Three-Component Reaction of 1H-Pyrrole-2,3-diones with Malononitrile and Phthalhydrazide

Base-catalyzed three-component condensation of ethyl 4,5-dioxo-4,5-dihydro-1H-pyrrole-3-carboxylates with malononitrile and phthalhydrazide afforded substituted ethyl 3-amino-2-cyano-2′,5,10-trioxo-5′-phenyl-1′,2′,5,10-tetrahydrospiro[pyrazolo[1,2-b]phthalazine-1,3′-pyrrole]-4′-carboxylates which attract interest for medicinal chemistry. The reaction provides a convenient preparative method of synthesis of previously inaccessible spiro[pyrazolo[1,2-b]phthalazine-1,3′-pyrrole] heterocyclic system.