Three-component spiro heterocyclization of 1H-pyrrole-2,3-diones with malononitrile and pyrazolones. Crystal and molecular structure of a spiro[pyrano[2,3-c]-pyrazole-4,3′-pyrrole]

5-Phenyl-1H-pyrrole-2,3-diones reacted with malononitrile and 1H-pyrazole-5(4H)-ones to give substituted 6-amino-5-cyano-2′-oxo-5′-phenyl-1′,2′-dihydro-1H-spiro[pyrano[2,3-c]pyrazole-4,3′-pyrroles]. The crystal and molecular structures of ethyl 6-amino-1,1′-dibenzyl-5-cyano-3-methyl-2′-oxo-5′-phenyl-1′,2′-dihydro-1H-spiro[pyrano[2,3-c]pyrazole-4,3′-pyrrole]-4′-carboxylate were determined by X-ray analysis.