Crystal structure of 5-chloro-1,3-bis­[2-(2-oxo-1,3-oxazolidin-3-yl)eth­yl]-1H-benz­imidazol-2(3H)-one

In the title compound, C(17)H(19)ClN(4)O(5), the benzimidazole fused-ring system is essentially planar, the maximum deviation from the mean plane being 0.06 (1) Å. Both oxazolidine rings are nearly planar, the maximum deviations from the mean planes are 0.071 (13) and 0.070 (10) Å. The dihedral angle between the mean planes of the oxazolidine rings is 69.9 (7)°. The benzimidazole mean plane makes the dihedral angles of 43.9 (6) and 45.6 (6)° with the two oxazolidine rings. In the crystal, the mol­ecules are linked together by weak C—H⋯O hydrogen bonds building zigzag tapes running along the c axis. The Cl atom is split over two positions with an occupancy ratio of 0.567 (7):0.433 (7). This means that the reaction yields two isomers, A and B; the A component has the Cl-atom substituent in the 5-position of the benzimidazolone ring and the B component has the Cl atom in the 6-position. The two isomers form the disordered co-crystal, with a nearly half Cl atom in each of them, as indicated by the occupancy ratio. The crystal structure was refined as an inversion twin.