An efficient one-pot synthesis of polyhydroquinoline derivatives via Hantzsch condensation using heterogeneous catalyst under solvent-free conditions

An efficient Hantzsch condensation of polyhydroquinoline derivatives was reported via a fourcomponent coupling reaction of aldehydes, dimedone, ethyl acetoacetate and ammonium acetate in the presence of HClO 4 -SiO 2 under solvent-free conditions. Operational simplicity, use of an economically convenient catalyst, high yield, short reaction times are the key features of this protocol.