2-(4-Methyl­phen­yl)-2-oxoethyl 3-bromo­benzoate

Imtiaz Khan; Aliya Ibrar; Artur Korzański; Maciej Kubicki

doi:10.1107/S1600536812046995

. 2012 Nov 28;68(Pt 12):o3465. doi: 10.1107/S1600536812046995

2-(4-Methylphenyl)-2-oxoethyl 3-bromobenzoate

Imtiaz Khan ^a,^*, Aliya Ibrar ^a, Artur Korzański ^b, Maciej Kubicki ^b

PMCID: PMC3589039 PMID: 23476275

Abstract

The molecule of the title compound, C₁₆H₁₃BrO₃, is built of two approximately planar fragments, viz. 3-bromobenzoate [maximum deviation = 0.055 (2) Å and 2-oxo-2-p-tolylethyl [maximum deviation = 0.042 (2) Å], inclined by 46.51 (7)°. In the crystal, weak C—H⋯O hydrogen bonds and Br⋯Br contacts [3.6491 (7) Å] connect the molecules into infinite layers parallel to (-221).

Related literature

For the structures of similar compounds, see: Fun, Arshad et al. (2011 ▶); Fun, Loh et al. (2011 ▶); Fun, Ooi et al. (2011 ▶); Fun, Shahani et al. (2011 ▶).

Experimental

Crystal data

C₁₆H₁₃BrO₃
M _r = 333.17
Triclinic,
a = 4.7977 (3) Å
b = 10.9951 (7) Å
c = 14.1645 (8) Å
α = 74.829 (5)°
β = 87.758 (5)°
γ = 79.327 (5)°
V = 708.64 (7) Å³
Z = 2
Mo Kα radiation
μ = 2.90 mm⁻¹
T = 295 K
0.25 × 0.2 × 0.08 mm

Data collection

Agilent Xcalibur Eos diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010 ▶) T _min = 0.335, T _max = 1.000
7924 measured reflections
2501 independent reflections
1768 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.038
wR(F ²) = 0.106
S = 1.05
2501 reflections
192 parameters
H-atom parameters constrained
Δρ_max = 0.44 e Å⁻³
Δρ_min = −0.42 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶) and Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Click here for additional data file.^{(21.6KB, cif)}

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812046995/ng5304sup1.cif

e-68-o3465-sup1.cif^{(21.6KB, cif)}

Click here for additional data file.^{(120.3KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812046995/ng5304Isup2.hkl

e-68-o3465-Isup2.hkl^{(120.3KB, hkl)}

Click here for additional data file.^{(5.1KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536812046995/ng5304Isup3.cml

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
C5—H5⋯O10ⁱ	0.93	2.44	3.198 (4)	139
C9—H92⋯O7ⁱⁱ	0.97	2.56	3.406 (4)	146

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Symmetry codes: (i) Inline graphic ; (ii) .

supplementary crystallographic information

Comment

Keto esters, an important class of versatile intermediates, are extensively used in agrochemical, pharmaceutical, and dyestuff industries. They are also useful organic building blocks for the synthesis of complex natural products and are frequently employed synthons in organic synthesis, especially in heterocyclic synthesis. Prompted by literature findings, we herein report the synthesis of 2-(4-methylphenyl)-2-oxoethyl 3-bromobenzoate which can be used as an effective synthon in heterocyclic chemistry. The formation of keto ester (1) was confirmed by the changes in the spectral properties such as IR absorptions, ¹H and ¹³C NMR signals for dominant functional groups. The conformation of molecule (1) can be described by the dihedral angle between two approximately planar fragments: 3-bromobenzoate (maximum deviation from the least-squares plane is 0.055 (2) Å) and 2-oxo-2-p-tolylethyl (0.042 (2) Å). In the crystal, this angle is 46.51 (7) ° (Fig. 1). In similarly substituted (para-meta) analogues, this angle was much smaller: in 2-(4-fluorophenyl)-2-oxoethyl 3-(trifluoromethyl)benzoate (Fun, Arshad et al., 2011) this angle is 20.34 (9)°, in 2-(4-chlorophenyl)-2-oxoethyl 3-(trifluoromethyl)benzoate (Fun, Loh et al., 2011) - 15.50 (8)°; on the other hand, this angle was larger in some other similar compounds: 66.66 (8)° in 2-(4-bromophenyl)-2-oxoethyl 2-methylbenzoate (Fun, Ooi et al., 2011) and 80.70 (7)° in 2-(4-bromophenyl)-2-oxoethyl 4-methylbenzoate (Fun, Shahani et al., 2011).

Weak but directional C—H···O hydrogen bonds and C—Br···Br(-1 - x,1 - y,-z) halogen interactions (Br···Br 3.6491 (7) Å, C—Br···Br 164.37 (10) °) connect molecules into layers approximately parallel to (-221) plane (Fig. 2); these planes are interacting with one another by means of weak C—H···O contacts and van der Waals interactions.

Experimental

2-(4-Methylphenyl)-2-oxoethyl 3-bromobenzoate (1) was synthesized by treating 3-bromobenzoic acid (0.01 mol) with the solution of 2-bromo-1-p-tolylethanone (0.01 mol) in N,N-dimethylformamide (DMF) using triethylamine (TEA) as a catalyst at room temperature for 2 h. Yield: 87%; m.p 96–97°C; R_f: 0.27 (n-hexane: ethyl acetate, 9: 1); IR (neat, cm^-1): 3034 (C_sp₂-H), 2924, 2853 (C_sp₃-H), 1728 (C=O_ester), 1685 (C=O_keto), 1585, 1561 (C=C), 1230 (C—O); ¹H NMR (300 MHz, CDCl₃): δ 8.08–8.04 (m, 1H, Ar—H), 7.88 (d, 2H, J = 8.4 Hz, Ar—H), 7.72–7.68 (m, 1H, Ar—H), 7.45–7.36 (m, 2H, Ar—H), 7.35–7.28 (m, 2H, Ar—H), 5.59 (s, 2H, OCH₂), 2.44 (s, 3H, CH₃); ¹³C NMR (75 MHz, CDCl₃): δ 191.33, 165.44, 145.06, 134.42, 133.02, 132.04, 131.61, 131.21, 129.64, 127.94, 127.30, 122.07, 66.65, 21.85.

Crystals were obtained by recrystallization from ethyl acetate.