N-Paranitrophénylhydrazono-α-(2-méthyl-benzimidazol-1-yl)glyoxylate d'éthyle.

There are two independent mol-ecules in the asymmetric unit of the title compound {systematic name: ethyl 2-(2-methyl-1H-benzimidazol-1-yl)-2-[2-(4-nitro-phen-yl)hydrazinyl-idene]ethano-ate}, C(18)H(17)N(5)O(4). Each mol-ecule and its inversion-related partner are linked by a pair of inter-molecular N-H⋯N hydrogen bonds, forming inversion dimers in the crystal structure.

Ethyl 5,5-dichloro-3-(4-chloro-phen-yl)-3a-methyl-4a-phenyl-3a,4,4a,5-tetra-hydro-3H-aziridino[2,1-d][1,2,4]triazolo[4,3-a][1,5]benzodiazepine-1-carboxyl-ate.

In the title compound, C(27)H(23)Cl(3)N(4)O(2), the seven-membered diazepine ring adopts a boat conformation. The triazole ring makes dihedral angles of 17.24 (8) and 82.

Diethyl 1,4-bis-(4-nitro-phen-yl)-1,4-dihydro-1,2,4,5-tetra-zine-3,6-dicarboxyl-ate.

The complete mol-ecule of the title compound, C(20)H(18)N(6)O(8), is generated by a crystallographic twofold axis. The dihedral angle between the nitrobenzene rings is 43.5 (2)°.