2-(Acet­oxy­meth­yl)benzoic acid

Abstract

The title compound, C₁₀H₁₀O₄, crystallizes with the well-known carb­oxy­lic acid dimer-forming R ₂ ²(8) hydrogen-bond motif. Chains approximately parallel to (-1-12) are then built through C(methyl­ene,phen­yl)–H⋯O(carbon­yl) inter­actions [C(6) and C(8) motifs] with one (meth­yl)C—H⋯π inter­action providing inter­planar binding. The weakness of the latter inter­action is consistent with the difficulty experienced in obtaining suitable single crystals.

Related literature  

For details of the synthesis, see: Gorter-Laroij & Kooyman (1972 ▶). For related structures, see Kan et al. (2012 ▶); Liu et al. (2002 ▶); Valentine et al. (1992 ▶). For hydrogen-bonding motifs, see: Bernstein et al. (1995 ▶). For a description of the Cambridge Structural Database (CSD), see: Allen (2002 ▶).

Experimental  

Crystal data  

• C₁₀H₁₀O₄

• M _r = 194.18

• Triclinic,

• a = 6.2134 (9) Å

• b = 8.2415 (9) Å

• c = 9.6280 (11) Å

• α = 77.54 (1)°

• β = 83.364 (11)°

• γ = 73.081 (12)°

• V = 459.84 (10) ų

• Z = 2

• Cu Kα radiation

• μ = 0.92 mm⁻¹

• T = 120 K

• 0.58 × 0.28 × 0.18 mm

Data collection  

• Oxford Diffraction SuperNova diffractometer

• Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2007 ▶) T _min = 0.848, T _max = 1.000

• 2819 measured reflections

• 1767 independent reflections

• 1678 reflections with I > 2σ(I)

• R _int = 0.012

Refinement  

• R[F ² > 2σ(F ²)] = 0.033

• wR(F ²) = 0.093

• S = 1.08

• 1767 reflections

• 131 parameters

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

• Δρ_max = 0.22 e Å⁻³

• Δρ_min = −0.19 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2007 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP in WinGX (Farrugia, 2012 ▶) and Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

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

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

Cg1 is the centroid of the C1–C6 phenyl ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O1i	0.971 (16)	1.667 (15)	2.6316 (12)	171.6 (12)
C4—H4⋯O4ii	0.95	2.43	3.3685 (15)	168
C8—H8A⋯O2iii	0.99	2.67	3.5747 (14)	152
C10—H10B⋯Cg1iii	0.98	2.82	3.5703 (13)	134

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

supplementary crystallographic information

Comment

The title compound was synthesized during our studies on substituted benzoyl protecting groups that could be selectively cleaved in the presence of other benzoate esters. We believe the structure has not been reported previously because of difficulties, which we experienced, in obtaining suitable non-twinned single crystals and the tendency of the title compound to cyclize with formation of phthalide. The compound crystallizes with one independent C₁₀H₁₀O₄ molecule in the asymmetric unit (Fig. 1). Only two closely related structures with similar carboxylic acid hydrogen bonding links [R²₂(8) (Bernstein et al.,1995)] were found in the CSD (Allen, 2002): JOWTIY (Valentine et al., 1992) and UHELOI (Liu et al., 2002). The rather short intermolecular H2···O1 contact distance [1.667 (15) Å] (Table 1) is replicated in these two reports as 1.752 & 1.569 Å, respectively. A series of metal complexes containing the acetoxymethyl- moiety have been reported by Kan et al. (2012).

The crystal packing (Table 1) consists of the above-mentioned strong carboxylic acid hydrogen bonding in the plane of the molecule. This is coupled with C(methylene,phenyl)—H···O(carbonyl) interactions [C(6) & C(8) motifs] forming planar chains. One weak (methyl)C8—H10B···π interaction (labelled in Figure 2) crosslinks the planes of molecules, which are approximately parallel to the (-1,-1,2) crystal plane. This weak interplanar interaction is consistent with the difficulty in obtaining adequate non-twinned crystals.

Experimental

The synthesis of the title compound has been reported previously by Gorter-Laroij & Kooyman (1972). Crystals for analysis were obtained by dissolving the title compound in a minimal amount of ethyl acetate, followed by addition of petroleum ether 60–80.

Refinement

Eight outlier reflections, identified by large delta/sigma ratio (>4.8), were OMITted from the dataset (four were omitted on the basis of inconsistent equivalents). All methyl H atoms were constrained to an ideal geometry (C—H = 0.98 Å) with U_iso(H) = 1.5U_eq(C), but were allowed to rotate freely about the adjacent C—C bond. All other C bound H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with C—H distances of 1.00 (primary), 0.99 (methylene) or 0.95 (phenyl) Å and with U_iso(H) = 1.2U_eq(C). The hydroxyl hydrogen on O2 was refined with U_iso(H) = 1.2U_eq(O2)

Figures

Fig. 1.

