Nano copper(II) oxide catalyzed four-component synthesis of functionalized benzo[a]pyrano[2,3-c]phenazine derivatives

An efficient one-pot quantitative procedure for the preparation of functionalized benzo[a]pyrano[2,3-c]phenazine derivatives from four-component reaction of 2-hydroxynaphthalene-1,4-dione, o -phenylenediamine, aldehydes, and malononitrile in the presence of nano CuO as the catalyst has been developed. The copper(II) oxide nanoparticles can be recovered and reused several times without loss of its activity.