OICC Press Iranian Journal of Catalysis 2345-4865 8 1 2024 02 03 Montmorillonite KSF as a very efficient heterogeneous catalyst for the synthesis of 5-substituted 1H-tetrazoles EN Rahman Hosseinzadeh Department of Organic Chemistry, Factually of Chemistry, University of Mazandaran, Babolsar, Iran. Zahra Lasemi Department of Chemistry, Firoozkooh Branch, Islamic Azad University, Firoozkooh, Iran. Farzaneh Maliji Department of Organic Chemistry, Factually of Chemistry, University of Mazandaran, Babolsar, Iran. Journal Article 2024 02 03 Montmorillonite KSF has been used as an effective and non-toxic heterogeneous catalyst for one-pot synthesis of 5-substituted 1H-tetrazoles via [3+2] cycloaddition of sodium azide with a wide variety of nitriles. The reaction afforded high yields of the desired products in a short reaction time under mild reaction conditions. The catalyst can be recovered by simple filtration and reused for more consecutive trials without a significant decrease in activity. To avoid using toxic catalyst and catalyst recycling make this synthesis a truly green procedure.