2-Chloro-N-(4-fluoro­phen­yl)acetamide

In the title compound, C₈H₇ClFNO, an intra­molecular C—H...O hydrogen bond forms a six-membered ring. In the crystal structure, mol­ecules are linked by inter­molecular N—H...O hydrogen bonds, forming infinite chains along the c axis.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.009 Å
• R factor = 0.047
• wR factor = 0.126
• Data-to-parameter ratio = 8.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT230_ALERT_2_C Hirshfeld Test Diff for    N      --  C7      ..       5.08 su
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C5     --  C6      ..       5.11 su
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C1
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          9
PLAT431_ALERT_2_C Short Inter HL..A Contact  Cl     ..  F       ..       3.13 Ang.
PLAT180_ALERT_4_C Check Cell Rounding: # of Values Ending with 0 =          3

Alert level G
REFLT03_ALERT_4_G  WARNING: Large fraction of Friedel related reflns may
                     be needed to determine absolute structure
           From the CIF: _diffrn_reflns_theta_max           25.20
           From the CIF: _reflns_number_total                861
           Count of symmetry unique reflns          769
           Completeness (_total/calc)            111.96%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured        92
           Fraction of Friedel pairs measured     0.120
           Are heavy atom types Z>Si present        yes
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

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

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 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
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

N-(substituted phenyl)-2-chloroacetamides are important intermediates in organic synthesis. They can be used in the synthesis of many derivatives such as (quinolin-8-yloxy) acetamide (Zhang et al., 2006) and 2,5-piperazinedione (Wen et al., 2006). In our studies in this area, the title compound,(I), was synthesized and structurally characterised.

The bond lengths and angles in (I) are within normal ranges (Allen et al., 1987). An intramolecular C—H···O interaction occurs (Fig. 1) and an intermolecular N—H···O hydrogen bond helps to establish the packing (Table 1).

Related literature

For related compounds, see: Wen et al. (2006); Zhang et al. (2006). For reference structural data, see: Allen et al. (1987).

S2. Experimental

Chloroacetyl chloride (0.05 mol) was added to a solution of 4-nitrophenylamine (0.05 mol) and triethylamine (0.05 mol) in toluene (50 ml) over a period of 30 min, with cooling in an ice bath, and then the mixture was stirred at room remperature for 4 h. After separation of the triethylamine hydrochloride by filtration, the organic phase was washed three times with water. The toluene layer was removed and evaporated. Pink blocks of (I) were obtained by slow evaporation of a chloroform solution over a period of 7 d.

S3. Refinement

The H atoms were positioned geometrically (N—H = 0.86 Å, C—H = 0.93-0.97Å) and refined as riding with U_iso(H) = xU_eq(carrier).

Computing details

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

Fig. 1. The molecular structure of (I) with displacement ellipsoids for the non-hydrogen atoms drawn at the 50% probability level. The intramolecular hydrogen bond is shown as a dashed line.

2-Chloro-N-(4-fluorophenyl)acetamide

Crystal data

C8H7ClFNO	F(000) = 384
Mr = 187.60	Dx = 1.479 Mg m^−3
Monoclinic, Cc	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C -2yc	Cell parameters from 25 reflections
a = 4.7410 (9) Å	θ = 8–12°
b = 20.062 (4) Å	µ = 0.42 mm^−1
c = 8.9860 (18) Å	T = 293 K
β = 99.60 (3)°	Block, pink
V = 842.7 (3) Å^3	0.30 × 0.20 × 0.05 mm
Z = 4

Data collection

Enraf–Nonius CAD-4 diffractometer	610 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.016
Graphite monochromator	θmax = 25.2°, θmin = 2.0°
ω/2θ scans	h = 0→5
Absorption correction: ψ scan (North et al., 1968)	k = 0→24
Tmin = 0.885, Tmax = 0.980	l = −10→10
974 measured reflections	3 standard reflections every 200 reflections
861 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.046	H-atom parameters constrained
wR(F^2) = 0.126	w = 1/[σ^2(Fo^2) + (0.P)^2 + 0.5P] where P = (Fo^2 + 2Fc^2)/3
S = 1.00	(Δ/σ)max < 0.001
861 reflections	Δρmax = 0.16 e Å^−3
103 parameters	Δρmin = −0.20 e Å^−3
0 restraints	Absolute structure: Flack (1983), 92 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.18 (17)

