1-Methyl­ethyl 2-[(1-bromo-2-naphthyl)­oxy]­ethano­ate

Molecules of the title compound, C₁₅H₁₅BrO₃, form C—H...π interactions leading to an infinite chain parallel to the [010] direction.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.042
• wR factor = 0.112
• Data-to-parameter ratio = 16.0

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level A:



TYPE_089  Alert A _refine_ls_abs_structure_Flack is not of type numb.


 Alert Level C:



ABSTM_02  Alert C The ratio of expected to reported Tmax/Tmin(RR) is > 1.10
          Tmin and Tmax reported:      0.633     0.633
          Tmin and Tmax expected:      0.754     0.942
          RR =      1.249
          Please check that your absorption correction is appropriate.

General Notes



ABSTM_02  When printed, the submitted absorption T values will be replaced
          by the scaled T values. Since the ratio of scaled T's is
          identical to the ratio of reported T values, the scaling does
          not imply a change to the absorption corrections used in the
          study.
          Ratio of Tmax expected/reported      1.487
          Tmax scaled      0.942 Tmin scaled      0.942

REFLT_03
         From the CIF: _diffrn_reflns_theta_max           27.45
         From the CIF: _reflns_number_total               2792
         Count of symmetry unique reflns         1750
         Completeness (_total/calc)            159.54%
         TEST3: Check Friedels for noncentro structure
         Estimate of Friedel pairs measured      1042
         Fraction of Friedel pairs measured     0.595
         Are heavy atom types Z>Si present          yes
          Please check that the estimate of the number of Friedel pairs is
          correct. If it is not, please give the correct count in the
          _publ_section_exptl_refinement section of the submitted CIF.


 1 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

---

S1. Comment

The title compound, (1), was obtained by the reaction sequence shown in the reaction scheme below. Of particular interest in this scheme were the products of reaction of (2) with N-bromosuccinimide and the competition between bromination of the aromatic ring and the methylene group, α to the carbonyl group. NMR spectroscopy of the final reaction mixture clearly showed that reaction occurred completely in the aromatic ring: no indications for 2-bromo-2-(2-naphthyloxy)ethanoic acid were found.

The asymmetric unit of (1) is shown in Fig. 1 with the numbering scheme; intramolecular C—H···Br are present (C5—H5···Br1, Table 1) although not shown in this diagram.

Molecules of (1) are linked by C—H···π interactions, viz. C4—H4···π. The C1–C6 ring is the acceptor at (2 - x, -1/2 + y, -z), with a C4–centroid distance of 4.146 (7) Å. These are represented in Fig. 2, which shows the zigzag of the resultant chain parallel to the (010) direction (Spek 2001).

S2. Experimental

A solution of 2-naphthyloxyethanoic acid (5.06 g, 0.025 mol), prepared according to a published procedure (Howie et al., 2000), and thionyl chloride (7.5 ml, 0.1 mol) in CHCl₃ (10 ml) was refluxed for 1.5 h and cooled. A mixture of N-bromosuccinimide (4.45 g, 0.025 mol) and aqueous HBr (48%, 2 drops) in CH₂Cl₂ (10 ml) was added, the mixture refluxed for 2 h, cooled, poured onto cold 2-propanol (50 ml) with stirring and left for 2 h. The solution was rotary evaporated to leave a colourless residue, which was separated by chromatography on silica. 1-Methylethyl 2-[(1-bromo-2-naphthyl)oxy]ethanoate was recrystallized from 2-propanol; 2.2 g, m.p. 331–332 K. Crystals for the X-ray study were grown by slow evaporation of a 2-propanol solution. 1H NMR (400 MHz, CDCl₃, p.p.m.): d 1.23 (d, 6H, J = 6.1 Hz, Me), 4.76 (s, 2H, CH₂), 5.11 (sept, J = 6.1 Hz, CH), 7.14 (d, 1H, J = 9.2hz), 7.39 (ddd, 1H, J = 1.0, 6.8, ca 8 Hz), 7.54 (ddd, 1H, J = 1.4, 6.8, 8.6 Hz), 7.65 (d, 2H, J = 8.6 Hz), 8.11 (dd, 1H, J = 1.0, 8.6 Hz). IR (KBr, cm^-1): 2980, 1736, 1624, 1597, 1504, 1464, 1445, 1374, 1383, 1287, 1209, 1178, 1096, 936, 906, 804, 765, 744,709, 641, 596, 518, 414.

S3. Refinement

H atoms were placed in geometrical positions and refined using a riding model.

Computing details

Data collection: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); cell refinement: DENZO and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEX in OSCAIL (McArdle, 1994, 2000) and ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: CIFTAB (Sheldrick, 1997).

Figures

	Fig. 1. Asymmetric unit of the title compound with the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probablity level.
	Fig. 2. Molecules of title compound related by (2 - x, y - 1/2, -z), illustrating C—H···π intermolecular interactions. The unit cell is shown, normal to (001).

