Nanocrystalline TiO_2-HClO_4 catalyzed three-component preparation of derivatives of 1-amidoalkyl-2-naphthol, 1-carbamato-alkyl-2- naphthol, 1-(α-aminoalkyl)-2-naphthol, and 12-aryl-8,9,10,12- tetrahydrobenzo[a]-xanthen-11-one

摘要

1-Amidoalkyl-2-naphthols, 1-carbamatoalkyl-2-naphthols, and 1-(α-aminoalkyl)-2-naphthols have been prepared by three-component reaction of 2-naphthol, aromatic aldehydes, and NH compounds, i.e. amides, carbamates, and secondary amines, respectively, in the presence of a catalytic amount of nanocrystalline TiO_2-HClO_4. In addition, 12-aryl-8,9,10,12-tetrahydrobenzo[a]-xanthen-11-one derivatives have been synthesized by reaction of 2-naphthol, aromatic aldehydes, and dimedone in the presence of the same nano catalyst. These reactions were studied under solvent-free conditions. This white acidic heterogeneous catalyst is very stable under the reaction conditions and was reused several times without significant loss of activity.