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
Cl	−0.4033 (4)	0.15199 (10)	0.5685 (2)	0.1096 (7)
N	0.1497 (11)	0.2970 (2)	0.6731 (5)	0.0738 (14)
H1	0.2033	0.2848	0.7653	0.089*
O	−0.1268 (10)	0.2652 (2)	0.4535 (5)	0.084
F	0.6949 (14)	0.5279 (2)	0.5602 (6)	0.147 (2)
C1	0.5590 (19)	0.4687 (3)	0.5826 (8)	0.095 (2)
C2	0.3302 (19)	0.4493 (4)	0.4775 (8)	0.097 (2)
H2A	0.2684	0.4749	0.3920	0.116*
C3	0.1935 (15)	0.3901 (3)	0.5030 (6)	0.0817 (18)
H3A	0.0450	0.3743	0.4308	0.098*
C4	0.2759 (13)	0.3546 (3)	0.6344 (6)	0.0707 (15)
C5	0.5091 (15)	0.3787 (3)	0.7356 (7)	0.0798 (17)
H5A	0.5715	0.3539	0.8224	0.096*
C6	0.6503 (19)	0.4357 (4)	0.7157 (8)	0.099 (2)
H6A	0.7995	0.4516	0.7874	0.119*
C7	−0.0366 (13)	0.2576 (3)	0.5950 (5)	0.0710 (16)
C8	−0.1284 (15)	0.1998 (3)	0.6748 (6)	0.089 (2)
H8A	−0.1937	0.2153	0.7654	0.107*
H8B	0.0358	0.1712	0.7058	0.107*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl	0.1293 (15)	0.1275 (15)	0.0742 (9)	−0.0277 (13)	0.0237 (9)	−0.0087 (10)
N	0.089 (3)	0.082 (3)	0.051 (2)	0.010 (3)	0.013 (2)	0.004 (2)
O	0.084	0.084	0.084	0.000	0.014	0.000
F	0.213 (7)	0.120 (3)	0.121 (3)	−0.062 (4)	0.067 (4)	0.001 (3)
C1	0.117 (6)	0.091 (5)	0.086 (5)	−0.031 (5)	0.043 (5)	0.001 (4)
C2	0.121 (6)	0.103 (5)	0.074 (4)	0.000 (5)	0.039 (4)	0.017 (4)
C3	0.090 (4)	0.096 (5)	0.063 (3)	−0.006 (4)	0.025 (3)	0.002 (3)
C4	0.078 (4)	0.080 (4)	0.058 (3)	0.008 (3)	0.020 (3)	0.008 (3)
C5	0.095 (4)	0.083 (4)	0.067 (3)	−0.016 (4)	0.029 (3)	0.000 (3)
C6	0.115 (6)	0.116 (5)	0.074 (4)	−0.007 (5)	0.038 (4)	0.010 (4)
C7	0.072 (3)	0.102 (4)	0.039 (2)	−0.003 (3)	0.009 (2)	−0.011 (3)
C8	0.111 (5)	0.110 (5)	0.044 (3)	−0.017 (4)	0.005 (3)	0.013 (3)

Geometric parameters (Å, º)

Cl—C8	1.765 (7)	C3—C4	1.379 (8)
N—C7	1.300 (7)	C3—H3A	0.9300
N—C4	1.373 (8)	C4—C5	1.396 (9)
N—H1	0.8600	C5—C6	1.353 (10)
O—C7	1.281 (6)	C5—H5A	0.9300
F—C1	1.381 (7)	C6—H6A	0.9300
C1—C2	1.371 (10)	C7—C8	1.467 (8)
C1—C6	1.372 (10)	C8—H8A	0.9700
C2—C3	1.390 (9)	C8—H8B	0.9700
C2—H2A	0.9300
C7—N—C4	131.3 (5)	C6—C5—C4	124.2 (6)
C7—N—H1	114.3	C6—C5—H5A	117.9
C4—N—H1	114.3	C4—C5—H5A	117.9
C2—C1—C6	124.2 (7)	C5—C6—C1	115.6 (7)
C2—C1—F	118.6 (7)	C5—C6—H6A	122.2
C6—C1—F	117.0 (7)	C1—C6—H6A	122.2
C1—C2—C3	117.7 (6)	O—C7—N	123.2 (6)
C1—C2—H2A	121.1	O—C7—C8	120.1 (5)
C3—C2—H2A	121.1	N—C7—C8	116.5 (4)
C4—C3—C2	120.7 (6)	C7—C8—Cl	114.7 (4)
C4—C3—H3A	119.7	C7—C8—H8A	108.6
C2—C3—H3A	119.7	Cl—C8—H8A	108.6
N—C4—C3	125.4 (6)	C7—C8—H8B	108.6
N—C4—C5	117.3 (5)	Cl—C8—H8B	108.6
C3—C4—C5	117.3 (6)	H8A—C8—H8B	107.6
C6—C1—C2—C3	−4.3 (12)	C3—C4—C5—C6	2.8 (10)
F—C1—C2—C3	−179.1 (7)	C4—C5—C6—C1	−3.0 (11)
C1—C2—C3—C4	3.9 (11)	C2—C1—C6—C5	3.8 (12)
C7—N—C4—C3	11.2 (11)	F—C1—C6—C5	178.7 (7)
C7—N—C4—C5	−168.0 (7)	C4—N—C7—O	4.7 (11)
C2—C3—C4—N	177.7 (6)	C4—N—C7—C8	−179.3 (6)
C2—C3—C4—C5	−3.1 (10)	O—C7—C8—Cl	−9.0 (9)
N—C4—C5—C6	−177.9 (7)	N—C7—C8—Cl	174.8 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···O	0.93	2.36	2.925 (8)	119
N—H1···O^i	0.86	2.02	2.853 (6)	164

Symmetry code: (i) x+1/2, −y+1/2, z+1/2.