Catalyst‐free Synthesis of 5‐Arylimidazo[1,2‐c]quinazoline Derivatives in Ionic Liquids

Abstract

The reaction of 2‐(4,5‐diphenyl‐1H‐imidazol‐2‐yl)aniline and aromatic aldehyde was treated in ionic liquids under catalyst‐free condition and gave dehydrogenated 5‐aryl‐2,3‐diphenylimidazo[1,2‐c]quinazolines. The same reaction gave un‐aromatized 5‐aryl‐2,3‐diphenyl‐5,6‐dihydroimidazo[1,2‐c]quinazoline derivatives while it was controlled in an inert gas. This procedure approach to imidazo[1,2‐c]quinazolines has the advantages of milder reaction conditions, one‐pot, catalyst free, high yields, and environmentally benign.

Recent Approaches for the Synthesis of Imidazoquinazolines and Benzimidazoquinazolines

“…Imidazo[1,2-c] quinazolines (12a-l) can be prepared via one-pot, catalyst-free, and environment-friendly synthesis using ionic liquids as a solvent in excellent yields by the reaction of imidazolyl anilines (10a-g) with various aromatic aldehydes (11a-g) [43]. The formation of imidazo [1,2-c]quinazoline through oxidative coupling catalyzed by AgOTf was studied by Wu et al [44].…”