Four-Component Synthesis of 3-Amino-1-Aryl-5,10-Dioxo-1H-Pyrazolo[1,2-b] Phthalazine-2-Carbonitrile Derivatives Promoted by Potassium Carbonate

Abstract

The one-pot, four-component reaction of phthalic anhydride, hydrazine hydrate, aromatic aldehydes and malononitrile afford 3-amino-1-aryl-5,10-dioxo-1H-pyrazolo[1,2-b]phthalazine-2-carbonitrile derivatives in the presence of potassium carbonate in ethanol under reflux conditions. These conditions offer simplified operation, easy purification, excellent yields and environmentally benign reaction conditions. Also, this method avoids the use of expensive catalysts, toxic solvents and chromatographic separation.