2-(3-Bromo-4-ethyl­phen­yl)-2-methyl­propanoic acid

Sun, R.; Yang, X.-Y.; Yao, C.

doi:10.1107/S1600536809036769

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 65| Part 10| October 2009| Page o2481

doi:10.1107/S1600536809036769

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2-(3-Bromo-4-ethylphenyl)-2-methylpropanoic acid

Rong Sun,^a Xiao-Yan Yang ^b and Cheng Yao ^a ^*

^aDepartment of Applied Chemistry, College of Science, Nanjing University of Technology, Nanjing 210009, People's Republic of China, and ^bDepartment of Chemical Engineering, Nanjing College of Chemical Technology, Nanjing 210048, People's Republic of China
^*Correspondence e-mail: yaocheng@njut.edu.cn

(Received 7 September 2009; accepted 11 September 2009; online 16 September 2009)

In the title compound, C₁₂H₁₅BrO₂, the carboxyl group forms a dihedral angle of 78.4 (3)° with the benzene ring plane. In the crystal, molecules are linked into centrosymmetric dimers by pairs of O—H⋯O hydrogen bonds.

Related literature

For the preparation of pharmaceuticals and active agrochemical ingredients using 2-(3-bromo-4-ethylphenyl)-2-methylpropanoic acid, see: Wiegand et al. (2007 ). For bond-length data, see: Allen et al. (1987 ).

Experimental

Crystal data

C₁₂H₁₅BrO₂
M_r = 271.15
Monoclinic, P 2₁ /n
a = 9.7370 (19) Å
b = 7.2930 (15) Å
c = 17.433 (4) Å
β = 90.98 (3)°
V = 1237.8 (4) Å³
Z = 4
Mo Kα radiation
μ = 3.30 mm⁻¹
T = 298 K
0.20 × 0.10 × 0.10 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.558, T_max = 0.734
2389 measured reflections
2246 independent reflections
1171 reflections with I > 2σ(I)
R_int = 0.051
3 standard reflections every 200 reflections intensity decay: 1%

Refinement

R[F² > 2σ(F²)] = 0.065
wR(F²) = 0.157
S = 1.00
2246 reflections
136 parameters
H-atom parameters constrained
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.56 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1D⋯O2ⁱ	0.82	1.88	2.696 (6)	178
Symmetry code: (i) -x, -y, -z.

Data collection: CAD-4 Software (Enraf–Nonius, 1985 ); cell refinement: CAD-4 Software; 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: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, ls. DOI: 10.1107/S1600536809036769/ci2903sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809036769/ci2903Isup2.hkl

checkCIF report

Comment top

2-(3-Bromo-4-ethylphenyl)-2-methylpropanoic acid is one of the valuable intermediates for the preparation of pharmaceuticals and active agrochemical ingredients (Wiegand et al., 2007). We report here the crystal structure of the title compound.

Bond lengths (Allen et al., 1987) and angles in the title molecule (Fig.1) are within normal ranges. The plane of the carboxyl group forms a dihedral angle of 78.4 (3)° with the benzene plane.

In the crystal, molecules are linked into centrosymmetric dimers by pairs of O—H···O hydrogen bonds (Fig. 2).

Related literature top

For the preparation of pharmaceuticals and active agrochemical ingredients using 2-(3-bromo-4-ethylphenyl)-2-methylpropanoic acid, see: Wiegand et al. (2007). For bond-length data, see: Allen et al. (1987).

Experimental top

The title compound was prepared by the hydrolyzation of methyl 2-(3-bromo-4-ethylphenyl)-2-methylpropanoate (10.42 g, 0.037 mol) in a solution of methanol (30 ml) and acetone (150 ml), catalyzed by KOH aqueous solution (73 ml, 1.0 mol/l) at room temperature (298 k). After stirring for 8 h, methanol and acetone were removed by reduced distillation to obtain an aqueous substrate. The substrate was washed with dichloromethane (4× 20 ml), and precipitated with concentrated hydrochloric acid. Then the precipitate was washed with water, collected and dried to give 2-(3-bromo-4-ethylphenyl)-2-methylpropanoic acid (4.07 g, 0.015 mol) with a yield of 41.0%. Single crystals of the compound were obtained by slow evaporation of an methanol solution at room temperature.

