Methyl 3,5-dibromo-4-methyl­benzoate

Saeed, A.; Rafique, H.; Simpson, J.; Ashraf, Z.

doi:10.1107/S1600536810011062

organic compounds

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ISSN: 2056-9890

Volume 66| Part 4| April 2010| Pages o982-o983

doi:10.1107/S1600536810011062

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Methyl 3,5-dibromo-4-methylbenzoate

Aamer Saeed,^a ^* Hummera Rafique,^a Jim Simpson ^b and Zaman Ashraf ^c

^aDepartment of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan, ^bDepartment of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand, and ^cRiphah Institute of Pharmaceutical Sciences, Islamabad, Pakistan
^*Correspondence e-mail: aamersaeed@yahoo.com

(Received 18 March 2010; accepted 24 March 2010; online 31 March 2010)

In the title compound, C₉H₈Br₂O₂, the molecule is essentially planar with an r.m.s. deviation of 0.0652 Å from the mean plane through all non-H atoms and a dihedral angle of 7.1 (2)° between the benzene ring plane and the carboxylate substituent. In the crystal structure, weak C—H⋯Br hydrogen bonds and weak intermolecular O⋯Br contacts [3.095 (2) Å], link adjacent molecules into layers parallel to (102). Additional weak intermolecular C—H⋯O hydrogen bond interactions stack the layers above and below the molecular plane and down the a axis.

Related literature

For use of the title compound in the synthesis of natural products, see: Gray & Whalley (1971 ); Saeed & Rama (1994 ); Harris & Mantle (2001 ); Simpson (1978 ). For related structures, see: Moorthy et al. (2002 ); Fan et al. (2005 ). For intermolecular O⋯Br contacts, see: Choi et al. (2010a ,b ); Politzer et al. (2007 ). For bond-length data, see: Allen et al. (1987 ).

Experimental

Crystal data

C₉H₈Br₂O₂
M_r = 307.97
Orthorhombic, P 2₁ 2₁ 2₁
a = 3.9716 (2) Å
b = 14.2359 (7) Å
c = 17.2893 (8) Å
V = 977.52 (8) Å³
Z = 4
Mo Kα radiation
μ = 8.26 mm⁻¹
T = 89 K
0.64 × 0.14 × 0.08 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2006 ) T_min = 0.295, T_max = 1.000
17658 measured reflections
3471 independent reflections
2922 reflections with I > 2σ(I)
R_int = 0.061

Refinement

R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.065
S = 1.09
3471 reflections
120 parameters
H-atom parameters constrained
Δρ_max = 1.15 e Å⁻³
Δρ_min = −1.09 e Å⁻³
Absolute structure: Flack (1983 ), 1659 Friedel pairs
Flack parameter: 0.039 (14)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8C⋯O2ⁱ	0.98	2.70	3.546 (5)	145
C6—H6⋯Br2ⁱⁱ	0.95	2.93	3.838 (3)	159
C8—H8A⋯O1ⁱⁱⁱ	0.98	2.69	3.647 (4)	167
Symmetry codes: (i) x-1, y, z; (ii) $[-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iii) $[x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+1]$ .

Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 and SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and TITAN2000 (Hunter & Simpson, 1999 ); molecular graphics: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2008 ); software used to prepare material for publication: SHELXL97, enCIFer (Allen et al., 2004 ), PLATON (Spek, 2009 ) and publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810011062/jj2027sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810011062/jj2027Isup2.hkl

checkCIF report

Comment top

The title ester, (I), Fig. 1, is an important intermediate towards synthesis of 3,5-dimethoxyphenylacetic acid, a key intermediate in the synthesis of a variety of natural products. These include the sclerotiorin group of fungal metabolites (Gray & Whalley, 1971), isochromans related to sclerotiorin pigments (Saeed & Rama, 1994) and isocoumarins like 7-methylmellein (Harris & Mantle, 2001) and stellatin (Simpson, 1978). C₉H₈O₂Br₂, (I), was prepared by bromination of methyl 4-methylbenzoate in presence of anhydrous aluminum chloride using an excess of calalyst and no solvent.

The molecule is essentially flat with an rms deviation of 0.0652 Å from the mean plane through all non-hydrogen atoms. The dihedral angle between the C1···C6 ring plane and that of the C7/O1/O2/C8 carboxylate unit is 7.1 (2)°. Bond distances in the molecule are normal (Allen et al., 1987) and comparable to those in related structures (Moorthy et al., 2002; Fan et al., 2005).