ORTEP view of the asymmetric unit with 30% ellipsoid probabilities. H atoms are of arbitrary size.

Fig. 2.

Cell contents view down the c axis. Contact atoms are shown as balls; intermolecular bonding contacts are shown as blue dotted lines. Symmetry: (i) 1 - x,2 - y, 1 - z (ii) 1 - x, 1 - y, 1 - z (iii) 2 - x, 1 - y, 1 - z.

Crystal data

C10H10O4	Z = 2
Mr = 194.18	F(000) = 204
Triclinic, P1	Dx = 1.402 Mg m−3
Hall symbol: -P 1	Cu Kα radiation, λ = 1.54184 Å
a = 6.2134 (9) Å	Cell parameters from 1939 reflections
b = 8.2415 (9) Å	θ = 4.7–73.5°
c = 9.6280 (11) Å	µ = 0.92 mm−1
α = 77.54 (1)°	T = 120 K
β = 83.364 (11)°	Plate, colourless
γ = 73.081 (12)°	0.58 × 0.28 × 0.18 mm
V = 459.84 (10) Å3

Data collection

Oxford Diffraction SuperNova diffractometer	1767 independent reflections
Radiation source: fine-focus sealed tube	1678 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.012
Detector resolution: 10.6501 pixels mm-1	θmax = 73.6°, θmin = 8.1°
ω scans	h = −7→5
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2007)	k = −10→9
Tmin = 0.848, Tmax = 1.000	l = −11→10
2819 measured reflections

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.093	H atoms treated by a mixture of independent and constrained refinement
S = 1.08	w = 1/[σ2(Fo2) + (0.0557P)2 + 0.0727P] where P = (Fo2 + 2Fc2)/3
1767 reflections	(Δ/σ)max < 0.001
131 parameters	Δρmax = 0.22 e Å−3
0 restraints	Δρmin = −0.19 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	0.36320 (13)	0.93020 (10)	0.39619 (8)	0.0303 (2)
O2	0.71012 (13)	0.80677 (11)	0.47419 (8)	0.0317 (2)
H2	0.671 (2)	0.909 (2)	0.5167 (15)	0.038*
O3	0.07354 (12)	0.72594 (9)	0.12998 (8)	0.0267 (2)
O4	−0.20437 (13)	0.97266 (10)	0.12417 (8)	0.0313 (2)
C1	0.56622 (17)	0.65287 (13)	0.34491 (11)	0.0249 (2)
C2	0.40134 (17)	0.63516 (13)	0.26421 (10)	0.0239 (2)
C3	0.44020 (18)	0.48029 (14)	0.21710 (11)	0.0285 (2)
H3	0.3306	0.4661	0.1631	0.034*
C4	0.6346 (2)	0.34570 (15)	0.24670 (13)	0.0325 (3)
H4	0.6559	0.2413	0.2136	0.039*
C5	0.79735 (19)	0.36433 (15)	0.32480 (12)	0.0330 (3)
H5	0.9310	0.2733	0.3451	0.040*
C6	0.76242 (19)	0.51722 (15)	0.37275 (12)	0.0307 (3)
H6	0.8741	0.5304	0.4257	0.037*
C7	0.53578 (17)	0.80933 (14)	0.40604 (11)	0.0260 (2)
C8	0.18911 (17)	0.77882 (13)	0.22692 (11)	0.0251 (2)
H8A	0.0919	0.7988	0.3140	0.030*
H8B	0.2274	0.8874	0.1812	0.030*
C9	−0.12281 (17)	0.83631 (13)	0.08618 (11)	0.0246 (2)
C10	−0.22257 (18)	0.76614 (14)	−0.01435 (12)	0.0291 (3)
H10A	−0.3748	0.8401	−0.0347	0.044*
H10B	−0.2297	0.6487	0.0291	0.044*
H10C	−0.1284	0.7637	−0.1033	0.044*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0287 (4)	0.0314 (4)	0.0345 (4)	−0.0057 (3)	−0.0068 (3)	−0.0149 (3)
O2	0.0268 (4)	0.0386 (5)	0.0348 (4)	−0.0073 (3)	−0.0075 (3)	−0.0172 (3)
O3	0.0254 (4)	0.0252 (4)	0.0323 (4)	−0.0038 (3)	−0.0085 (3)	−0.0120 (3)
O4	0.0306 (4)	0.0274 (4)	0.0362 (4)	−0.0014 (3)	−0.0064 (3)	−0.0129 (3)
C1	0.0251 (5)	0.0287 (5)	0.0217 (5)	−0.0074 (4)	−0.0017 (4)	−0.0066 (4)
C2	0.0247 (5)	0.0262 (5)	0.0218 (5)	−0.0079 (4)	−0.0011 (4)	−0.0060 (4)
C3	0.0294 (5)	0.0280 (5)	0.0306 (5)	−0.0073 (4)	−0.0049 (4)	−0.0098 (4)
C4	0.0351 (6)	0.0269 (5)	0.0347 (6)	−0.0035 (4)	−0.0035 (5)	−0.0104 (4)
C5	0.0296 (6)	0.0316 (6)	0.0329 (6)	0.0011 (4)	−0.0052 (4)	−0.0073 (4)
C6	0.0270 (5)	0.0376 (6)	0.0276 (5)	−0.0056 (4)	−0.0057 (4)	−0.0086 (4)
C7	0.0259 (5)	0.0325 (5)	0.0225 (5)	−0.0100 (4)	−0.0027 (4)	−0.0076 (4)
C8	0.0257 (5)	0.0262 (5)	0.0273 (5)	−0.0073 (4)	−0.0056 (4)	−0.0110 (4)
C9	0.0234 (5)	0.0260 (5)	0.0248 (5)	−0.0064 (4)	−0.0019 (4)	−0.0058 (4)
C10	0.0282 (5)	0.0317 (5)	0.0301 (5)	−0.0072 (4)	−0.0060 (4)	−0.0103 (4)

