ZrOCl2.8H2O/SiO2: An efficient and recyclable catalyst for the preparation of coumarin derivatives by Pechmann condensation reaction

Silica gel supported zirconyl chloride octahydrate was found to be an efficient and recyclable catalyst for the synthesis of a series of biologically important molecules in high turnover numbers and rates. Several substituted coumarins can be prepared in high yield and purity by direct reaction of β-keto esters and phenol derivatives in the presence of a catalytic amount of ZrOCl2.8H2O/SiO2 as Lewis acid and at ambient temperature under solvent-free conditions. This method which is called Pechmann condensation is a very easy and a rapid reaction for the synthesis of coumarin derivatives.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► ZrOCl2.8H2O/SiO2: an efficient catalyst for synthesis of coumarins. ► Synthesis of coumarin compounds by Pechmann condensation. ► Study of supporting of ZrOCl2.8H2O on SiO2. ► Study of reusability of the ZrOCl2.8H2O/SiO2 in synthesis of coumarins. ► Comparison of the results for preparation of coumarins with other catalysts.