1-Methylethyl 2-[(1-bromo-2-naphthalenyl)oxy]ethanoate

Crystal data

C15H15BrO3	F(000) = 328
Mr = 323.18	Dx = 1.573 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
a = 10.3369 (4) Å	Cell parameters from 4552 reflections
b = 4.7557 (2) Å	θ = 1.0–27.5°
c = 14.2208 (7) Å	µ = 3.01 mm^−1
β = 102.4951 (18)°	T = 120 K
V = 682.52 (5) Å^3	Plate, colourless
Z = 2	0.35 × 0.08 × 0.02 mm

Data collection

Enraf Nonius KappaCCD diffractometer	2792 independent reflections
Radiation source: fine-focus sealed tube	2507 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.052
ϕ–ω scans	θmax = 27.5°, θmin = 1.5°
Absorption correction: empirical (using intensity measurements) (SORTAV; Blessing, 1995, 1997)	h = −13→13
Tmin = 0.633, Tmax = 0.633	k = −6→5
4741 measured reflections	l = −16→18

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.042	H-atom parameters constrained
wR(F^2) = 0.112	w = 1/[σ^2(Fo^2) + (0.0509P)^2 + 0.545P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
2792 reflections	Δρmax = 0.79 e Å^−3
174 parameters	Δρmin = −0.96 e Å^−3
1 restraint	Absolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.015 (16), 1058 Friedel pairs

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	0.88045 (4)	0.46057 (13)	0.29285 (3)	0.02619 (15)
C1	0.6839 (4)	0.9920 (14)	0.0722 (3)	0.0231 (11)
C2	0.6901 (5)	1.0579 (11)	−0.0237 (4)	0.0299 (12)
H2	0.6318	1.1956	−0.0579	0.036*
C3	0.7779 (5)	0.9277 (16)	−0.0677 (3)	0.0326 (13)
H3	0.7810	0.9748	−0.1321	0.039*
C4	0.8640 (6)	0.7234 (12)	−0.0176 (4)	0.0314 (12)
H4	0.9241	0.6309	−0.0492	0.038*
C5	0.8636 (5)	0.6537 (11)	0.0763 (4)	0.0246 (10)
H5	0.9242	0.5179	0.1093	0.029*
C6	0.7714 (5)	0.7869 (10)	0.1238 (3)	0.0214 (10)
C7	0.7635 (5)	0.7257 (10)	0.2203 (3)	0.0217 (9)
C8	0.6723 (5)	0.8543 (10)	0.2632 (3)	0.0214 (10)
C9	0.5840 (5)	1.0563 (11)	0.2109 (4)	0.0265 (11)
H9	0.5199	1.1446	0.2398	0.032*
C10	0.5916 (5)	1.1235 (11)	0.1188 (4)	0.0267 (11)
H10	0.5334	1.2621	0.0850	0.032*
O1	0.6745 (3)	0.7845 (8)	0.3571 (2)	0.0265 (8)
C11	0.5798 (4)	0.9111 (11)	0.4034 (3)	0.0249 (12)
H11A	0.5779	1.1165	0.3919	0.030*
H11B	0.6068	0.8793	0.4737	0.030*
C12	0.4420 (5)	0.7905 (10)	0.3663 (3)	0.0241 (10)
O2	0.3540 (3)	0.9384 (11)	0.4023 (2)	0.0237 (7)
O3	0.4171 (4)	0.5876 (9)	0.3152 (3)	0.0351 (9)
C13	0.2134 (5)	0.8627 (11)	0.3683 (3)	0.0257 (11)
H13	0.2043	0.6535	0.3641	0.031*
C14	0.1424 (4)	0.974 (2)	0.4428 (3)	0.0339 (11)
H14A	0.1766	0.8804	0.5045	0.051*
H14B	0.0472	0.9375	0.4219	0.051*
H14C	0.1574	1.1773	0.4503	0.051*
C15	0.1626 (5)	0.9914 (16)	0.2690 (3)	0.0306 (12)
H15A	0.1718	1.1964	0.2733	0.046*
H15B	0.0690	0.9423	0.2458	0.046*
H15C	0.2142	0.9184	0.2242	0.046*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0219 (2)	0.0277 (2)	0.0278 (2)	0.0042 (3)	0.00291 (15)	0.0021 (3)
C1	0.0177 (19)	0.026 (3)	0.0236 (19)	−0.002 (2)	0.0009 (15)	0.001 (3)
C2	0.029 (3)	0.027 (3)	0.030 (3)	−0.009 (2)	−0.001 (2)	0.003 (2)
C3	0.041 (3)	0.033 (4)	0.024 (2)	−0.009 (3)	0.0070 (19)	0.003 (3)
C4	0.037 (3)	0.029 (3)	0.029 (3)	−0.010 (2)	0.009 (2)	−0.006 (2)
C5	0.020 (2)	0.023 (2)	0.029 (2)	0.0004 (18)	0.0019 (19)	−0.001 (2)
C6	0.019 (2)	0.020 (2)	0.023 (2)	−0.0048 (17)	0.0005 (18)	−0.002 (2)
C7	0.017 (2)	0.022 (2)	0.024 (2)	−0.0012 (18)	0.0015 (18)	−0.001 (2)
C8	0.021 (2)	0.022 (2)	0.022 (2)	−0.0016 (17)	0.0048 (19)	−0.0026 (18)
C9	0.017 (2)	0.027 (3)	0.034 (3)	0.0025 (17)	0.004 (2)	−0.003 (2)
C10	0.019 (2)	0.027 (3)	0.030 (3)	0.0007 (19)	−0.004 (2)	0.006 (2)
O1	0.0238 (18)	0.034 (2)	0.0227 (17)	0.0080 (15)	0.0066 (14)	0.0031 (16)
C11	0.023 (2)	0.028 (4)	0.025 (2)	0.0073 (19)	0.0073 (16)	−0.005 (2)
C12	0.030 (3)	0.020 (3)	0.023 (2)	0.0027 (19)	0.007 (2)	0.000 (2)
O2	0.0210 (14)	0.0277 (18)	0.0229 (13)	0.0001 (19)	0.0055 (11)	−0.005 (2)
O3	0.032 (2)	0.031 (2)	0.043 (2)	−0.0020 (17)	0.0094 (17)	−0.0116 (18)
C13	0.024 (2)	0.029 (2)	0.023 (2)	−0.0035 (18)	0.0049 (19)	−0.0020 (19)
C14	0.024 (2)	0.051 (3)	0.029 (2)	0.002 (4)	0.0108 (17)	−0.011 (4)
C15	0.026 (2)	0.036 (3)	0.029 (2)	−0.002 (3)	0.0050 (17)	−0.003 (3)

