ZnO-Nanoparticles: Efficient and Reusable Heterogeneous Catalyst for One-Pot, Four-Component Synthesis of 2H-indazolo(2,1-b) phthalazine-triones

ZnO nanoparticles as efficient and reusable catalyst for the synthesis of 2H indazolo(2,1-b)phthalazine-triones from the one-pot, four-component reaction of arylaldehydes, hydrazine monohydrate, phthalic anhydride, dime done under solvent-free conditions with short reaction times is described. The ZnO nanoparticles can be reused several times without significant loss of its catalytic activities. (author)