Solvent-Free Synthesis and Antibacterial Evaluation of Novel Coumarin Sulfonamides

A series of new coumarin-6-sulfonamides have been synthesized as potential antibacterial agents. The reaction of coumarin with chlorosulfonic acid was found to yield the corresponding coumarin sulfonyl chloride (1). In the next step, coumarin sulfonyl chloride, was reacted with various amines in the presence of K2CO3 under solvent-free conditions to produce coumarine sulfonamides (2a - 2s) in good to excellent yields. The chemical structures of the products were elucidated by IR, H-1 NMR, and C-13 NMR spectroscopy and elemental analysis. All the synthesized compounds have been screened for their in vitro anti-bacterial activities against Escherichia coli and Staphylococcus aureus bacteria.