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1985); cell refinement: CAD-4 Software (Enraf–Nonius, 1985); 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: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of the title compound, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A packing diagram of the title compound. Hydrogen bonds are shown as dashed lines.

2-(3-Bromo-4-ethylphenyl)-2-methylpropanoic acid top

Crystal data top

C₁₂H₁₅BrO₂	F(000) = 552
M_r = 271.15	D_x = 1.455 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 25 reflections
a = 9.7370 (19) Å	θ = 10–13°
b = 7.2930 (15) Å	µ = 3.30 mm⁻¹
c = 17.433 (4) Å	T = 298 K
β = 90.98 (3)°	Block, colourless
V = 1237.8 (4) Å³	0.20 × 0.10 × 0.10 mm
Z = 4

Data collection top

Enraf–Nonius CAD-4 diffractometer	1171 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.051
Graphite monochromator	θ_max = 25.3°, θ_min = 2.4°
ω/2θ scans	h = 0→11
Absorption correction: ψ scan (North et al., 1968)	k = 0→8
T_min = 0.558, T_max = 0.734	l = −20→20
2389 measured reflections	3 standard reflections every 200 reflections
2246 independent reflections	intensity decay: 1%

Refinement top

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)] = 0.065	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.157	H-atom parameters constrained
S = 1.00	w = 1/[σ²(F_o²) + (0.073P)²] where P = (F_o² + 2F_c²)/3
2246 reflections	(Δ/σ)_max = 0.001
136 parameters	Δρ_max = 0.37 e Å⁻³
0 restraints	Δρ_min = −0.56 e Å⁻³

Crystal data top

C₁₂H₁₅BrO₂	V = 1237.8 (4) Å³
M_r = 271.15	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 9.7370 (19) Å	µ = 3.30 mm⁻¹
b = 7.2930 (15) Å	T = 298 K
c = 17.433 (4) Å	0.20 × 0.10 × 0.10 mm
β = 90.98 (3)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	1171 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.051
T_min = 0.558, T_max = 0.734	3 standard reflections every 200 reflections
2389 measured reflections	intensity decay: 1%
2246 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.065	0 restraints
wR(F²) = 0.157	H-atom parameters constrained
S = 1.00	Δρ_max = 0.37 e Å⁻³
2246 reflections	Δρ_min = −0.56 e Å⁻³
136 parameters

