Heterogeneously Catalyzed Pechmann Condensation Employing the Tailored ZnTiO NPs: Synthesis of Coumarin.

A novel heterogeneous catalytic method was developed for the synthesis of coumarin and its derivatives using the Ti(IV)-doped ZnO matrix forming catalyst ZnTiO having a high surface area and good Lewis acidity. The catalyst shows high activity toward a broad spectrum of the substituted phenols with β-ketoesters such as ethyl acetoacetate, ethyl butyryl acetate, ethyl benzoyl acetate, and so forth in good yields over short reaction times during the synthesis of coumarins. The methodology was further extended for the synthesis of ayapin molecules. The catalyst also shows recycle activity up to seven cycles with very good stability.