Geometric parameters (Å, º)

O1—C7	1.2297 (14)	C3—H3	0.9500
O2—C7	1.3226 (12)	C4—C5	1.3885 (16)
O2—H2	0.974 (16)	C4—H4	0.9500
O3—C9	1.3421 (13)	C5—C6	1.3844 (17)
O3—C8	1.4454 (11)	C5—H5	0.9500
O4—C9	1.2068 (13)	C6—H6	0.9500
C1—C6	1.4003 (15)	C8—H8A	0.9900
C1—C2	1.4123 (14)	C8—H8B	0.9900
C1—C7	1.4848 (15)	C9—C10	1.4981 (14)
C2—C3	1.3922 (15)	C10—H10A	0.9800
C2—C8	1.5122 (14)	C10—H10B	0.9800
C3—C4	1.3905 (16)	C10—H10C	0.9800
C7—O2—H2	108.3 (8)	C1—C6—H6	119.3
C9—O3—C8	116.34 (8)	O1—C7—O2	122.58 (10)
C6—C1—C2	119.53 (10)	O1—C7—C1	123.34 (9)
C6—C1—C7	118.30 (10)	O2—C7—C1	114.07 (9)
C2—C1—C7	122.14 (9)	O3—C8—C2	107.39 (8)
C3—C2—C1	117.96 (10)	O3—C8—H8A	110.2
C3—C2—C8	119.97 (9)	C2—C8—H8A	110.2
C1—C2—C8	122.07 (9)	O3—C8—H8B	110.2
C4—C3—C2	122.02 (10)	C2—C8—H8B	110.2
C4—C3—H3	119.0	H8A—C8—H8B	108.5
C2—C3—H3	119.0	O4—C9—O3	123.58 (9)
C5—C4—C3	119.84 (10)	O4—C9—C10	125.78 (9)
C5—C4—H4	120.1	O3—C9—C10	110.65 (9)
C3—C4—H4	120.1	C9—C10—H10A	109.5
C6—C5—C4	119.18 (10)	C9—C10—H10B	109.5
C6—C5—H5	120.4	H10A—C10—H10B	109.5
C4—C5—H5	120.4	C9—C10—H10C	109.5
C5—C6—C1	121.47 (10)	H10A—C10—H10C	109.5
C5—C6—H6	119.3	H10B—C10—H10C	109.5
C6—C1—C2—C3	0.99 (15)	C7—C1—C6—C5	176.98 (10)
C7—C1—C2—C3	−176.96 (9)	C6—C1—C7—O1	−174.82 (10)
C6—C1—C2—C8	−178.20 (9)	C2—C1—C7—O1	3.15 (16)
C7—C1—C2—C8	3.86 (15)	C6—C1—C7—O2	4.31 (14)
C1—C2—C3—C4	−0.29 (16)	C2—C1—C7—O2	−177.72 (9)
C8—C2—C3—C4	178.91 (10)	C9—O3—C8—C2	178.87 (8)
C2—C3—C4—C5	−0.38 (17)	C3—C2—C8—O3	−6.19 (13)
C3—C4—C5—C6	0.34 (17)	C1—C2—C8—O3	172.98 (9)
C4—C5—C6—C1	0.37 (18)	C8—O3—C9—O4	−0.53 (14)
C2—C1—C6—C5	−1.05 (17)	C8—O3—C9—C10	179.49 (8)

Hydrogen-bond geometry (Å, º)

Cg1 is the centroid of the C1–C6 phenyl ring.

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1i	0.971 (16)	1.667 (15)	2.6316 (12)	171.6 (12)
C4—H4···O4ii	0.95	2.43	3.3685 (15)	168
C8—H8A···O2iii	0.99	2.67	3.5747 (14)	152
C10—H10B···Cg1iii	0.98	2.82	3.5703 (13)	134

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