arylaminotetrazoles : via [2+3] cycloaddition of nitriles and sodium azide via solid acid catalysis

The [3+2] cycloaddition between various nitriles and sodium azide proceeds smoothly in the presence of zeolite and sulfated Zircona as effective catalyst and in the water and DMF/MeOH, to give the corresponding arylaminotetrazoles in good to high yields. The reaction most probably precedes through the in situ formation of a catalyst azide species, followed by a successive [3+2] 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 in good yields