Ethyl 2-amino-7,7-dimethyl-2′,5-dioxo­spiro­[5,6,7,8-tetra­hydro-4H-chromene-4,3′(2′H)-1H-indole]-3-carboxyl­ate

In the mol­ecule of the title compound, C(21)H(22)N(2)O(5), the indole system and the spiro-pyran ring are almost planar [maximum deviations of 0.0447 (17) and 0.0781 (17) Å, respectively]; the dihedral angle between them is 84.6 (3)°. The remaining six-membered ring adopts a twisted conformation. Intra­molecular N—H⋯O hydrogen bonds occur. In the crystal structure, intera­molecular N—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules.