4-Chloro-3-fluoro-2-methyl-aniline-pyrrolidine-2,5-dione (1/1).

Chlorination of 3-fluoro-2-methyl-aniline with N-chloro-succinimide gave one major regioisomer whose structure was determined by X-ray crystallography. The product was found to have cocrystallized with succinimide, giving the title compound, C(7)H(7)ClFN·C(4)H(5)NO(2). The crystal structure is stabilized by N-H⋯O hydrogen-bonding and π-π stacking inter-actions with a centroid-centroid distance of 3.4501†(8)†à .