5-Nitro-1-n-octyl-1H-benzimidazol-2(3H)-one.

The benzimidazolone part of the mol-ecule of the title compound, C(15)H(21)N(3)O(3), is almost planar (r.m.s. deviation = 0.007 Å) with its mean plane aligned at a dihedral angle of 10.4 (3)° with respect to the mean plane of the nitro substituent. In the crystal, two mol-ecules are disposed about a center of inversion, generating an N-H⋯O hydrogen-bonded cyclic dimer with R(2) (2)(8) graph-set motif.

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

The benzimidazolone part of the title mol-ecule, C(17)H(25)N(3)O(3), is almost planar (r.m.s. deviation = 0.016 Å) and its mean plane is aligned at 7.9 (4) ° with respect to the mean plane of the nitro substituent. In the crystal, two mol-ecules are disposed about a center of inversion, generating a N-H⋯O hydrogen-bonded cyclic dimer with a R(2) (2)(8) graph-set motif.

1,3-Diallyl-5-chloro-1H-benzimidazol-2(3H)-one.

The benzimidazolone part of the title mol-ecule, C(13)H(13)ClN(2)O, is almost planar (r.m.s. deviation = 0.006 Å) and its mean plane is aligned at dihedral angles of 62.5 (1) and 78.0 (1)° with respect to the mean planes of the allyl substituents.

6-Bromo-1-[2-(2-oxo-1,3-oxazolidin-3-yl)eth-yl]-1H-imidazo[4,5-b]pyridin-2(3H)-one.

The title compound, C(11)H(11)BrN(4)O(3), features an ethane fragment substituted with an almost planar (r.m.s. deviation = 0.019 Å) imidazo[4,5-b]pyridone ring system and an envelope-shaped oxazolidine unit on separate C atoms. The N-CH(2)-CH(2)-N torsion angle is 52.5 (4)°. In the crystal, pairs of mol-ecules are linked by N-H⋯O hydrogen bonds into centrosymmetric dimers.

3-[(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl]-1,5-dimethyl-1,5-benzodiazepine-2,4-dione.

The title compound, C(21)H(21)N(5)O(2), is a 1,4-dimethyl-1,2,3-triazole having dimethyl-benzodiazepindione and phenyl substituents on each methyl group; the substituents are positioned on opposite sides of the five-membered ring. The seven-membered fused-ring of the larger substituent adopts a boat-shaped conformation (with the methine C atom as the prow).

3-[(1-Benzyl-1H-1,2,3-triazol-5-yl)methyl]-1,5-dimethyl-1,5-benzodiazepine-2,4-dione monohydrate.

In the title compound, C(21)H(21)N(5)O(2)·H(2)O, the seven-membered ring adopts a boat-shaped conformation with the methine C atom as the prow. In the crystal, the water mol-ecule links adjacent mol-ecules by O-H⋯O and O-H⋯N hydrogen bonds into a zigzag chain running along the c axis of the monoclinic cell.

1,3-Dibenzyl-6-bromo-1H-imidazo[4,5-b]pyridin-2(3H)-one.

The imidazopyridine fused-ring in the title compound, C(20)H(16)BrN(3)O, is planar (r.m.s. deviation = 0.011 Å). The phenyl rings of the benzyl substitutents twist away from the central five-membered ring in opposite directions; the rings are aligned at 61.3 (1) and 71.2 (1)° with respect to this ring.

4-Benzyl-6-bromo-2-(4-methoxy-phen-yl)-4H-imidazo[4,5-b]pyridine monohydrate.

The imidazopyridine fused ring in the title compound, C(20)H(16)BrN(3)O·H(2)O, is coplanar with the aromatic ring at the 2-position [dihedral angle = 5.2 (1)°]. In the five-membered imidazo portion, the C-N bond whose C atom is also connected to the pyridine N atom has predominantly double-bond character [1.334 (2) Å] whereas the C-N bond whose atom is connected to the pyridine C atom has predominantly single-bond character [1.371 (2) Å]. The water mol-ecule engages in hydrogen bonding with the latter N atom; it is also connected to a symmetry-related water mol-ecule, generating a linear chain structure.

3-Allyl-1,5-dibenzyl-1,5-benzodiazepine-2,4-dione.

The title compound, C(26)H(24)N(2)O(2), features a benzene ring fused with a seven-membered diazepine ring; the latter ring adopts a boat conformation (with the allyl-dimethyl-amino-methyl-bearing C atom as the prow and the fused-ring C atoms as the stern).

Ethyl 2-{4-[(1,5-dibenzyl-2,4-dioxo-2,3,4,5-tetra-hydro-1H-1,5-benzo-diazepin-3-yl)meth-yl]-1H-1,2,3-triazol-1-yl}acetate.

The reaction of 1,5-dibenzyl-3-propargyl-1,5-benzodiazepine-2,4-dione with ethyl azido-acetate in the presence of copper sulfate pentahydrate and sodium ascorbate leads to the formation of the title regioisomer, C(30)H(29)N(5)O(4), which features a phenyl-ene ring fused with a seven-membered diazepinyl ring. The latter ring adopts a boat conformation (with the methyl-triazolylacetate-bearing C atom as the prow and the fused-ring C atoms as the stern). The benzyl groups connected to the diazepinyl ring jprotrude from the sides; the methyl-triazolylacetate substituent occupies an axial position.