2-(4-Bromo­phen­yl)-2-oxoethyl 4-methyl­benzoate

The title compound, C₁₆H₁₃BrO₃, consists of a toluene ring and a bromo­benzene ring which are linked together by a 2-oxopropyl acetate group. The dihedral angle formed between the toluene and bromo­benzene rings is 80.70 (7)°. In the crystal, inter­molecular C—H...O hydrogen bonds link the mol­ecules into a three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.028
• wR factor = 0.074
• Data-to-parameter ratio = 21.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600         13
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600         11

Alert level G
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT960_ALERT_3_G Number of Intensities with I .LT. - 2*sig(I) ...          1

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   2 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

In organic chemistry, phenacyl benzoate is a derivative of an acid which is formed by the reaction between an acid and a phenacyl bromide. They find applications in the field of synthetic chemistry (Rather & Reid, 1919; Huang et al., 1996; Gandhi et al., 1995) such as in the synthesis of oxazoles, imidazoles, benzoxazepines. They are also useful as photo-removable protecting groups for carboxylic acids in organic synthesis and biochemistry (Ruzicka et al., 2002; Litera et al., 2006; Sheehan & Umezaw, 1973). Keeping this in view, the title compound was synthesized to study its crystal structure.

The title compound, (Fig. 1), consists of a toluene ring (C10–C16) and a bromobenzene ring (C1–C6/Br1) which are linked together by a 2-oxopropyl acetate group (C7–C9/O1–O3). The dihedral angle formed between the toluene and bromobenzene rings is 80.70 (7)%. The bond lengths (Allen et al., 1987) and angles are within normal ranges and are comparable to these closely related structure (Fun et al., 2011).

In the crystal packing (Fig. 2), intermolecular C16—H16A···O2 and C16—H16B···O3 hydrogen bonds (Table 1) link the molecules into a three-dimensional network.

Related literature

For applications of phenacyl benzoate derivatives, see: Rather & Reid (1919); Judefind & Reid (1920); Gandhi et al. (1995); Huang et al. (1996); Sheehan & Umezaw (1973); Ruzicka et al. (2002); Litera et al. (2006). For a related structure, see: Fun et al. (2011). For bond-length data, see: Allen et al. (1987).

S2. Experimental

The mixture of 4-methylbenzoic acid (1.0 g, 0.0073 mol), potassium carbonate (1.10 g, 0.0080 mol) and 2-bromo-1-(4-bromophenyl)ethanone (2.02 g, 0.0073 mol) in dimethylformamide (10 ml) was stirred at room temperature for 2 h. On cooling, the separated yellow needle-shaped crystals of 2-(4-bromophenyl)-2-oxoethyl 4-methylbenzoate were collected by filtration. Compound was recrystallized from ethanol. Yield: 2.22 g, 90.98%. M.p.: 425–426 K (Judefind & Reid, 1920).

S3. Refinement

All the H atoms were positioned geometrically [C–H = 0.9500–0.9900 Å] and were refined using a riding model, with U_iso(H) = 1.2 or 1.5U_iso(C).

Computing details

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures

	Fig. 1. The molecular structure of the title compound, showing 30% probability displacement ellipsoids and the atom-numbering scheme.
	Fig. 2. The crystal packing of the title compound, viewed along a axis. Intermolecular hydrogen bonds linked the molecules into three-dimensional network.

2-(4-Bromophenyl)-2-oxoethyl 4-methylbenzoate

Crystal data

C16H13BrO3	F(000) = 672
Mr = 333.17	Dx = 1.631 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 6134 reflections
a = 5.8368 (2) Å	θ = 2.6–32.4°
b = 8.3438 (3) Å	µ = 3.03 mm^−1
c = 27.9684 (8) Å	T = 100 K
β = 95.177 (1)°	Needle, yellow
V = 1356.54 (8) Å^3	0.50 × 0.14 × 0.12 mm
Z = 4

Data collection

Bruker SMART APEXII CCD area-detector diffractometer	3936 independent reflections
Radiation source: fine-focus sealed tube	3395 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.026
φ and ω scans	θmax = 30.0°, θmin = 1.5°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −8→8
Tmin = 0.311, Tmax = 0.707	k = −11→11
14735 measured reflections	l = −39→39

