Highly efficient three-component synthesis of 5-substituted-1H-tetrazoles from aldehydes, hydroxylamine, and tetrabutylammonium azide using doped nano-sized copper(I) oxide (Cu2O) on melamine-formaldehyde resin

A simple and facile one-pot three-component synthesis of 5-substituted 1H-tetrazole derivatives from aldehydes catalyzed by doped nano-sized Cu2O on melamine-formaldehyde resin (nano-Cu2O-MFR) is described. In this protocol, treatment of structurally diverse aldehydes, hydroxylamine hydrochloride and tetrabutylammonium azide (TBAA) as an azide source in the presence of nano-Cu2O-MFR as an efficient heterogeneous nano-catalyst affords the corresponding 5-substituted 1H-tetrazoles in good to excellent yields. The influence of different parameters on the progress of reaction was studied. The nano-Cu2O-MFR is a cheap and stable nano-catalyst that could be easily prepared, recycled and reused for many consecutive reaction runs without significant decrease in its activity.