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

Abstract

Biginelli-type reaction was developed by means of a three-component condensation of an<br />aldehyde, ethyl acetoacetate, urea or thiourea and nano alumina sulfonic acid (Al2O3-SO3H)<br />(NASA) as catalyzed. It is carried out under different conditions. In all conditions, the desired<br />products are obtained in high yields after relatively short reaction times. Nevertheless, the<br />reactions proceeded faster and in higher yields when they were carried out under solvent-free at<br />120 °C. Improving product yields and reaction time, NASA was used in a catalytic amount<br />(0.027 mol%). An amount of catalyst used in these reactions is far less than reported (15 mol%).<br />The rate of the reaction was also 24 times faster than the previous rate reported by Shaterian and<br />co-workers by the same yield. Scanning electron microscopy (SEM) and transmission electron<br />microscopy (TEM) techniques are used to characterize the microstructural of NASA. Finally, the<br />mechanism of this reaction was studied.<br /><br />