Boron tribromide → 1-(6-Bromohexyl)-2,3-dihydroxybenzene

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Reaction Steps

Boron tribromide (266 mL, 0.266 mol, 1M in methylene chloride) was added dropwise over 1 hour to a cooled (-65°) solution of 40.0 g (0.133 mol) of 1-(6-bromohexyl)-2,3-dimethoxybenzene in 800 mL of anhydrous methylene chloride which was stirred in an argon atmosphere. The cooling bath was then removed and the reaction mixture was stirred for 1.5 hours. After cooling in an ice bath, 100 mL of water and 50 mL of 3N HCl were added and the mixture was stirred for 2 hours. The organic layer was separated, dried and concentrated under reduced pressure to an oil which was purified by HPLC using 5% methanol-chloroform to yield 34.7 g of 1-(6-bromohexyl)-2,3-dihydroxybenzene as an oil. To this was added 32 mL (0.28 mol) of benzyl chloride, 46 g (0.28 mol) of potassium iodide, 122 g (0.88 mol) of potassium carbonate and 700 mL of anhydrous acetone and the reaction mixture was stirred at reflux for 72 hours. The solid was removed by filtration and the filtrate was concentrated under reduced pressure to an oil which was purified by HPLC using 1% ethyl acetate-hexane to give 47 g (74% yield) of 1-(6-Iodohexyl)-2,3-bis-(phenylmethoxy) benzene as an oil. The nmr spectrum was consistent with the structure (CH2I at δ3.14) and the mass spectrum showed the molecular ion at m/e 500 (C26H29IO2).

Provenance & Evidence