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 ( 8 a‐d ‐13 a‐d ). The reaction of 8 b , 9 b 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 .