Dimethyl 2-[(acridin-9-yl)methyl­idene]malonate

In the title compound, C₁₉H₁₅NO₄, the acridine system is essentially planar (r.m.s. deviation = 0.015 Å). The crystal packing exhibits π–π inter­actions between pairs of centrosymmetric mol­ecules, one of them between the central heterocyclic rings and others between the outer benzene rings of the acridine systems, with centroid–centroid distances of 3.692 (1) and 3.754 (1) Å, respectively. These pairs are further linked by additional π–π inter­actions along the a-axis direction through one of the two outer benzene ring of neighboring mol­ecules, with a centroid–centroid distance of 3.642 (2) Å.