A highly efficient heterogeneous copper-catalyzed cascade reaction of 2-halobenzoic acids and amidines leading to quinazolinones†
Abstract
The heterogeneous cascade reaction of 2-halobenzoic acids and amidines was achieved in DMF at 60 °C in the presence of 10 mol% of MCM-41-immobilized tridentate nitrogen copper(I) complex [MCM-41-3N–CuI] using Cs2CO3 as base, yielding a variety of quinazolinone derivatives in good to excellent yields. This heterogeneous copper catalyst can be easily prepared from commercially available and inexpensive reagents, and recovered by a simple filtration of the reaction solution and reused for at least 10 times without any decreases in activity.