4-Chloro-1-methyl­indoline-2,3-dione

The title mol­ecule, C₉H₆ClNO₂, is essentially planar; the maximum deviation of the indoline ring system is 0.027 (3) Å and the substituents do not deviate by more than 0.075 (2) Å from this plane. Inter­molecular C—H...O hydrogen bonds consolidate the crystal structure.