A rapid synthesis of quinoxalines by using Al₂O₃–ZrO₂ as heterogeneous catalyst

Abstract

In this study, we present a highly efficient and environmentally benign protocol for synthesizing biologically important quinoxaline derivatives. The synthesis involves the reaction of 1,2-diamines with substituted phenacyl bromides or benzil, taking place at room temperature in N,N-dimethylformamide (DMF) solvent. The reaction is facilitated by a bifunctional heterogeneous catalyst composed of Al₂O₃–ZrO₂ binary metal oxide. Our method offers numerous advantages, including excellent product yield, renewable catalytic conditions, minimal catalyst usage, safer chemistry, short reaction time, and a simple work-up procedure. To determine the chemical structure of the synthesized derivatives, we employed characterization techniques such as nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS). Additionally, the Al₂O₃–ZrO₂ catalyst was characterized using X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDAX), and thermogravimetric analysis (TGA).

Graphical Abstract

Keywords:

• Al₂O_3–ZrO₂
• cyclocondensation
• quinoxaline
• recyclable

Acknowledgements

We are very much thankful to Chhatrapati Shahu Maharaj Research, Training and Human Development Institute (SARTHI), Pune for Junior Research Fellowship.

Disclosure statement

No potential conflict of interest was reported by the author(s).