Structure of an anticonvulsant N-methyl-m-bromophenylsuccinimide. 
3-(3-Bromophenyl)-1-methyl-2,5-pyrrolidinedione, C11H10BrNO2, Mr = 268.11, triclinic P1, a = 11.606 (2), b = 11.832 (2), c = 10.370 (2) A, alpha = 101.84 (1), beta = 107.76 (1), gamma = 118.28 (2) degrees, V = 1085.7 (5) A3, Z = 4, Dx = 1.640 Mg m-3, lambda(Cu K alpha) = 1.54178 A, mu = 5.04 mm-1, F(000) = 536, room temperature, final R = 0.061 for 2971 observed reflections with I greater than 3 sigma(I) (of 3743 unique data).  The only slight differences in conformation of the two independent molecules are in the inclination of the phenyl and five-membered rings.  The torsion angle C4-C1-C11-C12 is -115.4 (4) degrees in molecule I and -131.6 (4) degrees in molecule II.  The five-membered imide ring has the open-envelope conformation in molecule I [the deviation of C11 from the plane N11-C41-C21-C31 is -0.117 (3) A] and the twist conformation in molecule II [the deviations of C12 and C22 from the plane N12-C42-C32 are 0.117 (1) and -0.064 (1) respectively].