Crystal structure of 3-(4-chlorophenoxy)-4-(2-nitrophenyl)azetidin-2-one with an unknown solvate

In the title compound, C15H11ClN2O4, the central β-lactam ring is approximately planar [maximum deviation = 0.044 (2) Å for the N atom from the mean plane] and subtends dihedral angles of 61.17 (11) and 40.21 (12) °, respectively, with the nitro and chlorobenzene rings. Both substituents lie to the same side of the β-lactam core. In the crystal, N—H⋯O hydrogen bonds link the molecules into C(4) chains propagating in [010]. The chains are cross-linked by C—H⋯O and weak C—H⋯π interactions, generating a three-dimensional network. The solvent molecules were found to be highly disordered and their contribution to the scattering was removed with the SQUEEZE procedure in PLATON [Spek (2009 ▸). Acta Cryst. D65, 148–155], which indicated a solvent cavity of volume 318 Å3 containing approximately 114 electrons. These solvent molecules are not considered in the given chemical formula and other crystal data.

In the title compound ( Fig. 1), the β-lactam ring is nearly planar with a maximum deviation of 0.044 (2) Å for N1 from the mean plane. The carboxyl O atom O1 attached to the β-lactam ring deviates by -0.137 (1) Å from the mean plane of the ring. The β-lactam ring makes dihedral angles of 61.17 (11) and 40.21 (12) ° with the nitro and choloro-benzene rings, respectively.
All bond lengths and angles are comparable with those reported in a related structure (Butcher et al., 2011).

S3. Refinement
C and N-bound H atoms were positioned geometrically (C-H = 0.93 -0.98 Å and N-H =0.86 Å), and refined using a riding model with U iso (H) = 1.2U eq (C,N). The twenty two reflections were omitted owing to bad disagreement. The crystal sup-2 Acta Cryst. (2015). E71, o8-o9 quality and data was not good enough. A region of disordered electron density, most probably disordered solvent molecules, occupying voids of ca 318 Å 3 for an electron count of 114, was removed with the SQUEEZE procedure in PLATON [Spek (2009). Acta Cryst. D65, 148-155] following unsuccessful attempts to model it as a plausible solvent molecule. Their formula mass and unit-cell characteristics were not taken into account during refinement.

Figure 1
View of the title compound with displacement ellipsoids for non-H atoms drawn at the 30% probability level.

Figure 2
View of the hydrogen bonding of the title compound along b axis. Only H atoms involved in H bonding are shown. Special details Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles Refinement. Refinement on F 2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The observed criterion of F 2 > σ(F 2 ) is used only for calculating -R-factor-obs etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.