Ethyl 2-oxo-3-(3-phthalimidoprop-yl)-2,3-dihydro-1H-1,3-benzimidazole-1-carboxyl-ate.

In the title compound, C21H19N3O5, the phthalimide and benzamidazole ring systems are linked by a propyl chain. The benzamidazole unit also carries an eth-oxy-carbonyl substit-uent. The phthalimido and benzimidazole ring systems are essentially planar, the maximum deviations from their mean planes being 0.008 (2) and 0.020 (2) Å, respectively. The two ring systems are almost orthogonal to one another, making a dihedral angle of 82.37 (8)°. In the crystal, C-H⋯O hydrogen bonds and C-H⋯π contacts stack the mol-ecules along the b axis.

1-Allyl-5-nitro-1H-benzimidazol-2(3H)-one.

The benzimidazolone residue in the title mol-ecule, C10H9N3O3, is almost planar, with the largest deviation from the mean plane being 0.016 (2) Šfor the C atom linked to the nitro group. This plane is nearly perpendicular to the 1-allyl chain as indicated by the C-N-C-C torsion angle of 90.9 (3)°. The fused-ring system makes a dihedral angle of 5.6 (3)° with the nitro group, leading to a synperiplanar conformation. In the crystal, zigzag supra-molecular chains are formed along the a axis by N-H⋯O hydrogen bonds.