Al2(SO4)3 IS AN EFFICIENT AND MILD ACID CATALYST FOR THE ONE-POT, FOUR-COMPONENT SYNTHESIS OF POLYHYDROQUINOLINE

摘要

Aluminium sulfate has mild acidity, yet the acidity of aluminium sulfate is not taken advantage of in organic synthesis. Here, we utilized aluminium sulfate for the first time in a multicomponent reaction for the synthesis of polyhydroquinoline. A four-component one-pot synthesis of polyhydroquinoline was carried out by condensing dimedone, aromatic aldehyde, ethyl acetoacetate, and ammonium acetate using a catalytic amount of aluminium sulfate (10%) refluxed in ethanol. The present protocol using aluminium sulfate a mild solid catalyst has several merits, such as low cost, high yield, and shorter reaction time, with no byproducts.