3,3,6,6-Tetra­methyl-9-(2-oxo-1,2-dihydro­quinolin-3-yl)-1,2,3,4,5,6,7,8-octa­hydro-9H-xanthene-1,8-dione

In the title compound, C₂₆H₂₇NO₄, the central ring of the xanthene moiety is planar and the two outer rings are in half-boat conformations. The mol­ecular packing in the crystal structure is stabilized by N—H...O and C—H...O hydrogen bonds in addition to van der Waals forces.