Geometric parameters (Å, º)

Br1—C7	1.891 (5)	C10—H10	0.9500
C1—C2	1.414 (7)	O1—C11	1.426 (5)
C1—C10	1.419 (7)	C11—C12	1.521 (7)
C1—C6	1.422 (7)	C11—H11A	0.9900
C2—C3	1.358 (8)	C11—H11B	0.9900
C2—H2	0.9500	C12—O3	1.201 (6)
C3—C4	1.404 (9)	C12—O2	1.337 (6)
C3—H3	0.9500	O2—C13	1.474 (6)
C4—C5	1.376 (7)	C13—C14	1.510 (7)
C4—H4	0.9500	C13—C15	1.524 (7)
C5—C6	1.430 (7)	C13—H13	1.0000
C5—H5	0.9500	C14—H14A	0.9800
C6—C7	1.422 (6)	C14—H14B	0.9800
C7—C8	1.374 (6)	C14—H14C	0.9800
C8—O1	1.371 (6)	C15—H15A	0.9800
C8—C9	1.420 (7)	C15—H15B	0.9800
C9—C10	1.367 (7)	C15—H15C	0.9800
C9—H9	0.9500
C2—C1—C10	121.8 (5)	C8—O1—C11	118.6 (4)
C2—C1—C6	119.6 (5)	O1—C11—C12	111.4 (4)
C10—C1—C6	118.6 (4)	O1—C11—H11A	109.3
C3—C2—C1	121.2 (5)	C12—C11—H11A	109.3
C3—C2—H2	119.4	O1—C11—H11B	109.3
C1—C2—H2	119.4	C12—C11—H11B	109.3
C2—C3—C4	119.7 (5)	H11A—C11—H11B	108.0
C2—C3—H3	120.2	O3—C12—O2	125.4 (5)
C4—C3—H3	120.2	O3—C12—C11	125.1 (4)
C5—C4—C3	121.6 (5)	O2—C12—C11	109.4 (4)
C5—C4—H4	119.2	C12—O2—C13	116.7 (4)
C3—C4—H4	119.2	O2—C13—C14	106.1 (4)
C4—C5—C6	119.6 (5)	O2—C13—C15	108.9 (4)
C4—C5—H5	120.2	C14—C13—C15	112.7 (5)
C6—C5—H5	120.2	O2—C13—H13	109.7
C1—C6—C7	118.4 (4)	C14—C13—H13	109.7
C1—C6—C5	118.3 (4)	C15—C13—H13	109.7
C7—C6—C5	123.3 (4)	C13—C14—H14A	109.5
C8—C7—C6	121.7 (4)	C13—C14—H14B	109.5
C8—C7—Br1	118.3 (4)	H14A—C14—H14B	109.5
C6—C7—Br1	120.0 (3)	C13—C14—H14C	109.5
O1—C8—C7	117.2 (4)	H14A—C14—H14C	109.5
O1—C8—C9	123.2 (4)	H14B—C14—H14C	109.5
C7—C8—C9	119.6 (4)	C13—C15—H15A	109.5
C10—C9—C8	119.8 (5)	C13—C15—H15B	109.5
C10—C9—H9	120.1	H15A—C15—H15B	109.5
C8—C9—H9	120.1	C13—C15—H15C	109.5
C9—C10—C1	121.9 (5)	H15A—C15—H15C	109.5
C9—C10—H10	119.1	H15B—C15—H15C	109.5
C1—C10—H10	119.1

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5···Br1	0.95	2.76	3.182 (5)	108