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
Br	0.59774 (8)	0.20831 (13)	0.22133 (4)	0.0837 (4)
O1	0.1885 (4)	0.0103 (6)	0.0039 (3)	0.0702 (14)
H1D	0.1216	−0.0561	0.0099	0.105*
C1	0.5163 (8)	0.6662 (12)	0.2979 (4)	0.095 (3)
H1A	0.5349	0.6986	0.3504	0.142*
H1B	0.4845	0.7723	0.2703	0.142*
H1C	0.5988	0.6212	0.2751	0.142*
O2	0.0282 (4)	0.2132 (6)	−0.0248 (3)	0.0621 (12)
C2	0.4083 (6)	0.5204 (10)	0.2946 (3)	0.0651 (19)
H2A	0.3259	0.5656	0.3186	0.078*
H2B	0.4402	0.4145	0.3234	0.078*
C3	0.3738 (6)	0.4625 (9)	0.2136 (3)	0.0456 (15)
C4	0.4468 (5)	0.3321 (9)	0.1736 (3)	0.0453 (15)
C5	0.4157 (5)	0.2833 (8)	0.0980 (3)	0.0420 (14)
H5A	0.4688	0.1960	0.0733	0.050*
C6	0.3068 (5)	0.3641 (8)	0.0596 (3)	0.0376 (14)
C7	0.2310 (6)	0.4946 (9)	0.0993 (3)	0.0551 (17)
H7A	0.1569	0.5521	0.0751	0.066*
C8	0.2650 (6)	0.5387 (9)	0.1738 (4)	0.0585 (18)
H8A	0.2115	0.6251	0.1987	0.070*
C9	0.2652 (6)	0.3128 (8)	−0.0232 (3)	0.0458 (15)
C10	0.3853 (7)	0.2252 (10)	−0.0659 (4)	0.069 (2)
H10A	0.3562	0.1951	−0.1173	0.103*
H10B	0.4141	0.1157	−0.0397	0.103*
H10C	0.4605	0.3102	−0.0675	0.103*
C11	0.2130 (7)	0.4781 (9)	−0.0680 (4)	0.067 (2)
H11A	0.1368	0.5316	−0.0419	0.100*
H11B	0.1840	0.4401	−0.1185	0.100*
H11C	0.2853	0.5669	−0.0720	0.100*
C12	0.1475 (6)	0.1738 (8)	−0.0153 (3)	0.0456 (15)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br	0.0699 (5)	0.1100 (7)	0.0703 (5)	0.0306 (5)	−0.0219 (4)	0.0089 (5)
O1	0.055 (3)	0.041 (3)	0.113 (4)	−0.007 (2)	−0.016 (3)	0.011 (3)
C1	0.103 (6)	0.102 (7)	0.078 (5)	−0.038 (6)	−0.012 (5)	−0.032 (5)
O2	0.046 (3)	0.046 (3)	0.094 (3)	−0.001 (2)	−0.016 (2)	0.007 (2)
C2	0.063 (4)	0.082 (5)	0.050 (4)	−0.007 (4)	0.000 (3)	−0.003 (4)
C3	0.042 (3)	0.053 (4)	0.041 (3)	−0.003 (3)	−0.002 (3)	−0.005 (3)
C4	0.035 (3)	0.054 (4)	0.047 (3)	−0.007 (3)	−0.002 (3)	0.010 (3)
C5	0.041 (3)	0.040 (3)	0.045 (3)	0.004 (3)	0.002 (3)	0.000 (3)
C6	0.038 (3)	0.036 (3)	0.039 (3)	−0.005 (3)	0.001 (3)	0.001 (3)
C7	0.046 (4)	0.065 (5)	0.054 (4)	0.011 (3)	−0.013 (3)	−0.006 (4)
C8	0.059 (4)	0.054 (5)	0.062 (4)	0.009 (3)	−0.003 (3)	−0.019 (3)
C9	0.048 (3)	0.048 (4)	0.041 (3)	0.000 (3)	−0.005 (3)	−0.001 (3)
C10	0.067 (4)	0.090 (6)	0.049 (4)	0.000 (4)	0.008 (3)	−0.009 (4)
C11	0.089 (5)	0.064 (5)	0.047 (4)	−0.014 (4)	−0.017 (4)	0.013 (4)
C12	0.057 (4)	0.034 (4)	0.045 (3)	0.001 (3)	−0.011 (3)	−0.001 (3)

Geometric parameters (Å, º) top

Br—C4	1.904 (6)	C5—H5A	0.93
O1—C12	1.299 (7)	C6—C7	1.395 (8)
O1—H1D	0.82	C6—C9	1.539 (7)
C1—C2	1.496 (9)	C7—C8	1.373 (8)
C1—H1A	0.96	C7—H7A	0.93
C1—H1B	0.96	C8—H8A	0.93
C1—H1C	0.96	C9—C11	1.520 (8)
O2—C12	1.205 (7)	C9—C10	1.536 (9)
C2—C3	1.505 (8)	C9—C12	1.538 (8)
C2—H2A	0.97	C10—H10A	0.96
C2—H2B	0.97	C10—H10B	0.96
C3—C8	1.374 (8)	C10—H10C	0.96
C3—C4	1.383 (8)	C11—H11A	0.96
C4—C5	1.394 (8)	C11—H11B	0.96
C5—C6	1.376 (7)	C11—H11C	0.96

