Cu(OH)x-clay catalyst promoted synthesis of 4,5-dihydro-1,2,4-oxadiazole at room temperature

Abstract

An easy and efficient scheme is described and designed for the preparation of 4,5-dihydro-1,2,4-oxadiazole using recyclable Cu(OH)x-clay heterogeneous catalyst at room temperature. The cycloaddition reaction is carried out between imine and oxime using an easy protocol where nitrile oxides are produced in situ from aldoximes and reacted with imines to form 1,2,4-oxadiazolines in good yield and tremendous purity. Cu(OH)x-clay catalyst shows excellent catalytic activity for the formation of 1,2,4-oxadiazole. This technique is practically uncomplicated, inexpensive, and excellent with a wide range of functional group tolerance to generate structurally different 1,2,4-oxadiazoles. The prepared catalyst was investigated by X-ray diffraction and scanning electron microscopy techniques. The final products of the synthesized compound were characterized by Fourier transform infrared, mass, and nuclear magnetic resonance spectroscopies.

Keywords

• cycloaddition
• green chemistry
• heterogeneous catalyst
• imines
• oxadiazoles