.5 g) in tetrahydrofuran as solvent, at 60°C in 60 minutes. The catalyst was recycled three times and maintained its efficiency. Using this method is completely green and has economic and environmental benefits.