Abstract
In the title isoquinoline-1,3,4-trione derivative, C18H9NO5, the five-membered ring of the indane fragment adopts an envelope conformation with the nitrogen-substituted C atom being the flap. The planes of the indane benzene ring and the isoquinoline-1,3,4-trione ring make a dihedral angle of 82.06 (6)degrees. In the crystal, molecules are linked into chains extending along the bc plane via C-H center dot center dot center dot O hydrogen-bonding interactions, enclosing R-2(2)(8) and R-2(2)(10) loops. The chains are further connected by pi-pi stacking interations, with centroid-to-centroid distances of 3.9050 (7) angstrom, forming layers parallel to the b axis.