(E)-2-(2-Fluoro­benzyl­idene)butanoic acid

Abstract

In the crystal structure of the title compound, C₁₁H₁₁FO₂, the methine CH forms an intra­molecular hydrogen bond with the carboxyl­ O atom. The mol­ecules form dimers through hydrogen bonding between carboxyl­ groups. These dimers are linked to each other by C—H⋯O contacts between the benzene and carbonyl groups of adjoining mol­ecules. In addition, there are weak inter­molecular C—H⋯F contacts.

Related literature

For related literature, see: Burns & Hagaman (1993 ▶); Burt (2004 ▶); Forgó et al. (2005 ▶); Hertog et al. (1995 ▶); Muhammad et al. (2007 ▶). For details of the Cambridge Structural Database, see: Allen (2002 ▶).

Experimental

Crystal data

• C₁₁H₁₁FO₂

• M _r = 194.20

• Monoclinic,

• a = 4.1895 (4) Å

• b = 17.4362 (19) Å

• c = 13.8134 (15) Å

• β = 96.719 (3)°

• V = 1002.12 (18) ų

• Z = 4

• Mo Kα radiation radiation

• μ = 0.10 mm⁻¹

• T = 296 (2) K

• 0.25 × 0.18 × 0.12 mm

Data collection

• Bruker Kappa APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.935, T _max = 0.958

• 8632 measured reflections

• 2981 independent reflections

• 1704 reflections with I > 2σ(I)

• R _int = 0.026

Refinement

• R[F ² > 2σ(F ²)] = 0.050

• wR(F ²) = 0.164

• S = 1.04

• 2981 reflections

• 131 parameters

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.41 e Å⁻³

• Δρ_min = −0.21 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2007 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶) and PLATON (Spek, 2003 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O2i	0.97 (2)	1.66 (2)	2.6325 (18)	177.7 (12)
C3—H3⋯O1	0.93	2.32	2.713 (2)	105
C6—H6⋯O2ii	0.93	2.53	3.421 (2)	160
C8—H8⋯F1iii	0.93	2.55	3.266 (2)	134 (1)

Symmetry codes: (i) ; (ii) ; (iii) .

supplementary crystallographic information

Comment

Cinnamic acid derivatives are well known for their antibacterial, antifungal antiparasitic (Burt, 2004), and antitumor activity (Hertog et al., 1995). They are also used in the shikmic acid metabolic pathways of higher plants (Forgó et al., 2005).

In the structure of the title compound (I), there are two C-atoms between the carboxylate and 2-fluorophenyl C-atoms. A search of CCDC (Allen, 2002) shows that a structure of 2-amino-2-(2-fluorophenyl)acetic acid (Burns et al., 1993) has been published in which there is only a single C-atom between carboxylate and phenyl ring. Moreover, there is no structure of this kind with a different position for the F-atom.

The C1=O2 bond distance [1.2301 (18) Å], is significantly shorter than the C1—O1 distance [1.3006 (18) Å]. The C1—O1 bond lengthened due to the formation of intramolecular and intermolecular H-bonds. The value of C2=C3 is 1.334 (2) Å. The phenyl ring bond distances are in the normal range but the C4—C5—C6 bond angle is 124.27 (18)°, due to the influence of the F substituent attached to C5. The dihedral angle between the planes formed by (O1, C1, and O2) and (C2, C10, and C11) is 80.97 (18)°, and the dihedral angles between these planes and the phenyl ring are 52.88 (10)° and 67.17 (15)° respectively. The molecules are stabilized by intramolecular and intermolecular H-bonds. The title compound forms dimers through H-bonding, O1—H1···O2ⁱ [symmetry code i = -x + 2, -y, -z] as shown in Fig 2. These dimers are linked to each other through a C6—H6···O2ⁱⁱ interaction [symmetry code ii = -x + 1, y + 1/2, -z + 1/2]. Details of the H-bonding are given in Table 1. In addition there is a weak C8—H8···F1ⁱⁱⁱ intermolecular interaction [symmetry code iii = x, 1/2 - y, 1/2 + z] with a distance 3.2658 (25) Å between C8 and F1ⁱⁱⁱ.

Experimental

Compound (I) was synthesized as reported earlier (Niaz, et al., 2007). A mixture of 2-fluorobenzaldehyde (1.05 ml, 10 mmol), ethylmalonic acid (2.64 g, 20 mmol) and piperidine (1.98 ml, 20 mmol) in a pyridine (12.5 ml) solution was heated on a steam-bath for 24 h. The reaction mixture was cooled and added to a mixture of 25 ml of concentrated HCl and 50 g of ice. The precipitate formed in the acidified mixture was filtered off and washed with ice-cold water. The product was recrystallized from ethanol. The yield was 65%, m.p. 94 °C.

Figures

Fig. 1.

