A facile synthesis of quinoxalines by using SO₄²⁻/ZrO₂-TiO₂ as an efficient and recyclable heterogeneous catalyst

Abstract

Quinoxaline derivatives have been synthesized in good to excellent yields by the cyclocondensation reaction of o-pheneylenediamine with substituted phenacyl bromides/benzil in the presence of SO₄²⁻/ZrO₂-TiO₂ as an efficient and heterogeneous catalyst. The catalyst can be recovered up to five catalytic cycles without significant loss in catalytic activity. The reported SO₄²⁻/ZrO₂-TiO₂ catalyst has been thoroughly characterized by using infrared spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and powder X-ray diffraction (XRD). Here, we have used ethanol as a green solvent in this cyclocondensation. This new method has several advantages, such as excellent yields, short reaction time, nontoxic, and easily recoverable catalyst.

Graphical Abstract

Keywords:

• SO₄²⁻/ZrO₂-TiO₂
• quinoxalines
• recyclable
• heterogeneous catalyst
• cyclocondensation

Disclosure statement

The authors declare no conflict of interest.