To a solution of 1,12-Dodecanediol (28 g, 0.14 mol) in toluene (600 mL) was added concentrated HBr [27.5 mL of a 48 % (9 M) aqueous solution, 0.162 mol]. The heterogeneous mixture was heated at reflux for 36 h, after which TLC analysis showed that 20 % of the diol remained. Thus, a further quantity of HBr (10 mL, 0.09 mol) was added, and the mixture was heated at reflux for 12 h, after which TLC analysis showed no remaining diol. The reaction mixture was allowed to return to room temperature, and the phases were separated. The organic layer was diluted with ether (200 mL) and washed with 1 M NaOH solution (200 mL) and brine solution (300 mL). Drying over anhydrous Na2SO4, filtration, and concentration of the organic layer gave a yellow oil, which was purified by column chromatography using hexane/ether as eluent (7:3) to provide 12-Bromo-1-dodecanol as a pale yellow oil.
