ZINC BENZENESULFONATE-PROMOTED ECO-FRIENDLY AND EFFICIENT SYNTHESIS OF 1-AMIDOALKYL-2-NAPHTHOLS

A three-component, one-pot condensation of 2-naphthol, aldehydes, and amides catalyzed by zinc benzenesulfonate gives 1-amidoalkyl-2-naphthols in good yields at 80 degrees C under solvent-free conditions. The catalytic activities of zinc benzenesulfoante and 12 other metal benzenesulfonates were compared. After the reaction, zinc benzenesulfoante can be recycled several times without distinct loss of catalytic activity.