A green, efficient and recoverable CeO2/MWCNT nanocomposite catalyzed click synthesis of pyridine-3-carboxamides

A facile, green and environmentally-friendly protocol for the preparation of ceria doped multi-walled carbon nanotubes (2.5%CeO2/MWCNTs) composite catalysts are developed. The synthesized catalyst materials have been characterized by using P-XRD, SEM, TEM and BET analysis. Further, the composite was utilized as a highly efficient and reusable heterogeneous nano-catalyst for the synthesis of pyridine-3-carboxamide derivatives by multicomponent condensation of acetoacetanilide, ammonium acetate, substituted aromatic aldehyde and ethyl cyanoacetate via one-pot reaction under ethanol solvent conditions at R.T. The remarkable advantages of this green protocol exhibits operational simplicity, easy workup procedure, inexpensive, evading of toxic solvents, shorter reaction times (<= 15 mins), excellent yields and also avoidance of column chromatography. Furthermore, the catalyst was recyclable and reusability endured for a minimum of six consecutive cycles without significant loss in the catalytic activity.