Nitriles in heterocyclic synthesis. Part II: Synthesis and application of pyrano[3,2-h]quinoline sulphonamide derivatives

5-Sulphonamido-8-quinolinol reacts with cinnamonitrile derivatives in the presence of a basic catalyst to give pyrano[3,2-h]quinoline sulphonamide derivatives (8a-d-13a-d). The reaction of 8b, 9b with some reagents such as acetic anhydride, acetic anhydride/pyridine mixture, formamide and formic acid/formamide mixture gave the fused heterotetracyclic systems pyrimido-[4′, 5′: 6, 5]pyrano[3, 2-h] quinoline sulphonamide derivatives. The structures of all newly synthesized compounds were confirmed by elemental analyses and spectral data. These compounds showed antimicrobial activity against some selected bacteria in vitro.