3,3′-Dibromo-5,5′-di-tert-butyl-2,2′-dimethoxy­biphen­yl

Matthew I J Polson; Peter J Steel

doi:10.1107/S1600536808002420

. 2008 Jan 30;64(Pt 2):o532. doi: 10.1107/S1600536808002420

3,3′-Dibromo-5,5′-di-tert-butyl-2,2′-dimethoxybiphenyl

Matthew I J Polson ^a,^*, Peter J Steel ^a

PMCID: PMC2960332 PMID: 21201551

Abstract

The title compound, C₂₂H₂₈Br₂O₂, crystallizes in a staggered arrangement to minimize the interactions of its ortho substituents, with a dihedral angle of 84.2 (3)° between the two aromatic rings. Short C—H⋯O hydrogen-bonding interactions between methoxy groups result in a one-dimensional polymeric chain of molecules lying parallel to the b axis. One tert-butyl group is disordered equally over two positions.

Related literature

For a related structure, see: He & Ng (2006 ▶); Steiner (1996 ▶). For an alternative synthesis, see: Katagiri et al. (2006 ▶).

Experimental

Crystal data

C₂₂H₂₈Br₂O₂
M _r = 484.27
Monoclinic,
a = 14.661 (2) Å
b = 13.408 (2) Å
c = 22.489 (3) Å
β = 96.104 (12)°
V = 4395.8 (11) Å³
Z = 8
Mo Kα radiation
μ = 3.70 mm⁻¹
T = 93 (2) K
0.40 × 0.12 × 0.10 mm

Data collection

Bruker APEX2 CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.433, T _max = 0.691
14546 measured reflections
3918 independent reflections
2784 reflections with I > 2σ(I)
R _int = 0.076

Refinement

R[F ² > 2σ(F ²)] = 0.067
wR(F ²) = 0.143
S = 1.10
3918 reflections
293 parameters
54 restraints
H-atom parameters constrained
Δρ_max = 1.10 e Å⁻³
Δρ_min = −0.93 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Version 1.08; Farrugia, 1997 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2008 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808002420/pv2045sup1.cif

e-64-0o532-sup1.cif^{(22KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808002420/pv2045Isup2.hkl

e-64-0o532-Isup2.hkl^{(192.1KB, 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
C31—H31C⋯O10ⁱ	0.98	2.61	2.842 (15)	94
C41—H41C⋯O21ⁱⁱ	0.98	2.57	2.866 (14)	98

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

Acknowledgments

We thank the Foundation of Research Science and Technology for funding. PJS also thanks the Royal Society of New Zealand for the award of a James Cook Research Fellowship.

supplementary crystallographic information

Comment

During attempts to dilithiate 2,6-dibromo-4 - t-butylanisole, the title compound, (I), was serindipitously produced. Compared to the literature methods (Katagiri et al., 2006) this is a much simpler method, wherein the product was acheived in a single step rather than three and with a superior overall yield. The structure adopts a staggered arrangement with a dihedral angle of 84.2 (3)° between the two aromatic rings. A similar angle is found in the literature (80.1°, He & Ng, 2006). Two CH₃···O hydrogen bonds involving both methoxy groups (Table 1) connect the molecules to form a one dimensional polymeric chain parallel to the b axis (Figure 2); similar type of interactions have already been reported (Steiner, 1996).

Experimental

2,6-Dibromo-4 - t-butylanisole (1 g) in THF (40 ml) at 193 K was treated with n-butyl lithium (1.6 M, 2.5 ml). The solution was stirred and allowed to warm up to room temp over 2 hr. The resulting solution was evaporated to dryness, treated with water and extracted with dichloromethane. The organic layer was seperated and purified by column chromotography (SiO₂, dichloromethane). Yeild = 0.6 g (79%).