Solvent‐Free Synthesis of 4<i>H</i>‐Pyrido[1,2‐<i>a</i>]pyrimidin‐4‐ones Catalyzed by BiCl₃: A Green Route to a Privileged Backbone

Abstract

Abstract An extensive array of 4 H ‐pyrido[1,2‐ a ]pyrimidin‐4‐ones have been synthesized from commercially available 2‐aminopyridines and β‐oxo esters with excellent yields under solvent‐free conditions. The reaction, catalyzed by cheap and nontoxic BiCl 3 , proceeds with short reaction times under mild conditions and normal atmosphere. Only water and alcohol are formed as co‐products in this green reaction.