Abstract

Background: The imidazo[1,2-a]pyridine ring has been widely studied by medicinal chemists and displays great pharmaceutical potential.

Methods: In a view to prepare a library of new molecules including an imidazo[1,2-a]pyridine scaffold, as original fragments for the conception of novel anti-protozoal compounds, the Sonogashira crosscoupling reaction between 3-halogenoimidazo [1,2-a]pyridines and phenylacetylene was studied.

Results: From 3-iodoimidazo[1,2-a]pyridine, chosen as an optimal substrate for conducting the reaction at room temperature in 2 hours, a variety of terminal alkynes was involved into the reaction, leading to a series of 16 new 3-phenyethynylimidazo [1,2-a]pyridines in satisfying to good yields (50-82%) and 4 additional derivatives in moderate yields (30-40%).

Conclusion: Such synthetic approach appears efficient for the rapid synthesis of imidazopyridine chemical libraries. The corresponding derivatives will next be evaluated for their anti-infective properties.

Keywords: 3-halogenoimidazo[1, 2-a]pyridines, Sonogashira cross-coupling reaction, 3-alkynylimidazoimidazo[1, 2-a]pyridine.

Graphical Abstract