Silica-supported perchloric acid and potassium bisulfate as reusable green catalysts for nitration of aromatics under solvent-free microwave conditions

<p>Silica-supported perchloric acid and bisulfate (SiO<sub>2</sub>/HClO<sub>4</sub> and SiO<sub>2</sub>/KHSO<sub>4</sub>) have been developed as reusable green catalysts for nitration of aromatic compounds using NaNO<sub>2</sub> in acetonitrile medium under conventional and solvent-free microwave conditions. The reaction times under microwave irradiation are significantly shorter than conventional method even though the yields obtained in microwave-assisted reactions are comparable with those obtained under reflux conditions.</p>