3′,7′,7′-Trimethyl-1′-phenyl-5′,6′,7′,8′-tetra­hydro­spiro­[indoline-3,4′-(1H,4H-pyrazolo­[3,4-b]chromene)]-2,5′-dione

The title spiro­oxindole compound, C(26)H(23)N(3)O(3), was prepared by the reaction of isatin, 3-methyl-1-phenyl-2-pyrazolin-5-one and 5,5-dimethyl­cyclo­hexane-1,3-dione in an ethanol solution. The fused cyclo­hexene ring adopts an envelope conformation. The dihedral angle between the aromatic and pyrazoline rings is 23.70 (8)°. An intra­molecular C—H⋯O inter­action occurs. The crystal structure is stabilized by N—H⋯N hydrogen-bonding inter­actions, leading to a zigzag chain along the b axis.