6-Hy­droxy-1,2-dihydro-4H-pyrrolo­[3,2,1-ij]quinolin-4-one

The mol­ecule of the title compound, C₁₁H₉NO₂, is essentially planar [r.m.s. deviation of the non-H atoms = 0.056 (1) Å]. In the crystal, strong O—H...O hydrogen bonds form zigzag chains along the b axis. The mol­ecules form stacks along the a axis due to π–π inter­actions, the shortest distance between the centroids of the benzene and pyridinone rings being 3.6146 (7) Å.