Titanium Dioxide Nanoparticles Catalyzed Synthesis of Hantzsch Esters and Polyhydroquinoline Derivatives

1,4-Dihydropyridine and polyhydroquinoline derivatives have been prepared efficiently in a one-pot synthesis via Hantzsch condensation using nanosized titanium dioxide as a heterogeneous catalyst. The present methodology offers several advantages such as excellent yields, short reaction times (30-120 min), environmentally benign, and mild reaction conditions. The catalyst can be readily separated from the reaction products and recovered in excellent purity for direct reuse.

Graphical abstractTiO2 nanoparticles are used as an efficient catalyst for the preparation of 1,4-dihydropyridines (1,4-DHPs) and polyhydroquinolines in ethanol. The catalyst can be recovered and reused for several times and the product yield is high in this system.Figure optionsDownload full-size imageDownload as PowerPoint slide