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

Several 5-thio-substituted tetrazole derivatives were efficiently synthesized by a three-step process. The substituted tetrazol-5-thiol, namely, 1-benzyl-1H-tetrazol-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]tetrazole (3) by thio alkylation of tetrazol-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 synthesized 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.