Microwave-Assisted Erlenmeyer Synthesis of Azlactones Catalyzed by MgO/Al2O3 Under Solvent-Free Conditions

Abstract

MgO/Al2O3 catalyzes the synthesis of azlactone derivatives from condensation reaction of aldehydes (or ketones) with hippuric acid and acetic anhydride as a dehydrating agent under microwave irradiation. The low toxicity, low cost, ease of handling, and high activity of MgO/Al2O3 make this procedure particularly attractive. Also, this catalyst can be easily recovered by decant and can be reused for this condensation five times in succession without considerable loss of its catalytic activity.