The role of phosphotungstic acid in enhancing the catalytic performance of UiO-66 (Zr) and its applications as an efficient solid acid catalyst for coumarins and dihydropyrimidinones synthesis
Fares T. Alshorifi, Dina E. Tobbala, Salah M. El‐Bahy, Mohamed A. Nassan, Reda S. Salama
Abstract
In recent study, we report a facile and easy technique for the synthesis phosphotungstic acid (PTA) with different weight contents (10, 25, 50 and 75 wt%) loaded on UiO-66 (Zr) as efficient and reusable catalysts for the preparation of coumarin and dihydropyrimidinones derivatives. The structural and textural properties of the prepared catalysts were characterized through XRD, FT-IR, TGA, BET, TEM, SEM, non-aqueous potentiometric titration and FT-IR of chemisorbed pyridine. 50.0 wt% of PTA/UiO-66 (Zr) catalyst showed the highest surface acidity (Ei = 578.5 mV) and highest catalytic performance toward the preparation of 7-hydroxy-4-methyl coumarin (97.8%) and 3, 4-dihydropyrimidinones (94.7%).