1-(3-Chloro-4-fluorophenyl)-5-(2-diazoacetyl)-4-phenylpyrrolidin-2-one

In the title compound, C18H13ClFN3O2, the pyrrolidine ring adopts an envelope conformation and the planar part is rotated by 4.3 (6)° from the plane of the benzene ring and is almost perperdicular both to the diazoacetyl unit [dihedral angle = 78.93 (7)°] and the phenyl ring [dihedral angle = 86.07 (7)°]. In the crystal, molecules are linked into a three-dimensional framework by C—H⋯O interactions. The molecular conformation is stabilized by an intramolecular C—H⋯O hydrogen bond.

In the title compound, C 18 H 13 ClFN 3 O 2 , the pyrrolidine ring adopts an envelope conformation and the planar part is rotated by 4.3 (6) from the plane of the benzene ring and is almost perperdicular both to the diazoacetyl unit [dihedral angle = 78.93 (7) ] and the phenyl ring [dihedral angle = 86.07 (7) ]. In the crystal, molecules are linked into a threedimensional framework by C-HÁ Á ÁO interactions. The molecular conformation is stabilized by an intramolecular C-HÁ Á ÁO hydrogen bond.

Experimental
The title compound was synthesized from the corresponding γ-lactam carboxylic acid which, in turn, was prepared following the general method (Ray et al. 1994(Ray et al. , 1998 developed in our laboratory, through the reaction of its acid chloride with diazomethane. Single crystal was grown by dissolving the compound in mixture (n-hexane-ethylacetate) solvent and then by slow evaporation technique at room temperature. It is a yellow colour solid; m.p. 407-409 K (n-hexane-ethylacetate).

Refinement
Hydrogen atoms were found in subsequent difference Fourier maps and included in observed positions and refined as free isotropic atoms.

Special details
Experimental. Data was collected using a X8 APEX II BRUKER-Nonius diffractometer equipped with an KYROFLEX low-temperature apparatus operating at 100 K. A suitable crystal was chosen and mounted on Mitegen MicroMount (radiation-hard polymer).
Data were measured using omega scans of 0.5° per frame for 10 s, such that a total of 1280 frames were collected in a optimized strategy and with a final resolution of 0.75 Å. Data integration and reduction was performed using the Apex2 (Bruker Nonius, 2005) suite software.
Absorption corrections were applied using SADABS (2004)  Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness 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 threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) 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.
All non-hydrogen atoms were refined anisotropically. Hydrogen were found in subsequent difference Fourier maps and included in observed positions and refined as free isotropic atoms.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq