Abstract
In this study, Keggin-type phosphotungstate-based ionic liquid [HOOCC5H4NH]3PW12O40 was synthetized using nicotinic acid and H3PW12O40 as precursors and characterized via FT-IR, 1H NMR, 13C NMR, XRD, TGA, and DTG analyses. Then, [HOOCC5H4NH]3PW12O40 was utilized as a highly effective and eco-friendly catalyst for the synthesis of xanthenediones through two-component reaction of aldehydes and dimedone under solvent-free conditions at 120 °C. The convenient work-up procedure, mild reaction conditions, high yields, and practically short reaction times were the specific merits of the synthetic method. In addition, the designed ionic liquid was recycled efficiently and reused four times without further decrease in the catalytic ability.
Acknowledgement
We gratefully thank Islamic Azad University, Central Tehran Branch.
Disclosure statement
There are no conflicts of interest.