(Z)-3′,6′-Bis(diethylamino)-2-(4-oxopent-2-en-2-ylamino)spiro[isoindoline-1,9′-xanthen]-3-one

In the title compound, C33H38N4O3, the mean planes of the 9H-xanthene unit and spirolactam (nine-atom) core are almost mutually perpendicular at 87.26 (6)°. Intramolecular N—H...O and C—H...N interactions influence the 4-oxopent-2-en-2-ylamino conformation. In the crystal, weak C—H...O hydrogen bonds link the molecules into chains along [001].