In the crystal structure weak intermolecular C6—H6···Br2 hydrogen bonds and weak O1···Br2 contacts at 3.095 (2)Å (Choi et al., 2010a,b; Politzer et al., 2007) link adjacent molecules into layers parallel to the (102) plane. Additional weak intermolecular C8–H8A···O1 and C8–H8C···O2 hydrogen bond interactions involving the carboxylate methyl group stack these layers above and below the molecular plane and down the a axis, Table 1, Fig. 2.

Related literature top

For use of the title compound in the synthesis of natural products, see: Gray & Whalley (1971); Saeed & Rama (1994); Harris & Mantle (2001); Simpson (1978). For related structures, see: Moorthy et al. (2002); Fan et al. (2005). For intermolecular O···Br contacts, see: Choi et al. (2010a,b); Politzer et al. (2007). For bond-length data, see: Allen et al. (1987).

Experimental top

Anhydrous aluminum chloride (1.60 mmol) was added portionwise to stirred methyl 4-methylbenzoate (0.6 mmol) at 0°C under a nitrogen atmosphere. Bromine was added over 45 min. and the mixture was further stirred for 30 min at room temperature and at 80 °C for 1 h. The mixture was cooled to room temperature, treated with cold methanol (100 ml) and then stirred overnight. The crude product was filtered and washed with methanol at 30°C then recrystallized from methanol at 10°C to to afford the title compound (86%) as colourless crystals: Anal. calcd. for C₉H₈Br₂O₂: C, 35.10; H, 2.62; found: C, 35.23; H, 2.67 %

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 and SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and TITAN2000 (Hunter & Simpson, 1999); molecular graphics: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), enCIFer (Allen et al., 2004), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Figures top

	Fig. 1. The structure of (I) with displacement ellipsoids for the non-hydrogen atoms drawn at the 50% probability level.
	Fig. 2. Crystal packing for (I) viewed down the a axis with weak hydrogen bonds and weak O···Br contacts drawn as dashed lines.

Methyl 3,5-dibromo-4-methylbenzoate top

Crystal data top

C₉H₈Br₂O₂	F(000) = 592
M_r = 307.97	D_x = 2.093 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 4848 reflections
a = 3.9716 (2) Å	θ = 2.8–30.4°
b = 14.2359 (7) Å	µ = 8.26 mm⁻¹
c = 17.2893 (8) Å	T = 89 K
V = 977.52 (8) Å³	Rectangular plate, colourless
Z = 4	0.64 × 0.14 × 0.08 mm

Data collection top

Bruker APEXII CCD diffractometer	3471 independent reflections
Radiation source: fine-focus sealed tube	2922 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.061
ω scans	θ_max = 33.3°, θ_min = 3.7°
Absorption correction: multi-scan (SADABS; Bruker, 2006)	h = −6→4
T_min = 0.295, T_max = 1.000	k = −21→21
17658 measured reflections	l = −25→25

Refinement top

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)] = 0.033	H-atom parameters constrained
wR(F²) = 0.065	w = 1/[σ²(F_o²) + 0.5972P] where P = (F_o² + 2F_c²)/3
S = 1.09	(Δ/σ)_max = 0.001
3471 reflections	Δρ_max = 1.15 e Å⁻³
120 parameters	Δρ_min = −1.09 e Å⁻³
0 restraints	Absolute structure: Flack (1983), 1659 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.039 (14)

Crystal data top

C₉H₈Br₂O₂	V = 977.52 (8) Å³
M_r = 307.97	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 3.9716 (2) Å	µ = 8.26 mm⁻¹
b = 14.2359 (7) Å	T = 89 K
c = 17.2893 (8) Å	0.64 × 0.14 × 0.08 mm

Data collection top

Bruker APEXII CCD diffractometer	3471 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2006)	2922 reflections with I > 2σ(I)
T_min = 0.295, T_max = 1.000	R_int = 0.061
17658 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	H-atom parameters constrained
wR(F²) = 0.065	Δρ_max = 1.15 e Å⁻³
S = 1.09	Δρ_min = −1.09 e Å⁻³
3471 reflections	Absolute structure: Flack (1983), 1659 Friedel pairs
120 parameters	Absolute structure parameter: 0.039 (14)
0 restraints

