Graphene-supported NiBr2: A highly efficient and reusable catalyst for the Biginelli reaction

ABSTRACTIn this study, the graphene-supported NiBr2 (GNs-NiBr2) was prepared and investigated for three-component condensation reaction of aromatic aldehyde, ethyl acetoacetate and urea (thiourea) to afford corresponding 3,4-dihydropyrimidinones. In 1893, Petro Biginelli reported the first synthesis of 3,4-dihydropyrimidin-2(1H)-one (DHPM) by a one-pot cyclocondensation reaction of benzaldehyde, ethyl acetoacetate and urea under strongly acidic conditions. Furthermore, the graphene-supported NiBr2 (GNs-NiBr2) is highly stable and recyclable for several times without significant loss of its reactivity.