Zr-Based Metal-Organic Framework as an Efficient Nanocatalyst for Three-Component Synthesis of Quinazolin-4(1H)-one Derivatives

The framework of UiO-66 (Zr6O4(OH)4(bdc)6; bdc2-= 1,4-benzenedicarboxylate), a zirconium-based MOF with very high surface area, is constructed of Zr6O4(OH)4(O2CR)12 clusters inwhich the μ3-O and μ3-OH ligands originate from water present during the synthesis and thecarboxylate groups are part of the bdc2- ligands linking the clusters together [1]. The remarkablethermal and chemical stability of this Zr4+ based MOF material prompted us to use thisMOF for the first time as a catalyst for the synthesis of 2,3-dihydroquinazilin-4(1H)-ones [2,3], employing three-component reactions of isatoic anhydride with primary amines (or ammoniumacetate) and aldehydes under thermal solvent-free conditions (moderate to goodyields) (Fig. 1). The catalyst is stable under the reaction conditions as confirmed by comparisonof the powder XRD and FT-IR of the fresh and reused catalyst.