Synthesis of selected 5-thio-substituted tetrazole derivatives and evaluation of their antibacterial and antifungal activities

Several 5-thio-substituted tetrazole derivatives were efficiently syn- thesized by a three-step process. The substituted tetrazol-5-thiol, namely, 1-ben- zyl-1H-tetrazole-5-thiol (2) was prepared by refluxing commercially available benzyl isothiocyanate (1) with sodium azide in water. The second step was the synthesis of 1-benzyl-5-((3-bromopropyl)thio)-1H-tetrazole (3) by thioalkyla- tion of tetrazole-5-thiol 2 with 1,3-dibromopropane in tetrahydrofuran. Finally, the 5-thio-substituted tetrazole derivatives 4a-i were prepared by condensation of 3 with the corresponding amine or thiol. The structures of the newly synthe- sized compounds were characterized by NMR, LC/MS/MS, IR spectral data and elemental analysis. All the synthesized compounds were screened for their antibacterial and antifungal activities.