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.

Key indicators

• Single-crystal X-ray study
• T = 91 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.036
• wR factor = 0.114
• Data-to-parameter ratio = 14.3

checkCIF/PLATON results

No syntax errors found



Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.822     0.993
            Tmin(prime) and Tmax expected:      0.964     0.993
            RR(prime) =      0.852
            Please check that your absorption correction is appropriate.
            Value of measurement temperature given =    91.000
            Value of melting point given =     0.000
PLAT061_ALERT_4_C Tmax/Tmin Range Test RR' too Large .............       0.85
PLAT480_ALERT_4_C Long H...A H-Bond Reported H9B    ..  O1      ..       2.67 Ang.

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           33.36
           From the CIF: _reflns_number_total               2117
           Count of symmetry unique reflns         2327
           Completeness (_total/calc)             90.98%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no
PLAT720_ALERT_4_G Number of Unusual/Non-Standard Labels ..........          1

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   4 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. 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).

We report here the structure of the title 2-fluorobenzamide derivative, I, Fig 1. The C2—C1—O1—N1—C8 unit is planar with a maximum deviation of 0.0223 (10) Å. This plane makes a dihedral angle of 29.92 (7) ° with the fluorobenzene ring plane. The N-cyclohexyl ring adopts a chair conformation with Cremer-Pople puckering parameters Q(2)= 0.0138 (15) Å, ϕ(2) = 23 (2)° and Q(3) = 0.5763 (15)Å (Cremer & Pople, 1975). 2-fluorobenzamide derivatives with aliphatic substituents on the amide N atom are unusual with only one reasonably comparable derivative (Kobal et al. 1990) of the Cambridge Structural Database V5.29 (Allen, 2002). In contrast, N-aryl derivatives are more common and the salient bond distances and angles in the present molecule agree well with those reported previously (see for example Chopra & Guru Row, 2008; Donnelly et al., 2008; Hou et al., 2004).

In the crystal structure, chains are formed that run in opposite directions along a through N—H···O hydrogen bonds, Table 1, Fig 2. These interactions are supported by weak C9—H9B···O1 hydrogen bonds. Additional weak C—H···F hydrogen bonds and C—H···π interactions link these chains into zigzag columns down a Fig. 3.

Related literature

For background see: Saeed et al. (2008). For related structures, see: Kobal et al. (1990); Chopra & Guru Row (2008); Donnelly et al. (2008); Hou et al. (2004); Saeed et al. (2008). For information on the Cambridge Structural Database, see: Allen (2002). For ring puckering parameters, see: Cremer & Pople (1975).

S2. Experimental

2-Fluorobenzoyl chloride (1 mmol) in CHCl₃ 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 CHCl₃ and washed consecutively with 1 M aq HCl and saturated aq NaHCO₃. The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. Crystallization of the residue from CHCl₃ afforded the title compound (79%) as white needles: Anal. calcd. for C₁₃H₁₆FNO: C 70.56, H 7.29, N 6.33%; found: C 70.08, H 7.31, N 6.38%.

S3. 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 CH₃ H atoms. In the absence of significant anomalous dispersion effects, Friedel pairs were averaged.

Computing details

Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 (Bruker, 2006) and SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008) and TITAN (Hunter & Simpson, 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and TITAN (Hunter & Simpson, 1999); molecular graphics: ORTEPIII (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), enCIFer (Allen et al., 2004), PLATON (Spek, 2003) and publCIF (Westrip, 2008).

Figures

	Fig. 1. The structure of (I) with displacement ellipsoids for the non-hydrogen atoms drawn at the 50% probability level.
	Fig. 2. Transverse chains formed along a by N—H···O hydrogen bonds.
	Fig. 3. Crystal packing of (I) viewed down the a axis.

N-Cyclohexyl-2-fluorobenzamide

Crystal data

C13H16FNO	F(000) = 236
Mr = 221.27	Dx = 1.305 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 2700 reflections
a = 5.1804 (6) Å	θ = 3.4–32.5°
b = 6.5309 (8) Å	µ = 0.09 mm^−1
c = 16.6522 (19) Å	T = 91 K
β = 91.336 (6)°	Needle, colourless
V = 563.24 (11) Å^3	0.39 × 0.16 × 0.08 mm
Z = 2

Data collection

Bruker APEXII CCD area-detector diffractometer	2117 independent reflections
Radiation source: fine-focus sealed tube	1884 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.031
ω scans	θmax = 33.4°, θmin = 1.2°
Absorption correction: multi-scan (SADABS; Bruker, 2006)	h = −7→7
Tmin = 0.822, Tmax = 0.993	k = −8→9
7905 measured reflections	l = −25→24

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.114	H atoms treated by a mixture of independent and constrained refinement
S = 1.12	w = 1/[σ^2(Fo^2) + (0.0702P)^2 + 0.0113P] where P = (Fo^2 + 2Fc^2)/3
2117 reflections	(Δ/σ)max = 0.002
148 parameters	Δρmax = 0.30 e Å^−3
1 restraint	Δρmin = −0.26 e Å^−3

