1-(4-Bromobenzoyl)-2-phenylpyrrolidine-2-carboxamide

In the title compound, C18H17BrN2O2, which is a potential human immunodeficiency virus type 1 (HIV-1) non-nucleoside reverse transcriptase inhibitor, the pyrrolidine ring exhibits an envelope conformation. In the crystal structure, intermolecular N—H⋯O hydrogen bonds [N⋯O = 2.861 (3) Å] link the molecules into centrosymmetric dimers.


Comment
The title compound, (I), belongs to a family of non-nucleoside reverse transcriptase inhibitors (NNRTIs), which exhibit potential HIV-1 RT inhibition properties (De Clercq, 1996).
In (I) (Fig. 1), all bond lengths and angles are in good agreement with those observed in the related compounds (Karapetyan et al., 2002;Tamazyan et al., 2002Tamazyan et al., , 2007. Both H atoms of amide group, H7b and H7a, respectively, are involved in intra-and intermolecular N-H···O hydrogen bonds ( Table 1). The latter one links the molecules into centrosymmetric dimers (Fig. 2).

Refinement
All H atoms were located on a difference map. Atoms H7a and H7b were refined isotropically. C-bound H atoms were placed in idealized positions (C-H 0.93-0.97 Å) and refined as riding, with U iso = 1.2 U eq (C). Fig. 1. The molecular structure of (I) showing the atomic numbering and displacement ellipsoids at the 50% probability level. H atoms omitted for clarity.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.
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 > 2sigma(F 2 ) is used only for calculating R-factors(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.