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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
Br1	0.86943 (10)	0.87630 (2)	0.134557 (17)	0.01774 (7)
C1	0.7685 (7)	0.7603 (2)	0.18453 (18)	0.0116 (6)
C2	0.8609 (8)	0.67455 (19)	0.15060 (16)	0.0119 (5)
C21	1.0349 (8)	0.6680 (2)	0.07366 (19)	0.0172 (7)
H21A	1.2073	0.6188	0.0757	0.026*
H21B	1.1411	0.7283	0.0615	0.026*
H21C	0.8697	0.6525	0.0335	0.026*
C3	0.7704 (8)	0.5947 (2)	0.19236 (18)	0.0120 (6)
Br2	0.86513 (9)	0.47350 (2)	0.151431 (17)	0.01548 (7)
C4	0.6050 (9)	0.59686 (19)	0.26311 (17)	0.0128 (5)
H4	0.5508	0.5404	0.2897	0.015*
C5	0.5202 (7)	0.6844 (2)	0.29418 (19)	0.0122 (6)
C6	0.6011 (9)	0.7667 (2)	0.25473 (17)	0.0138 (6)
H6	0.5426	0.8262	0.2756	0.017*
C7	0.3351 (8)	0.69264 (19)	0.36902 (17)	0.0133 (5)
O1	0.2258 (6)	0.76517 (15)	0.39530 (14)	0.0181 (5)
O2	0.3030 (6)	0.60888 (15)	0.40440 (12)	0.0163 (5)
C8	0.1345 (11)	0.6119 (2)	0.47902 (17)	0.0214 (6)
H8A	0.2618	0.6524	0.5144	0.032*
H8B	0.1215	0.5483	0.5005	0.032*
H8C	−0.0933	0.6371	0.4725	0.032*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.02028 (15)	0.01578 (13)	0.01716 (15)	−0.00211 (15)	0.00154 (16)	0.00416 (11)
C1	0.0112 (13)	0.0118 (13)	0.0118 (14)	−0.0026 (10)	−0.0006 (11)	0.0039 (11)
C2	0.0084 (10)	0.0148 (11)	0.0126 (13)	−0.0006 (13)	−0.0016 (14)	0.0007 (10)
C21	0.0153 (14)	0.0231 (16)	0.0131 (16)	0.0021 (13)	0.0022 (12)	0.0006 (12)
C3	0.0122 (14)	0.0129 (13)	0.0109 (14)	−0.0004 (11)	−0.0019 (11)	−0.0009 (10)
Br2	0.01713 (14)	0.01478 (12)	0.01454 (14)	0.00131 (14)	0.00229 (15)	−0.00278 (10)
C4	0.0103 (13)	0.0151 (12)	0.0131 (13)	−0.0003 (13)	−0.0004 (13)	−0.0003 (10)
C5	0.0090 (12)	0.0176 (14)	0.0099 (14)	−0.0004 (11)	−0.0032 (11)	−0.0003 (12)
C6	0.0122 (14)	0.0139 (13)	0.0152 (13)	−0.0009 (13)	−0.0006 (13)	0.0002 (10)
C7	0.0139 (14)	0.0161 (13)	0.0099 (12)	−0.0001 (11)	−0.0028 (12)	−0.0013 (10)
O1	0.0206 (12)	0.0177 (11)	0.0160 (11)	0.0043 (9)	0.0027 (9)	−0.0009 (9)
O2	0.0208 (13)	0.0181 (10)	0.0098 (10)	−0.0014 (9)	0.0048 (9)	0.0003 (8)
C8	0.0235 (16)	0.0295 (16)	0.0113 (14)	−0.0020 (18)	0.0063 (16)	0.0020 (12)

Geometric parameters (Å, º) top

Br1—C1	1.907 (3)	C4—H4	0.9500
C1—C6	1.387 (4)	C5—C6	1.393 (4)
C1—C2	1.403 (4)	C5—C7	1.493 (4)
C2—C3	1.394 (4)	C6—H6	0.9500
C2—C21	1.502 (4)	C7—O1	1.209 (3)
C21—H21A	0.9800	C7—O2	1.346 (3)
C21—H21B	0.9800	O1—Br2ⁱ	3.095 (2)
C21—H21C	0.9800	O2—C8	1.454 (4)
C3—C4	1.389 (4)	C8—H8A	0.9800
C3—Br2	1.902 (3)	C8—H8B	0.9800
C4—C5	1.398 (4)	C8—H8C	0.9800

