Synthesis of Starch Derived Sulfonated Carbon-based Solid Acid as a Novel and Efficient Nanocatalyst for the Synthesis of Dihydropyrimidinones

Abstract

Novel Carbon-based solid-acid nanocatalyst (SCP-SO3H) has been synthesized via one-step hydrothermal carbonization and sulfonation of starch, citric acid, and p-toluenesulfonic acid at 180 °C in a sealed autoclave. The novel nanocatalyst had an acidity of 6.4 mmol/g which was characterized by IR, EDX, TEM, FESEM, and XRD analyses. The catalytic activity of the carbonaceous material as an efficient and reusable catalyst was investigated by the condensation reaction of ethyl acetoacetate, aldehyde and urea for the synthesis of Dihydropyrimidinones. The condensation reaction was carried out under solvent-free conditions at 100 °C to produced Dihydropyrimidinones in good to high yields. The mild conditions, eco-friendly, excellent yields, short reaction times and using an inexpensive and reusable catalyst are important features of this method.