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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	1.2369 (2)	0.9202 (2)	0.24742 (7)	0.0187 (3)
C1	1.0126 (3)	0.9513 (2)	0.22274 (9)	0.0122 (3)
C2	0.9598 (3)	1.1225 (2)	0.16419 (9)	0.0124 (3)
C3	0.7571 (3)	1.1292 (2)	0.10763 (9)	0.0142 (3)
F1	0.5940 (2)	0.96735 (18)	0.10014 (5)	0.0207 (2)
C4	0.7162 (3)	1.2929 (3)	0.05603 (9)	0.0187 (3)
H4	0.5765	1.2913	0.0180	0.022*
C5	0.8825 (3)	1.4593 (3)	0.06068 (10)	0.0207 (3)
H5	0.8553	1.5740	0.0264	0.025*
C6	1.0902 (3)	1.4580 (3)	0.11584 (10)	0.0203 (3)
H6	1.2055	1.5711	0.1188	0.024*
C7	1.1270 (3)	1.2908 (3)	0.16621 (9)	0.0162 (3)
H7	1.2697	1.2906	0.2031	0.019*
N1	0.8095 (3)	0.8430 (2)	0.24730 (8)	0.0129 (3)
HN1	0.655 (4)	0.883 (4)	0.2321 (12)	0.015*
C8	0.8378 (3)	0.6807 (2)	0.30746 (9)	0.0120 (3)
H8	1.0140	0.6199	0.3028	0.014*
C9	0.6393 (3)	0.5126 (2)	0.29046 (10)	0.0144 (3)
H9A	0.6632	0.4574	0.2358	0.017*
H9B	0.4631	0.5708	0.2927	0.017*
C10	0.6683 (3)	0.3397 (3)	0.35200 (10)	0.0181 (3)
H10A	0.8385	0.2730	0.3462	0.022*
H10B	0.5329	0.2354	0.3416	0.022*
C11	0.6456 (3)	0.4213 (3)	0.43778 (10)	0.0193 (3)
H11A	0.4685	0.4736	0.4455	0.023*
H11B	0.6765	0.3084	0.4765	0.023*
C12	0.8402 (3)	0.5932 (3)	0.45444 (10)	0.0184 (3)
H12A	0.8131	0.6494	0.5088	0.022*
H12B	1.0175	0.5368	0.4532	0.022*
C13	0.8128 (3)	0.7651 (3)	0.39258 (9)	0.0167 (3)
H13A	0.9481	0.8695	0.4029	0.020*
H13B	0.6425	0.8319	0.3977	0.020*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0108 (5)	0.0210 (6)	0.0242 (6)	−0.0001 (4)	−0.0012 (4)	0.0060 (5)
C1	0.0126 (6)	0.0105 (6)	0.0135 (6)	0.0003 (5)	0.0004 (5)	0.0002 (5)
C2	0.0123 (6)	0.0121 (6)	0.0127 (6)	0.0005 (5)	0.0017 (5)	0.0002 (5)
C3	0.0137 (6)	0.0154 (7)	0.0134 (6)	−0.0003 (6)	0.0008 (5)	0.0008 (6)
F1	0.0216 (5)	0.0223 (5)	0.0178 (4)	−0.0069 (4)	−0.0065 (4)	0.0005 (4)
C4	0.0184 (7)	0.0235 (8)	0.0143 (6)	0.0043 (7)	0.0022 (5)	0.0036 (6)
C5	0.0218 (7)	0.0200 (8)	0.0207 (7)	0.0060 (6)	0.0061 (6)	0.0080 (7)
C6	0.0204 (7)	0.0151 (7)	0.0256 (8)	−0.0007 (6)	0.0061 (6)	0.0043 (7)
C7	0.0151 (7)	0.0149 (7)	0.0186 (7)	−0.0016 (6)	0.0012 (5)	0.0012 (6)
N1	0.0103 (5)	0.0135 (6)	0.0149 (6)	−0.0007 (5)	−0.0013 (4)	0.0032 (5)
C8	0.0114 (6)	0.0108 (6)	0.0136 (6)	0.0003 (5)	−0.0010 (5)	0.0021 (5)
C9	0.0133 (6)	0.0115 (7)	0.0183 (7)	−0.0011 (5)	−0.0006 (5)	−0.0004 (5)
C10	0.0191 (7)	0.0121 (7)	0.0230 (8)	−0.0011 (6)	−0.0002 (6)	0.0026 (6)
C11	0.0188 (7)	0.0177 (8)	0.0215 (7)	0.0016 (6)	0.0029 (6)	0.0071 (6)
C12	0.0224 (7)	0.0175 (8)	0.0152 (7)	0.0007 (6)	−0.0011 (6)	0.0028 (6)
C13	0.0234 (7)	0.0122 (7)	0.0142 (6)	−0.0008 (6)	−0.0023 (6)	0.0004 (5)

Geometric parameters (Å, º)

