The Synergy of Combined Use of DMSO and Bronsted Acid (Ionic Liquid) as a Catalyst Part I: Efficient Niementowski Synthesis of Modified Quinazolinones

A new rapid and versatile approach using Ionic liquid/DMSO as a chemical reagent for the synthesis of fused heterocyclic compounds in a highly efficient way is described. This method offers the advantages of proceeding in neutral conditions, giving high to excellent isolated yields (83–92%) for Niementowski synthesis with easy workup procedure. The inherent Bronsted acidity of ionic liquid and high polarity of both IL and DMSO resulted in a significant enhancement in the reaction rate.