Synthesis of Some Biginelli-type Products: Nano Alumina Sulfonic acid (NASA) Catalyzed under Solvent-free Condition

Biginelli-type reaction was developed by means of a three-component condensation of analdehyde, ethyl acetoacetate, urea or thiourea and nano alumina sulfonic acid (Al2O3-SO3H)(NASA) as catalyzed. It is carried out under different conditions. In all conditions, the desiredproducts are obtained in high yields after relatively short reaction times. Nevertheless, thereactions proceeded faster and in higher yields when they were carried out under solvent-free at120 °C. Improving product yields and reaction time, NASA was used in a catalytic amount(0.027 mol%). An amount of catalyst used in these reactions is far less than reported (15 mol%).The rate of the reaction was also 24 times faster than the previous rate reported by Shaterian andco-workers by the same yield. Scanning electron microscopy (SEM) and transmission electronmicroscopy (TEM) techniques are used to characterize the microstructural of NASA. Finally, themechanism of this reaction was studied.