Crystal structure of (Z)-ethyl 3-[2-(5-methyl-7-nitro-1H-indole-2-carbonyl)hydrazinylidene]butanoate

The reaction of 5-methyl-7-nitro-1H-indole-2-carbohydrazide with ethyl acetoacetate yielded the title molecule, C16H18N4O5, in which the indole ring is almost planar, with the greatest deviation from the mean plane being 0.006 (2) Å. The nine atoms of the indole ring are almost perpendicular to the mean plane through the ethyl acetate group, as indicated by the dihedral angle of 87.02 (4)° between them. In the crystal, centrosymmetric supramolecular dimers are formed via N—H...O hydrogen bonds and eight-membered amide {...HNCO}2 synthons. These are consolidated into a three-dimensional architecture by C—H...O contacts, and by π–π interactions between six-membered rings [inter-centroid distance = 3.499 (2) Å]