Date Published: May 01, 2009
Publisher: International Union of Crystallography
Author(s): Shivanagere Nagojappa Narendra Babu, Aisyah Saad Abdul Rahim, Hasnah Osman, Samuel Robinson Jebas, Hoong-Kun Fun.
The asymmetric unit of the title compound, C11H14N2O4, comprises four crystallographically independent molecules (A, B, C and D) with similar geometries. In each molecule, the butylamino side chain is in an extended conformation, and the carboxyl and butylamino groups are almost coplanar with the attached benzene ring; the nitro group is slightly twisted away from the benzene ring. In the asymmetric unit, the benzene rings of molecules A, B and C are stacked parallel to one another, with a centroid–centroid distance of 3.6197 (11) or 3.6569 (11) Å, indicating π–π interactions. An intramolecular N—H⋯O hydrogen bond is observed in each independent molecule. In addition to the π–π interactions, the crystal packing is consolidated by intermolecular O—H⋯O and C—H⋯O hydrogen bonds and C—H⋯π interactions. The crystal studied was a non-merohedral twin. The minor twin component refined to a value of 0.290 (1).
For the synthesis of nitrobenzoic acid derivatives, see: Ishida et al. (2006 ▶); Mohd Maidin et al. (2008 ▶). For bond-length data, see: Allen et al. (1987 ▶). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶).