Green approach: Nanocrystalline titania-based sulfonic acid catalyst for the synthesis of piperazinyl-quinolinyl pyran derivatives
Arul Murugesan, Robert M Gengan*, Anand Krishnan
Department of Chemistry, Faculty of Applied Sciences, Durban University of Technology, Durban 4001, South Africa
Adv. Mater. Lett., 2017, 8 (2), pp 128-135
Publication Date (Web): Dec 27, 2016
Copyright © 2019 VBRI Press
A nanocrystalline titania-based sulfonic acid material was prepared, characterized and used as an effective, efficient and re-usable catalyst for the synthesis of 2-amino-4-(2-(4-methylpiperazin-1-yl) quinolin-3-yl)-6-phenyl-4H-pyran-3-carbonitriles and 2-amino-4-(2-(4-methylpiperazin-1-yl)quinolin-3-yl)-6-(pyridin-4-yl)-4H-pyran-3-carbonitrile derivatives under solvent-free conditions. This simple three component one-pot synthesis results in high yield products in 2 hours via conventional heating protocols. The catalyst was characterized by XRD, TEM, SEM, BET and Raman spectroscopy. The catalyst was recycled 5 times and recorded a decrease of 10 % in catalytic activity making it cost effective for large scale production.
Sulfonic-acid catalyst, solvent-free, MCR, knoevenagel condensation.