An efficient and green procedure for the synthesis of 2,4,6- triarylpyridines using PPA-SiO 2 as a reusable heterogeneous catalyst under solvent-free conditions

Abstract

Silica gel-supported polyphosphoric acid (PPA-SiO 2) was found to be highly efficient, eco-friendly and recyclable heterogeneous catalyst for the synthesis of 2,4,6-triarylpyridines through one-pot three-component reaction of acetophenone, aryl aldehydes, and ammonium acetate under solvent-free conditions. This method has several advantages, such as simple procedure with an easy work-up, short reaction times, and high yields. Furthermore, the catalyst could be recycled after a simple work-up, and used at least three times without substantial reduction in its catalytic activity. © 2012 Hindawi Publishing Corporation.