title: Relative substituent orientation in the structure of cis-3-chloro-1,3-dimethyl-N-(4-nitro-phen-yl)-2-oxo-cyclo-pentane-1-carboxamide.
abstract: The structure of the title compound, C14H15ClN2O4, prepared by reaction of a methacryloyl dimer with nitro-aniline, was determined to establish the relative substituent orientation on the cyclo-penta-none ring. In agreement with an earlier proposed reaction mechanism, the amide group and the methyl group adjacent to the chloro substituent adopt equatorial positions and relative cis orientation, whereas the Cl substituent itself and the methyl group adjacent to the amide have axial orientations relative to the mean plane of the five-membered ring. The conformation of the mol-ecule is stabilized by one classical N-H⋯O (2.18 Å) and one non-classical C-H⋯O (2.23 Å) hydrogen bond, each possessing an S(6) graph-set motif. The crystal packing is defined by several non-classical intra-molecular hydrogen bonds, as well as by partial stacking of the aromatic rings.
authors.affiliation: Department of Chemistry, Youngstown State University, 1 University Plaza, Youngstown, Ohio 44555, USA.
authors.forename: Matthias
authors.initials: M
authors.lastname: Zeller
authors.affiliation: University of Bremen, Department of Chemistry, Leobener Str. NW 2C, D-28359 Bremen, Germany.
authors.forename: Jonas
authors.initials: J
authors.lastname: Warneke
authors.affiliation: University of Bremen, Department of Chemistry, Leobener Str. NW 2C, D-28359 Bremen, Germany.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Azov
keywords: Diels–Alder reaction; crystal structure; hydrogen bonds; methacryloyl chloride dimer; π–π stacking