Dual Role of Choline Azide for One-Pot Synthesis of Quinolines and Quinazolines Using Versatile Magnetic Cu-Oxalate@Fe₃O₄ Catalyst

The present study demonstrates biogenically synthesized copper-oxalate supported on iron oxide (Fe₃O₄) and its implementation for pharmaceutically important quinoline and quinazoline synthesis. The formation of a new catalyst was confirmed by Field emission scanning electron microscope (FE-SEM) and Brunauer–Emmett–Teller (BET) analysis that displayed a spherical shape with a surface area of 18.407 m² g⁻¹, and an active metal concentration of 12.02 w/w%. The dual role of choline azide as a green solvent as well as a nitrogen source is demonstrated and a series of quinoline and quinazoline derivatives were synthesized in good to excellent yield. Importantly, catalyst recyclability, mechanistic investigations, control experiments, and reaction economy highlight the importance of methodology. Graphical Abstract: (Figure presented.)