Zeolite and sulfated zirconia as catalysts for the synthesis of 5-substituted 1H-tetrazoles via [2+3] cycloaddition of nitriles and sodium azide

The [2+3] cycloaddition between various nitriles and sodium azide proceeds smoothly in the presence of zeolite and sulfated zirconia as effective catalysts, in water and DMF/MeOH, to give the corresponding 5-substituted 1H-tetrazoles in good to high yields. The reaction most probably proceeds through the in situ formation of catalyst azide species, followed by a successive [2+3] cycloaddition with the nitriles. This method has the advantages of high yields, simple methodology and easy work-up. The catalyst can be recovered by simple filtration and reused with good yields.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► [2+3] cycloaddition between various nitriles and sodium azide is investigated. ► We examine the zeolite and sulfated zirconia as catalyst for the preparation of 5-substituted 1H-tetrazoles. ► The advantages of this methodology are high yields, simplicity and easy preparation of the catalyst. ► The catalysts can be recovered for the subsequent reactions and reused.