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.074	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0324P)^2 + 1.2242P] where P = (Fo^2 + 2Fc^2)/3
3936 reflections	(Δ/σ)max = 0.002
182 parameters	Δρmax = 0.45 e Å^−3
0 restraints	Δρmin = −0.42 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
Br1	1.36051 (3)	0.73030 (2)	1.049704 (6)	0.02370 (7)
O1	0.6371 (2)	1.02498 (16)	0.79328 (4)	0.0188 (3)
O2	0.5266 (2)	0.82885 (16)	0.86329 (5)	0.0228 (3)
O3	0.3804 (2)	1.16704 (15)	0.83172 (4)	0.0193 (3)
C1	1.0857 (3)	0.9333 (2)	0.92209 (6)	0.0166 (3)
H1A	1.1334	1.0088	0.8996	0.020*
C2	1.2317 (3)	0.8944 (2)	0.96256 (6)	0.0177 (3)
H2A	1.3795	0.9423	0.9677	0.021*
C3	1.1589 (3)	0.7853 (2)	0.99509 (6)	0.0171 (3)
C4	0.9420 (3)	0.7134 (2)	0.98883 (6)	0.0184 (3)
H4A	0.8935	0.6401	1.0119	0.022*
C5	0.7995 (3)	0.7520 (2)	0.94806 (7)	0.0179 (3)
H5A	0.6523	0.7032	0.9429	0.022*
C6	0.8693 (3)	0.86164 (19)	0.91454 (6)	0.0154 (3)
C7	0.7111 (3)	0.8959 (2)	0.87074 (6)	0.0161 (3)
C8	0.7881 (3)	1.0191 (2)	0.83609 (6)	0.0177 (3)
H8A	0.7936	1.1258	0.8516	0.021*
H8B	0.9453	0.9925	0.8279	0.021*
C9	0.4324 (3)	1.09906 (19)	0.79604 (6)	0.0150 (3)
C10	0.2867 (3)	1.08669 (19)	0.74980 (6)	0.0146 (3)
C11	0.0783 (3)	1.1700 (2)	0.74432 (6)	0.0161 (3)
H11A	0.0369	1.2395	0.7690	0.019*
C12	−0.0687 (3)	1.1510 (2)	0.70261 (6)	0.0173 (3)
H12A	−0.2101	1.2081	0.6991	0.021*
C13	−0.0108 (3)	1.0493 (2)	0.66597 (6)	0.0155 (3)
C14	0.2036 (3)	0.9726 (2)	0.67110 (6)	0.0168 (3)
H14A	0.2490	0.9076	0.6457	0.020*
C15	0.3505 (3)	0.9897 (2)	0.71243 (6)	0.0166 (3)
H15A	0.4943	0.9357	0.7154	0.020*
C16	−0.1776 (3)	1.0169 (2)	0.62159 (6)	0.0178 (3)
H16A	−0.2907	1.1038	0.6176	0.027*
H16B	−0.2572	0.9150	0.6256	0.027*
H16C	−0.0917	1.0111	0.5931	0.027*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.02204 (10)	0.03193 (11)	0.01642 (9)	0.00268 (7)	−0.00216 (6)	0.00657 (7)
O1	0.0149 (6)	0.0279 (6)	0.0133 (6)	0.0042 (5)	−0.0009 (5)	0.0007 (5)
O2	0.0189 (6)	0.0216 (6)	0.0267 (7)	−0.0048 (5)	−0.0049 (5)	0.0034 (5)
O3	0.0223 (6)	0.0201 (6)	0.0151 (6)	0.0030 (5)	0.0003 (5)	−0.0024 (5)
C1	0.0174 (8)	0.0179 (7)	0.0143 (8)	−0.0008 (6)	0.0001 (6)	0.0017 (6)
C2	0.0166 (8)	0.0202 (8)	0.0159 (8)	−0.0012 (6)	0.0000 (6)	−0.0002 (6)
C3	0.0179 (8)	0.0201 (8)	0.0130 (7)	0.0040 (6)	0.0006 (6)	0.0005 (6)
C4	0.0183 (8)	0.0190 (8)	0.0183 (8)	0.0017 (6)	0.0045 (6)	0.0039 (6)
C5	0.0153 (8)	0.0177 (8)	0.0207 (8)	0.0006 (6)	0.0014 (6)	0.0017 (6)
C6	0.0168 (8)	0.0142 (7)	0.0148 (7)	0.0009 (6)	−0.0003 (6)	−0.0008 (6)
C7	0.0166 (8)	0.0152 (7)	0.0160 (8)	0.0020 (6)	−0.0005 (6)	−0.0011 (6)
C8	0.0155 (8)	0.0220 (8)	0.0150 (8)	−0.0003 (6)	−0.0025 (6)	0.0022 (6)
C9	0.0157 (7)	0.0138 (7)	0.0154 (8)	−0.0005 (6)	0.0007 (6)	0.0022 (6)
C10	0.0154 (7)	0.0146 (7)	0.0136 (7)	−0.0004 (6)	0.0012 (6)	0.0011 (6)
C11	0.0168 (8)	0.0177 (7)	0.0139 (7)	0.0011 (6)	0.0014 (6)	−0.0003 (6)
C12	0.0153 (8)	0.0188 (8)	0.0176 (8)	0.0031 (6)	0.0006 (6)	0.0023 (6)
C13	0.0167 (8)	0.0164 (7)	0.0134 (7)	−0.0033 (6)	0.0020 (6)	0.0036 (6)
C14	0.0204 (8)	0.0154 (7)	0.0151 (8)	−0.0001 (6)	0.0036 (6)	−0.0018 (6)
C15	0.0162 (8)	0.0163 (7)	0.0175 (8)	0.0018 (6)	0.0016 (6)	0.0005 (6)
C16	0.0164 (8)	0.0174 (7)	0.0198 (8)	0.0002 (6)	0.0018 (6)	0.0033 (6)

Geometric parameters (Å, º)

