ClO4 −/Zr-MCM-41 nanoparticles prepared at mild conditions: a novel solid acid catalyst for the synthesis of polyhydroquinolines

One-pot four-component reaction of aldehydes, dimedone, ethyl cyanoacetate or ethyl acetoacetate and ammonium acetate was studied in the presence of perchlorated Zr-MCM-41 (ClO4 −/Zr-MCM-41) nanoparticles for the synthesis of dihydropyridines. Zr-MCM-41 nanoparticles with various molar ratios of Si/Zr were synthesized by sol–gel method under mild conditions, and then ClO4 −/Zr-MCM-41 samples with different calcination temperatures were prepared and characterized by XRD, FT-IR and SEM techniques. The characterization results show the presence of perchlorate in the mesostructure of Zr-MCM-41 and the catalytic performance experiments show that ClO4 −/Zr-MCM-41 with Si/Zr molar ratio of 25 and calcinations temperature of 300 °C has the best catalytic activity. The catalyst can be recovered easily and reused many times with moderate decrease in activity.