Methyl 2-(5-bromo-2-methyl­naphtho[2,1-b]furan-1-yl)acetate

Martyn Jevric; Dennis K Taylor; Edward R T Tiekink

doi:10.1107/S1600536808015511

. 2008 May 30;64(Pt 6):o1168. doi: 10.1107/S1600536808015511

Methyl 2-(5-bromo-2-methylnaphtho[2,1-b]furan-1-yl)acetate

Martyn Jevric ^a, Dennis K Taylor ^b,^‡, Edward R T Tiekink ^c,^*

PMCID: PMC2961467 PMID: 21202675

Abstract

The three fused six-, six- and five-membered rings in the title compound, C₁₆H₁₃BrO₃, are coplanar, the CH₂C(=O)OCH₃ residue being twisted out of this plane [dihedral angle = −26.9 (4)°]. Centrosymmetric dimers are found in the crystal structure stabilized by C—H⋯O interactions involving the furan O atom.

Related literature

For related literature, see: Chatterjea et al. (1979 ▶); Einhorn et al. (1983 ▶); Monte et al. (1996 ▶); Jevric et al. (2008 ▶).

Experimental

Crystal data

C₁₆H₁₃BrO₃
M _r = 333.17
Monoclinic,
a = 17.050 (2) Å
b = 14.5064 (17) Å
c = 5.3660 (7) Å
β = 96.443 (3)°
V = 1318.8 (3) Å³
Z = 4
Mo Kα radiation
μ = 3.12 mm⁻¹
T = 223 (2) K
0.68 × 0.18 × 0.16 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.492, T _max = 1.000 (expected range = 0.299–0.607)
10676 measured reflections
3817 independent reflections
2967 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.136
S = 1.13
3817 reflections
183 parameters
H-atom parameters constrained
Δρ_max = 0.47 e Å⁻³
Δρ_min = −0.77 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SIR92 (Altomare et al., 1994 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPII (Johnson, 1976 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808015511/su2059sup1.cif

e-64-o1168-sup1.cif^{(16.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808015511/su2059Isup2.hkl

e-64-o1168-Isup2.hkl^{(187.1KB, hkl)}

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
C4—H4⋯O3ⁱ	0.94	2.58	3.468 (4)	157

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Symmetry code: (i) Inline graphic .

Acknowledgments

We are grateful to the Australian Research Council for financial support.

supplementary crystallographic information

Comment

Little has been done on observing aromatic electrophillic substitutions on polycyclic aromatic systems related to 1 shown in Fig. 3 (Chatterjea et al., 1979). Previous work showed that substitution should proceed at position five in the ring system of 1 (Chatterjea et al., 1979). Treatment of 1 with bromine in acetic acid according to a literature procedure (Einhorn et al., 1983 & Monte et al., 1996) gave the title compound (I) as the sole isolatable product. ¹H NMR analysis of (I) showed five aromatic proton signals, two of which experienced two large ortho couplings and one a singlet (δ 7.81). This coupling pattern indicated that an aromatic electrophilic substitution had occurred on the ring adjoining the furan. However, although all signals were unobscured it was not possible to assign the peri proton as no detectable cross-peak in the ROESY spectrum was observed. X-ray crystallography showed that the position of the bromine substitution was in accordance with previous literature (Chatterjea et al., 1979).

Compound (I), Fig. 1, is comprised of three fused rings; two six-membered rings (A & B) and one five-membered ring (C). The respective A/B, A/C & B/C dihedral angles between their least-squares planes are 1.88 (13), 4.16 (15) & 2.48 (14)°. The CH₂C(=O)OCH₃ residue is twisted out of the tricyclic system, as seen in the value of the C1/C11/C12/O12 torsion angle of -26.9 (4)°. The crystal packing features centrosymmetric dimers consolidated by C—H···O contacts involving the furan-O atom; Table 1 and Fig. 2.

The structure ofthe related compound 2-(2-methylnaphtho[2,1-b]furan-1-yl)acetic acid has been reported in the preceding paper (Jevric et al., 2008).

Experimental

Compound (I) was formed (Einhorn et al., 1983 & Monte et al., 1996) in 88% yield as a colourless solid recrystallized from n-heptane; m.p.: 391 - 393 K. R_f = 0.24 (12% acetone in hexane). IR (CH₂Cl₂, cm^-1) 1741, 1618, 1577, 1521. ¹H NMR (d₆-benzene, 600 MHz) δ 2.00 (s, 3H), 3.21 (s, 3H), 3.41 (s, 2H), 7.27 (ddd, J = 7.0, 7.0, 1.2 Hz, 1H), 7.38 (ddd, J = 7.0, 7.0, 1.2 Hz, 1H), 7.81 (s, 1H), 8.36 (dd, J = 7.0, 1.2 Hz, 1H), 8.46 (dd, J = 7.0, 1.2 Hz, 1H) p.p.m.. ¹³C NMR (CDCl₃, 50 MHz) δ 11.9, 31.4, 52.3, 109.5, 116.5, 118.1, 122.3, 123.1, 125.2, 126.9, 128.3, 128.4, 128.8, 150.7, 152.9, 171.3 p.p.m.. MS m/z (%): 332 (M+, 100), 273 (93), 259 (25), 194 (37), 165 (62). HRMS, C₁₆H₁₃BrO₃: calcd, 332.0049; found 332.0062.