N-Butanoyl-N-(3-chloro-1,4-dioxonaph-thalen-2-yl)butanamide.

In the title compound, C18H18ClNO4, the imide group with its two alkyl substituents is approximately perpendicular to the plane of the naphtho-quinone ring system [dihedral angle = 78.5 (1)°]. Further, the imide carbonyl groups are oriented in an anti sense. In the crystal, the substituted naphtho-quinone rings form π-π stacks in the a-axis direction [perpendicular centroid-centroid distance = 3.209 (2) Šand slippage = 4.401 Å].