An efficient one-pot, convenient catalysis for the synthesis of 5-substituted-1H-tetrazoles is reported. The [3+2] cycloaddition involves various nitriles, sodium azide in refluxing DMF and AgNO3 as catalyst to give corresponding 5-substituted-1H-tetrazoles in good to excellent yields. It is expected that the reaction proceeds via in situformation of a silver azide species, which participates in coordination
Various carbinol substituted benzimidazoles, for example certain .alpha.-alkyl-.alpha.-hydroxybenzyl substituted-1-sulfonylbenzimidazole compounds, are dehydrated to provide alkylidenylmethyl substituted benzimidaloles which are useful as antiviral agents.