ORTEP drawing of the title compound, C11H11F1O2 with the atom numbering scheme. The thermal ellipsoids are drawn at the 50% probability level. H-atoms are shown by small circles of arbitrary radii.

Fig. 2.

The packing figure (PLATON: Spek, 2003) which shows the dimeric nature of the compound owing to inter molecular hydrogen bonding and also showing a link between dimers.

Crystal data

C11H11F1O2	F000 = 408
Mr = 194.20	Dx = 1.287 Mg m−3
Monoclinic, P21/c	Mo Kα radiation radiation λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2981 reflections
a = 4.1895 (4) Å	θ = 2.3–30.6º
b = 17.4362 (19) Å	µ = 0.10 mm−1
c = 13.8134 (15) Å	T = 296 (2) K
β = 96.719 (3)º	Prismatic, colourless
V = 1002.12 (18) Å3	0.25 × 0.18 × 0.12 mm
Z = 4

Data collection

Bruker KappaAPEXII CCD diffractometer	2981 independent reflections
Radiation source: fine-focus sealed tube	1704 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.026
Detector resolution: 7.2 pixels mm-1	θmax = 30.6º
T = 296(2) K	θmin = 2.3º
ω scans	h = −5→6
Absorption correction: multi-scan(SADABS; Bruker, 2005)	k = −24→23
Tmin = 0.935, Tmax = 0.958	l = −19→19
8632 measured reflections

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.050	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.164	w = 1/[σ2(Fo2) + (0.0731P)2 + 0.1527P] where P = (Fo2 + 2Fc2)/3
S = 1.04	(Δ/σ)max < 0.001
2981 reflections	Δρmax = 0.41 e Å−3
131 parameters	Δρmin = −0.21 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

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
F1	0.5705 (5)	0.28288 (7)	0.22076 (10)	0.1113 (6)
O1	1.0669 (3)	0.08331 (7)	0.07503 (9)	0.0575 (4)
H1	1.104 (5)	0.0617 (11)	0.0126 (15)	0.069*
O2	0.8191 (3)	−0.02692 (7)	0.09434 (9)	0.0609 (4)
C1	0.8986 (4)	0.03770 (8)	0.12367 (11)	0.0406 (4)
C2	0.8045 (3)	0.06721 (8)	0.21699 (11)	0.0394 (4)
C3	0.8530 (4)	0.14131 (9)	0.23791 (12)	0.0443 (4)
H3	0.9555	0.1699	0.1938	0.053*
C4	0.7616 (4)	0.18258 (9)	0.32326 (11)	0.0449 (4)
C5	0.6226 (5)	0.25413 (10)	0.31195 (13)	0.0593 (5)
C6	0.5260 (6)	0.29671 (11)	0.38672 (16)	0.0705 (6)
H6	0.4286	0.3443	0.3749	0.085*
C7	0.5763 (6)	0.26755 (11)	0.47922 (15)	0.0659 (6)
H7	0.5120	0.2953	0.5311	0.079*
C8	0.7214 (5)	0.19750 (12)	0.49543 (14)	0.0691 (6)
H8	0.7586	0.1781	0.5585	0.083*
C9	0.8126 (5)	0.15554 (11)	0.41831 (13)	0.0601 (5)
H9	0.9105	0.1081	0.4304	0.072*
C10	0.6348 (4)	0.01081 (9)	0.27580 (12)	0.0458 (4)
H10A	0.4779	−0.0170	0.2319	0.055*
H10B	0.5185	0.0392	0.3209	0.055*
C11	0.8524 (5)	−0.04706 (11)	0.33354 (14)	0.0614 (5)
H11A	0.7248	−0.0808	0.3682	0.092*
H11B	1.0041	−0.0205	0.3791	0.092*
H11C	0.9657	−0.0764	0.2897	0.092*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
F1	0.2170 (19)	0.0646 (8)	0.0569 (8)	0.0505 (10)	0.0350 (9)	0.0161 (6)
O1	0.0854 (9)	0.0450 (7)	0.0468 (7)	−0.0124 (6)	0.0275 (6)	−0.0072 (5)
O2	0.0912 (10)	0.0434 (7)	0.0528 (7)	−0.0149 (6)	0.0288 (7)	−0.0118 (5)
C1	0.0485 (8)	0.0360 (8)	0.0382 (8)	0.0015 (6)	0.0091 (7)	0.0007 (6)
C2	0.0426 (8)	0.0401 (8)	0.0357 (7)	0.0046 (6)	0.0061 (6)	0.0003 (6)
C3	0.0549 (9)	0.0404 (8)	0.0382 (8)	0.0029 (6)	0.0085 (7)	−0.0005 (6)
C4	0.0575 (10)	0.0386 (8)	0.0393 (8)	0.0012 (7)	0.0088 (7)	−0.0041 (6)
C5	0.0947 (14)	0.0413 (9)	0.0438 (10)	0.0086 (9)	0.0156 (9)	0.0029 (7)
C6	0.1047 (17)	0.0438 (10)	0.0653 (13)	0.0165 (10)	0.0194 (12)	−0.0084 (9)
C7	0.0898 (15)	0.0588 (12)	0.0521 (11)	0.0015 (10)	0.0203 (10)	−0.0183 (9)
C8	0.0999 (16)	0.0685 (13)	0.0391 (9)	0.0122 (11)	0.0095 (10)	−0.0042 (9)
C9	0.0866 (14)	0.0525 (10)	0.0406 (9)	0.0170 (9)	0.0047 (9)	−0.0027 (8)
C10	0.0478 (9)	0.0460 (9)	0.0456 (9)	−0.0026 (7)	0.0136 (7)	−0.0018 (7)
C11	0.0694 (12)	0.0513 (10)	0.0654 (12)	−0.0014 (8)	0.0163 (10)	0.0179 (9)

