An Efficient and Green Procedure for the Synthesis of 2,4,6‐Triarylpyridines Using PPA‐SiO2 as a Reusable Heterogeneous Catalyst Under Solvent‐Free Conditions

Abstract

Silica gel‐supported polyphosphoric acid (PPA‐SiO2) 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.