Kröhnke reaction in aqueous media: one-pot clean synthesis of 4′-aryl-2,2′:6′,2″-terpyridines

A clean aqueous Kröhnke reaction process has been accomplished via a one-pot procedure of 2-acetylpyridine with aromatic aldehyde and ammonium acetate under microwave irradiation or conventional heating conditions. This method is convenient, economic and environmental friendly.