Design, Synthesis, and In Vitro Antimicrobial Evaluation of Fused Pyrano[3,2-e]tetrazolo[1,5-c]pyrimidines and Diazepines

A series of novel pyranochromene-containing tetrazoles fused with pyrimidinethiones, pyrimidines, and diazepines 3a-f, 4a-f, and 5a-f were synthesized by condensation of the corresponding tetrazoles 2a-f with carbon disulfide, benzaldehyde, and 4-methoxy phenacyl bromide, respectively. The compound 2a-f was obtained by reaction of pyrano[3,2-c]chromenes 1a-f with sodium azide. The structures of the newly synthesized compounds 2a-f to 5a-f were established on the basis of their elemental analyses, IR, (1)H NMR, (13)C NMR, and mass spectral data. All of the title compounds were subjected to in vitro antibacterial testing against four pathogenic strains and antifungal screening against two fungi. Preliminary results indicate that some of them exhibited promising activities and that they deserve more consideration as potential antimicrobials.