C6—C1—C2	123.3 (3)	C6—C5—C4	120.4 (3)
C6—C1—Br1	116.1 (2)	C6—C5—C7	118.2 (3)
C2—C1—Br1	120.6 (2)	C4—C5—C7	121.4 (3)
C3—C2—C1	115.2 (3)	C1—C6—C5	119.0 (3)
C3—C2—C21	121.8 (3)	C1—C6—H6	120.5
C1—C2—C21	123.0 (3)	C5—C6—H6	120.5
C2—C21—H21A	109.5	O1—C7—O2	123.5 (3)
C2—C21—H21B	109.5	O1—C7—C5	124.7 (3)
H21A—C21—H21B	109.5	O2—C7—C5	111.8 (2)
C2—C21—H21C	109.5	C7—O1—Br2ⁱ	139.7 (2)
H21A—C21—H21C	109.5	C7—O2—C8	114.9 (2)
H21B—C21—H21C	109.5	O2—C8—H8A	109.5
C4—C3—C2	124.0 (3)	O2—C8—H8B	109.5
C4—C3—Br2	116.2 (2)	H8A—C8—H8B	109.5
C2—C3—Br2	119.7 (2)	O2—C8—H8C	109.5
C3—C4—C5	118.2 (3)	H8A—C8—H8C	109.5
C3—C4—H4	120.9	H8B—C8—H8C	109.5
C5—C4—H4	120.9

C6—C1—C2—C3	0.4 (4)	C2—C1—C6—C5	0.2 (5)
Br1—C1—C2—C3	−179.4 (2)	Br1—C1—C6—C5	−180.0 (2)
C6—C1—C2—C21	178.5 (3)	C4—C5—C6—C1	−0.4 (4)
Br1—C1—C2—C21	−1.3 (4)	C7—C5—C6—C1	−179.0 (3)
C1—C2—C3—C4	−0.9 (5)	C6—C5—C7—O1	6.2 (5)
C21—C2—C3—C4	−179.0 (3)	C4—C5—C7—O1	−172.5 (3)
C1—C2—C3—Br2	177.7 (2)	C6—C5—C7—O2	−173.9 (3)
C21—C2—C3—Br2	−0.4 (4)	C4—C5—C7—O2	7.5 (4)
C2—C3—C4—C5	0.7 (5)	O2—C7—O1—Br2ⁱ	−172.96 (18)
Br2—C3—C4—C5	−177.9 (2)	C5—C7—O1—Br2ⁱ	7.0 (5)
C3—C4—C5—C6	−0.1 (4)	O1—C7—O2—C8	−2.0 (4)
C3—C4—C5—C7	178.6 (3)	C5—C7—O2—C8	178.1 (3)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8C···O2ⁱⁱ	0.98	2.70	3.546 (5)	145
C6—H6···Br2ⁱ	0.95	2.93	3.838 (3)	159
C8—H8A···O1ⁱⁱⁱ	0.98	2.69	3.647 (4)	167

Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) x−1, y, z; (iii) x+1/2, −y+3/2, −z+1.

Experimental details

Crystal data
Chemical formula	C₉H₈Br₂O₂
M_r	307.97
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	89
a, b, c (Å)	3.9716 (2), 14.2359 (7), 17.2893 (8)
V (Å³)	977.52 (8)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	8.26
Crystal size (mm)	0.64 × 0.14 × 0.08

Data collection
Diffractometer	Bruker APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2006)
T_min, T_max	0.295, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	17658, 3471, 2922
R_int	0.061
(sin θ/λ)_max (Å⁻¹)	0.773

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.065, 1.09
No. of reflections	3471
No. of parameters	120
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	1.15, −1.09
Absolute structure	Flack (1983), 1659 Friedel pairs
Absolute structure parameter	0.039 (14)

Computer programs: APEX2 (Bruker, 2006), APEX2 and SAINT (Bruker, 2006), SAINT (Bruker, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and TITAN2000 (Hunter & Simpson, 1999), SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2008), SHELXL97 (Sheldrick, 2008), enCIFer (Allen et al., 2004), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8C···O2ⁱ	0.98	2.70	3.546 (5)	144.6
C6—H6···Br2ⁱⁱ	0.95	2.93	3.838 (3)	159.3
C8—H8A···O1ⁱⁱⁱ	0.98	2.69	3.647 (4)	166.7

Symmetry codes: (i) x−1, y, z; (ii) −x+1, y+1/2, −z+1/2; (iii) x+1/2, −y+3/2, −z+1.

Acknowledgements

The authors gratefully acknowledge a research grant from the Higher Education Commission of Pakistan, project No. 20-Miscel/R&D/00/3834. We also thank the University of Otago for purchase of the diffractometer.

References

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