N-Cyclohexyl-2-fluorobenzamide

In the title compound, C13H16FNO, the fluorobenzene ring plane and the plane through the amide unit are inclined at a dihedral angle of 29.92 (7)°. The cyclohexane ring adopts a chair conformation. In the crystal structure, N—H⋯O hydrogen bonds, augmented by weak C—H⋯O interactions, link the molecules into transverse chains along a. These chains are linked into zigzag columns down a by C—H⋯F hydrogen bonds and C—H⋯π interactions.

In the title compound, C 13 H 16 FNO, the fluorobenzene ring plane and the plane through the amide unit are inclined at a dihedral angle of 29.92 (7) . The cyclohexane ring adopts a chair conformation. In the crystal structure, N-HÁ Á ÁO hydrogen bonds, augmented by weak C-HÁ Á ÁO interactions, link the molecules into transverse chains along a. These chains are linked into zigzag columns down a by C-HÁ Á ÁF hydrogen bonds and C-HÁ Á Á interactions.
NA is grateful to the Higher Education Commission of Pakistan for financial support for a PhD programme. We also thank the University of Otago for the purchase of the diffractometer.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: LH2713).

Comment
The background to this study has been described in our earlier paper reporting the structure of 4-chloro-N-(3-methoxyphenyl)-benzamide (Saeed et al. 2008).
In the crystal structure, chains are formed that run in opposite directions along a through N-H···O hydrogen bonds, Table   1 Experimental 2-Fluorobenzoyl chloride (1 mmol) in CHCl 3 was treated with cyclohexyl amine (3.5 mmol) under a nitrogen atmosphere at reflux for 5 h. Upon cooling, the reaction mixture was diluted with CHCl 3 and washed consecutively with 1 M aq HCl and saturated aq NaHCO 3 . The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. Crystallization of the residue from CHCl 3 afforded the title compound (79%) as white needles: Anal. calcd. for C 13 H 16 FNO: C 70.56, H 7.29, N 6.33%; found: C 70.08, H 7.31, N 6.38%.

Refinement
The H atom bound to N1 was located in a difference electron density map and refined freely with an isotropic displacememt parameter. All other H-atoms were refined using a riding model with d(C-H) = 0.95 Å, U iso = 1.2U eq (C) for aromatic and 0.98 Å, U iso = 1.5U eq (C) for CH 3 H atoms. In the absence of significant anomalous dispersion effects, Friedel pairs were averaged.
supplementary materials sup-2 Figures   Fig. 1. The structure of (I) with displacement ellipsoids for the non-hydrogen atoms drawn at the 50% probability level.

Special details
Geometry. All e.s. 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.