Predominant ortho-selective mononitration of low-melting and liquid phenols and hydroxycoumarins in moderate to high yields has been accomplished upon grinding with solid cerium (IV) ammonium nitrate (CAN). Microwave-assisted expeditious CAN-mediated nitration of relatively high melting phenols and hydroxycoumarins with high efficiency and selectively under solvent-free conditions has been also developed to address the problems of sluggishness and low yield for these reluctant substrates.
AbstractStarting from readily available 2-naphthol, aldehydes, aryl and alkylamines, a variety of Betti bases were efficiently synthesized utilizing a catalytic amount of cerium (IV) ammonium nitrate (CAN) at room temperature. This protocol has advantages of high yield, mild reaction conditions, no environmental pollution, diversity of reactants and simple work up procedure.