C12—O1—H1D	109.5	C8—C7—H7A	119.7
C2—C1—H1A	109.5	C6—C7—H7A	119.7
C2—C1—H1B	109.5	C7—C8—C3	123.7 (6)
H1A—C1—H1B	109.5	C7—C8—H8A	118.2
C2—C1—H1C	109.5	C3—C8—H8A	118.2
H1A—C1—H1C	109.5	C11—C9—C10	109.3 (5)
H1B—C1—H1C	109.5	C11—C9—C12	109.0 (5)
C1—C2—C3	112.4 (6)	C10—C9—C12	110.1 (5)
C1—C2—H2A	109.1	C11—C9—C6	111.7 (5)
C3—C2—H2A	109.1	C10—C9—C6	111.5 (5)
C1—C2—H2B	109.1	C12—C9—C6	105.1 (4)
C3—C2—H2B	109.1	C9—C10—H10A	109.5
H2A—C2—H2B	107.8	C9—C10—H10B	109.5
C8—C3—C4	115.0 (5)	H10A—C10—H10B	109.5
C8—C3—C2	121.2 (6)	C9—C10—H10C	109.5
C4—C3—C2	123.8 (5)	H10A—C10—H10C	109.5
C3—C4—C5	123.2 (5)	H10B—C10—H10C	109.5
C3—C4—Br	120.3 (4)	C9—C11—H11A	109.5
C5—C4—Br	116.5 (5)	C9—C11—H11B	109.5
C6—C5—C4	120.2 (5)	H11A—C11—H11B	109.5
C6—C5—H5A	119.9	C9—C11—H11C	109.5
C4—C5—H5A	119.9	H11A—C11—H11C	109.5
C5—C6—C7	117.5 (5)	H11B—C11—H11C	109.5
C5—C6—C9	122.6 (5)	O2—C12—O1	123.0 (6)
C7—C6—C9	119.9 (5)	O2—C12—C9	123.3 (5)
C8—C7—C6	120.5 (6)	O1—C12—C9	113.7 (5)

C1—C2—C3—C8	−95.0 (8)	C2—C3—C8—C7	178.3 (6)
C1—C2—C3—C4	84.7 (8)	C5—C6—C9—C11	−144.6 (6)
C8—C3—C4—C5	1.5 (9)	C7—C6—C9—C11	36.7 (7)
C2—C3—C4—C5	−178.3 (6)	C5—C6—C9—C10	−22.0 (8)
C8—C3—C4—Br	−178.4 (4)	C7—C6—C9—C10	159.4 (6)
C2—C3—C4—Br	1.9 (8)	C5—C6—C9—C12	97.3 (6)
C3—C4—C5—C6	−0.9 (9)	C7—C6—C9—C12	−81.4 (6)
Br—C4—C5—C6	178.9 (4)	C11—C9—C12—O2	−18.2 (8)
C4—C5—C6—C7	0.2 (8)	C10—C9—C12—O2	−138.1 (6)
C4—C5—C6—C9	−178.5 (5)	C6—C9—C12—O2	101.7 (6)
C5—C6—C7—C8	−0.2 (9)	C11—C9—C12—O1	163.1 (5)
C9—C6—C7—C8	178.5 (6)	C10—C9—C12—O1	43.2 (7)
C6—C7—C8—C3	0.9 (11)	C6—C9—C12—O1	−77.0 (6)
C4—C3—C8—C7	−1.5 (10)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1D···O2ⁱ	0.82	1.88	2.696 (6)	178

Symmetry code: (i) −x, −y, −z.

Experimental details

Crystal data
Chemical formula	C₁₂H₁₅BrO₂
M_r	271.15
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	298
a, b, c (Å)	9.7370 (19), 7.2930 (15), 17.433 (4)
β (°)	90.98 (3)
V (Å³)	1237.8 (4)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	3.30
Crystal size (mm)	0.20 × 0.10 × 0.10

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	ψ scan (North et al., 1968)
T_min, T_max	0.558, 0.734
No. of measured, independent and observed [I > 2σ(I)] reflections	2389, 2246, 1171
R_int	0.051
(sin θ/λ)_max (Å⁻¹)	0.601

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.065, 0.157, 1.00
No. of reflections	2246
No. of parameters	136
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.37, −0.56

Computer programs: CAD-4 Software (Enraf–Nonius, 1985), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1D···O2ⁱ	0.82	1.88	2.696 (6)	178

Symmetry code: (i) −x, −y, −z.

Acknowledgements

The authors thank the Center of Testing and Analysis, Nanjing University, for support.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
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Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Google Scholar
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Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Wiegand, J. M. C., Schafer, C., Palaoro, M., Skranc, W. & Maurer, O. (2007). WO Patent No. 2007096034. Google Scholar