O1—C1	1.2402 (18)	C8—C13	1.529 (2)
C1—N1	1.3395 (19)	C8—H8	1.0000
C1—C2	1.504 (2)	C9—C10	1.530 (2)
C2—C3	1.395 (2)	C9—H9A	0.9900
C2—C7	1.399 (2)	C9—H9B	0.9900
C3—F1	1.3571 (19)	C10—C11	1.532 (2)
C3—C4	1.384 (2)	C10—H10A	0.9900
C4—C5	1.388 (3)	C10—H10B	0.9900
C4—H4	0.9500	C11—C12	1.530 (2)
C5—C6	1.398 (2)	C11—H11A	0.9900
C5—H5	0.9500	C11—H11B	0.9900
C6—C7	1.387 (2)	C12—C13	1.528 (2)
C6—H6	0.9500	C12—H12A	0.9900
C7—H7	0.9500	C12—H12B	0.9900
N1—C8	1.4632 (19)	C13—H13A	0.9900
N1—HN1	0.87 (2)	C13—H13B	0.9900
C8—C9	1.526 (2)
O1—C1—N1	123.26 (14)	C8—C9—C10	110.57 (12)
O1—C1—C2	119.42 (13)	C8—C9—H9A	109.5
N1—C1—C2	117.29 (12)	C10—C9—H9A	109.5
C3—C2—C7	116.58 (14)	C8—C9—H9B	109.5
C3—C2—C1	125.69 (14)	C10—C9—H9B	109.5
C7—C2—C1	117.74 (13)	H9A—C9—H9B	108.1
F1—C3—C4	117.29 (13)	C9—C10—C11	111.03 (14)
F1—C3—C2	119.65 (14)	C9—C10—H10A	109.4
C4—C3—C2	123.03 (15)	C11—C10—H10A	109.4
C3—C4—C5	118.96 (14)	C9—C10—H10B	109.4
C3—C4—H4	120.5	C11—C10—H10B	109.4
C5—C4—H4	120.5	H10A—C10—H10B	108.0
C4—C5—C6	119.94 (15)	C12—C11—C10	111.09 (14)
C4—C5—H5	120.0	C12—C11—H11A	109.4
C6—C5—H5	120.0	C10—C11—H11A	109.4
C7—C6—C5	119.64 (16)	C12—C11—H11B	109.4
C7—C6—H6	120.2	C10—C11—H11B	109.4
C5—C6—H6	120.2	H11A—C11—H11B	108.0
C6—C7—C2	121.84 (14)	C13—C12—C11	111.48 (13)
C6—C7—H7	119.1	C13—C12—H12A	109.3
C2—C7—H7	119.1	C11—C12—H12A	109.3
C1—N1—C8	121.65 (12)	C13—C12—H12B	109.3
C1—N1—HN1	118.4 (16)	C11—C12—H12B	109.3
C8—N1—HN1	119.3 (15)	H12A—C12—H12B	108.0
N1—C8—C9	109.73 (12)	C12—C13—C8	110.57 (13)
N1—C8—C13	111.36 (12)	C12—C13—H13A	109.5
C9—C8—C13	111.09 (13)	C8—C13—H13A	109.5
N1—C8—H8	108.2	C12—C13—H13B	109.5
C9—C8—H8	108.2	C8—C13—H13B	109.5
C13—C8—H8	108.2	H13A—C13—H13B	108.1
O1—C1—C2—C3	152.45 (16)	C1—C2—C7—C6	−178.45 (14)
N1—C1—C2—C3	−29.4 (2)	O1—C1—N1—C8	1.5 (2)
O1—C1—C2—C7	−27.8 (2)	C2—C1—N1—C8	−176.60 (13)
N1—C1—C2—C7	150.43 (14)	C1—N1—C8—C9	−147.62 (14)
C7—C2—C3—F1	177.27 (13)	C1—N1—C8—C13	88.97 (17)
C1—C2—C3—F1	−2.9 (2)	N1—C8—C9—C10	179.13 (12)
C7—C2—C3—C4	−0.8 (2)	C13—C8—C9—C10	−57.29 (16)
C1—C2—C3—C4	179.00 (14)	C8—C9—C10—C11	56.43 (17)
F1—C3—C4—C5	−178.59 (14)	C9—C10—C11—C12	−55.36 (18)
C2—C3—C4—C5	−0.5 (2)	C10—C11—C12—C13	55.12 (19)
C3—C4—C5—C6	1.2 (2)	C11—C12—C13—C8	−55.66 (18)
C4—C5—C6—C7	−0.7 (3)	N1—C8—C13—C12	179.44 (13)
C5—C6—C7—C2	−0.7 (2)	C9—C8—C13—C12	56.80 (17)
C3—C2—C7—C6	1.4 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—HN1···O1^i	0.87 (2)	2.20 (2)	3.0092 (18)	153.8 (19)
C9—H9B···O1^i	0.99	2.67	3.446 (2)	136
C4—H4···F1^ii	0.95	2.43	3.2326 (19)	142
C5—H5···Cg1^iii	0.95	2.96	3.759 (2)	142
C9—H9A···Cg1^iv	0.99	2.71	3.644 (2)	157

Symmetry codes: (i) x−1, y, z; (ii) −x+1, y+1/2, −z; (iii) −x+2, y+1/2, −z; (iv) x, y−1, z.