Geometric parameters (Å, °)

F1—C5	1.350 (2)	C6—H6	0.9300
O1—C1	1.3006 (18)	C7—C8	1.371 (3)
O1—H1	0.97 (2)	C7—H7	0.9300
O2—C1	1.2301 (18)	C8—C9	1.383 (2)
C1—C2	1.483 (2)	C8—H8	0.9300
C2—C3	1.334 (2)	C9—H9	0.9300
C2—C10	1.506 (2)	C10—C11	1.521 (2)
C3—C4	1.470 (2)	C10—H10A	0.9700
C3—H3	0.9300	C10—H10B	0.9700
C4—C5	1.378 (2)	C11—H11A	0.9600
C4—C9	1.388 (2)	C11—H11B	0.9600
C5—C6	1.371 (3)	C11—H11C	0.9600
C6—C7	1.368 (3)
C1—O1—H1	112.0 (12)	C6—C7—H7	120.0
O2—C1—O1	122.15 (14)	C8—C7—H7	120.0
O2—C1—C2	120.97 (14)	C7—C8—C9	120.19 (18)
O1—C1—C2	116.88 (13)	C7—C8—H8	119.9
C3—C2—C1	118.35 (14)	C9—C8—H8	119.9
C3—C2—C10	125.80 (14)	C8—C9—C4	121.56 (17)
C1—C2—C10	115.63 (13)	C8—C9—H9	119.2
C2—C3—C4	126.91 (15)	C4—C9—H9	119.2
C2—C3—H3	116.5	C2—C10—C11	115.09 (14)
C4—C3—H3	116.5	C2—C10—H10A	108.5
C5—C4—C9	115.53 (15)	C11—C10—H10A	108.5
C5—C4—C3	119.92 (15)	C2—C10—H10B	108.5
C9—C4—C3	124.53 (14)	C11—C10—H10B	108.5
F1—C5—C6	118.18 (17)	H10A—C10—H10B	107.5
F1—C5—C4	117.52 (16)	C10—C11—H11A	109.5
C6—C5—C4	124.27 (18)	C10—C11—H11B	109.5
C7—C6—C5	118.38 (18)	H11A—C11—H11B	109.5
C7—C6—H6	120.8	C10—C11—H11C	109.5
C5—C6—H6	120.8	H11A—C11—H11C	109.5
C6—C7—C8	120.03 (18)	H11B—C11—H11C	109.5
O2—C1—C2—C3	−169.70 (16)	C3—C4—C5—C6	179.3 (2)
O1—C1—C2—C3	10.1 (2)	F1—C5—C6—C7	179.6 (2)
O2—C1—C2—C10	5.2 (2)	C4—C5—C6—C7	1.5 (4)
O1—C1—C2—C10	−174.93 (14)	C5—C6—C7—C8	0.3 (4)
C1—C2—C3—C4	176.46 (15)	C6—C7—C8—C9	−1.0 (4)
C10—C2—C3—C4	2.1 (3)	C7—C8—C9—C4	0.1 (3)
C2—C3—C4—C5	−136.30 (19)	C5—C4—C9—C8	1.5 (3)
C2—C3—C4—C9	45.5 (3)	C3—C4—C9—C8	179.80 (19)
C9—C4—C5—F1	179.57 (19)	C3—C2—C10—C11	−106.93 (19)
C3—C4—C5—F1	1.2 (3)	C1—C2—C10—C11	78.57 (19)
C9—C4—C5—C6	−2.4 (3)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2i	0.97 (2)	1.66 (2)	2.6325 (18)	177.7 (12)
C3—H3···O1	0.93	2.32	2.713 (2)	105
C6—H6···O2ii	0.93	2.53	3.421 (2)	160
C8—H8···F1iii	0.93	2.55	3.266 (2)	134 (1)

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