Br1—C3	1.8986 (16)	C8—H8A	0.9900
O1—C9	1.354 (2)	C8—H8B	0.9900
O1—C8	1.4222 (19)	C9—C10	1.486 (2)
O2—C7	1.215 (2)	C10—C11	1.397 (2)
O3—C9	1.210 (2)	C10—C15	1.399 (2)
C1—C2	1.393 (2)	C11—C12	1.394 (2)
C1—C6	1.396 (2)	C11—H11A	0.9500
C1—H1A	0.9500	C12—C13	1.395 (2)
C2—C3	1.381 (2)	C12—H12A	0.9500
C2—H2A	0.9500	C13—C14	1.402 (2)
C3—C4	1.397 (3)	C13—C16	1.531 (2)
C4—C5	1.387 (2)	C14—C15	1.383 (2)
C4—H4A	0.9500	C14—H14A	0.9500
C5—C6	1.397 (2)	C15—H15A	0.9500
C5—H5A	0.9500	C16—H16A	0.9800
C6—C7	1.494 (2)	C16—H16B	0.9800
C7—C8	1.509 (2)	C16—H16C	0.9800
C9—O1—C8	116.81 (14)	O3—C9—O1	123.32 (15)
C2—C1—C6	120.12 (16)	O3—C9—C10	125.74 (16)
C2—C1—H1A	119.9	O1—C9—C10	110.94 (14)
C6—C1—H1A	119.9	C11—C10—C15	119.59 (15)
C3—C2—C1	119.15 (16)	C11—C10—C9	119.01 (15)
C3—C2—H2A	120.4	C15—C10—C9	121.37 (15)
C1—C2—H2A	120.4	C12—C11—C10	119.97 (16)
C2—C3—C4	121.99 (16)	C12—C11—H11A	120.0
C2—C3—Br1	118.94 (13)	C10—C11—H11A	120.0
C4—C3—Br1	119.08 (13)	C11—C12—C13	120.80 (16)
C5—C4—C3	118.20 (16)	C11—C12—H12A	119.6
C5—C4—H4A	120.9	C13—C12—H12A	119.6
C3—C4—H4A	120.9	C12—C13—C14	118.42 (15)
C4—C5—C6	120.94 (16)	C12—C13—C16	121.62 (15)
C4—C5—H5A	119.5	C14—C13—C16	119.94 (15)
C6—C5—H5A	119.5	C15—C14—C13	121.25 (16)
C1—C6—C5	119.59 (15)	C15—C14—H14A	119.4
C1—C6—C7	121.73 (15)	C13—C14—H14A	119.4
C5—C6—C7	118.66 (15)	C14—C15—C10	119.84 (16)
O2—C7—C6	121.70 (16)	C14—C15—H15A	120.1
O2—C7—C8	120.97 (15)	C10—C15—H15A	120.1
C6—C7—C8	117.33 (14)	C13—C16—H16A	109.5
O1—C8—C7	111.48 (14)	C13—C16—H16B	109.5
O1—C8—H8A	109.3	H16A—C16—H16B	109.5
C7—C8—H8A	109.3	C13—C16—H16C	109.5
O1—C8—H8B	109.3	H16A—C16—H16C	109.5
C7—C8—H8B	109.3	H16B—C16—H16C	109.5
H8A—C8—H8B	108.0
C6—C1—C2—C3	−0.5 (3)	C8—O1—C9—O3	4.6 (2)
C1—C2—C3—C4	−0.5 (3)	C8—O1—C9—C10	−176.21 (14)
C1—C2—C3—Br1	179.08 (13)	O3—C9—C10—C11	5.6 (3)
C2—C3—C4—C5	1.2 (3)	O1—C9—C10—C11	−173.61 (15)
Br1—C3—C4—C5	−178.36 (13)	O3—C9—C10—C15	−172.35 (17)
C3—C4—C5—C6	−1.0 (3)	O1—C9—C10—C15	8.5 (2)
C2—C1—C6—C5	0.7 (3)	C15—C10—C11—C12	2.6 (3)
C2—C1—C6—C7	−177.82 (16)	C9—C10—C11—C12	−175.38 (16)
C4—C5—C6—C1	0.1 (3)	C10—C11—C12—C13	0.1 (3)
C4—C5—C6—C7	178.61 (16)	C11—C12—C13—C14	−3.0 (3)
C1—C6—C7—O2	177.11 (17)	C11—C12—C13—C16	175.28 (16)
C5—C6—C7—O2	−1.4 (3)	C12—C13—C14—C15	3.4 (3)
C1—C6—C7—C8	−3.6 (2)	C16—C13—C14—C15	−174.92 (16)
C5—C6—C7—C8	177.94 (16)	C13—C14—C15—C10	−0.8 (3)
C9—O1—C8—C7	75.60 (19)	C11—C10—C15—C14	−2.2 (3)
O2—C7—C8—O1	−8.3 (2)	C9—C10—C15—C14	175.70 (16)
C6—C7—C8—O1	172.36 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C16—H16A···O2^i	0.98	2.42	3.355 (2)	160
C16—H16B···O3^ii	0.98	2.53	3.451 (2)	157

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