nanosilica molybdic acid: synthesis, characterization and application as a green and reusable catalyst for the pechmann condensation

Nanosilica molybdic acid (sma nps) was founded as an efficient and recyclable nanocatalyst for the synthesis of coumarin derivatives in excellent yields with good purity. nano-sma as a new solid acid was characterized by x-ray fluorescence, x-ray diffraction, energy-dispersive x-ray analyzer, transmission electron microscopy and fourier transform infrared spectroscopy. coumarin derivatives were obtained via the pechmann condensation reaction of phenols and β-ketoesters at 80 °c under solvent-free conditions. the main advantages of the present procedure are high yields, shorter reaction time and green chemistry procedure, simple work-up and inexpensive and reusability of the catalyst.