Mild preparation of hydroxyl naphthalene-1,4-dione derivatives with nano copper(II) oxide as catalyst under ambient and solvent-free conditions

An efficient one-pot quantitative procedure for the preparation of hydroxyl naphthalene-1,4-dione derivatives from three-component condensation reaction of aromatic aldehydes, aromatic amines, and 2-hydroxynaphthalene-1,4-dione in the presence of nano copper(II) oxide as catalyst under mild, ambient and solvent-free conditions is described. Simple procedure, high yields, short reaction time and an environmentally benign method are advantages of these protocols. The copper(II) oxide nanoparticles can be recovered and reused several times without loss of its activity.