1,4-Dibromo-2,5-dibutoxybenzene

The asymmetric unit of the title compound, C14H20Br2O2, contains one half-molecule located on an inversion centre. The molecule is essentially planar, with a maximum deviation from the best plane of the non-H atoms of 0.054 (2) Å for the O atoms. The butoxy group adopts a fully extended all-trans conformation. In the crystal, molecules are connected via C—Br⋯O halogen bonds [Br⋯O = 3.2393 (19) Å] into a two-dimensional corrugated network in the bc plane.


Experimental
The compound was prepared according to previously published work with a slight modification (Lopez-Alvarado et al., 2002). To 1,4-bis(butoxy)benzene (5.00 g, 22.5 mmol) was added dropwise Br 2 (7. 55 g, 47.25 mmol) in glacial acetic acid. The mixture was stirred at room temperature for two hours followed by heating under reflux for another two hours.
The mixture was left to cool to room temperature and water was then added to precipitate the product. The product was filtered, washed with excess water and 1.0 M sodium bicarbonate solution. Slow recrystallization of the product from methanol-ethyl acetate mixture afforded crystals suitable for single X-ray diffraction (yield: 82%).

Refinement
The hydrogen atom positions were calculated geometrically and refined in a riding model approximation with C-H bond lengths in the range 0.93-0.97 Å and U iso (H) = 1.2U eq (C) for aromatic and CH 2 group, and U iso (H) = 1.5U eq (C) for methyl group.
Symmetry code for atoms with the A label: -x, 1 -y, 1 -z.

Figure 2
Crystal packing of the title compound showing intermolecular halogen bonds C1-Br1···O1 [-x,1/2 + y,1/2 -z] resulting in the formation of two-dimensional network along bc plane. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.