Boron tribromide → 1,3-Benzenediol, 5-chloro-

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Reaction Steps

A solution of 5-chloro-1,3-dimethoxybenzene (5.41 g, 31.3 mM) in methylene chloride (75 mL) at −78° C. was stirred with a 1M solution of BBr3 in methylene chloride (63 mL) for 45 minutes. The reaction was allowed to warm to room temperature overnight and diluted with water (75 mL). The layers were separated and the aqueous layer washed two times with methylene chloride. The aqueous layer was acidified with 1N HCl and extracted 3 times with ethyl acetate. The combined organic layers were washed with 1N sodium thiosulfate (1×35 mL) and water (1×25 mL). The organic layer was dried (MgSO4), filtered and concentrated under reduced pressure and purified by chromatography (methylene chloride/acetone) to provide the titled compound. MS ESI(−)) m/e 143 (M−H)+; 1H NMR (300 MHz, CDCl3) δ 6.45 (d, 2H), 6.25 (t, 1H), 5.41 (bs, 2H).

Provenance & Evidence