2-(4-Ethoxy­benzyl­idene)butanoic acid

Niaz Muhammad; M Nawaz Tahir; Zia-ur-Rehman; Saqib Ali

doi:10.1107/S160053680802103X

. 2008 Jul 12;64(Pt 8):o1458. doi: 10.1107/S160053680802103X

2-(4-Ethoxybenzylidene)butanoic acid

Niaz Muhammad ^a, M Nawaz Tahir ^b,^*, Zia-ur-Rehman ^a, Saqib Ali ^a

PMCID: PMC2961990 PMID: 21203172

Abstract

In the crystal structure of the title compound, C₁₃H₁₆O₃, dimers are formed due to intermolecular O—H⋯O hydrogen bonding. There exists an intramolecular C—H⋯O hydrogen bond which forms a five-membered ring. There is also present a C—H⋯π interaction between a methyl CH group of an ethyl group and the centroid of the aromatic ring.

Related literature

For related literature, see: Bernstein et al. (1995 ▶); Burt (2004 ▶); Muhammad et al. (2007 ▶, 2008a ▶,b ▶,c ▶); Niaz et al. (2008 ▶).

Experimental

Crystal data

C₁₃H₁₆O₃
M _r = 220.26
Monoclinic,
a = 10.3192 (7) Å
b = 22.0761 (15) Å
c = 5.2362 (3) Å
β = 100.751 (4)°
V = 1171.91 (13) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 296 (2) K
0.26 × 0.20 × 0.16 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.975, T _max = 0.985
13990 measured reflections
3009 independent reflections
1599 reflections with I > 2σ(I)
R _int = 0.049

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.122
S = 1.00
3009 reflections
150 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.14 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

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680802103X/at2588sup1.cif

e-64-o1458-sup1.cif^{(16.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680802103X/at2588Isup2.hkl

e-64-o1458-Isup2.hkl^{(144.7KB, hkl)}

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	1.01 (2)	1.61 (2)	2.6184 (15)	176.8 (15)
C7—H7⋯O1	0.93	2.30	2.7218 (19)	107
C12—H12B⋯CgAⁱⁱ	0.96	2.82	3.6534 (19)	145

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Symmetry codes: (i) Inline graphic ; (ii) . CgA is the centroid of the C1–C6 ring.

Acknowledgments

The authors acknowledge the Higher Education Commission, Islamabad, Pakistan, for funding the purchase of the diffractometer at GCU, Lahore, and for financial support to NM for PhD studies under the Indigenous Scholarship Scheme.

supplementary crystallographic information

Comment

Cinnamic acid derivatives play an important role in the production of lignins for higher plants. They are well documented for their antibacterial, antifungal and antiparasitic activities (Burt, 2004). We have recently reported the various derivatives of cinamic acids (Niaz et al., 2008, Muhammad et al., 2008a) and tin complexes (Muhammad et al., 2008b, 2008c). In continuation of our project, we herein report the structure of the title compound (I).

The crystal structure of 3-(4-bromophenyl)-2-ethylacrylic acid (II) (Muhammad et al., 2007) differs from (I) due to the attachement of ethoxy group at para position instead of Br-atom. Similarly, (E) -2-(2-fluorobenzylidene) butanoic acid (III) (Niaz et al., 2008) differs as the attachment of F-atom is on meta position. Thus, (I) is very different from the reported compounds (II) and (III).

In the crystal structure of the title compound (I), the C—C bonds are in the range 1.464 (2) to 1.511 (2) Å, and C═C have a value of 1.337 (2) Å. The value of C—O bond in the carboxylate group is 1.287 (2) Å, whereas C═O is of 1.248 (2) Å. The attached ethoxy group have 1.3595 (19) and 1.431 (2) Å as the C—O bond distances. In the asymmetric unit, there is an interamolecular H-bond of C—H···O type (Table 1, Fig 1) which completes a five membered ring (O1/C9/C8/C7/H7). Centrosymmetric dimers, R₂²(8) (Bernstein et al. 1995) are formed due to the intermolecular hydrogen bonding, O1—H1···O2ⁱ [symmetry code: (i) = -x + 1, -y, -z - 1]. These dimers have a π-interaction C12—H12B···CgAⁱⁱ [symmetry code: (ii) = x, y, z + 1] where CgA is the centroid of the aromatic ring A(C1—C6). The dihedral angle between (O1/C9/O2) and (C8/C10/C11) is 75.55 (15)°, whereas it is 30.19 (17)° between (C7/C8/C9) and (O3/C12/C13). The ethoxy group makes a dihedral angle of 2.77 (11)° with the aromatic ring. The formation of centrosymmetric dimers and packing of (I) is shown in Fig 2.

Experimental

Compound (I) was prepared according to the reported procedure (Muhammad et al., 2007). A mixture of 4-ethoxybenzaldehyde(1.39 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 [yield: 66%].