Dichloromethane → 7-Bromo-5-chloro-2,3-dihydrobenzofuran

Beteiligte Stoffe

Reaktionsschritte

To a mixture of 2-bromo-4-chloro-6-(2-hydroxyethyl)phenol (99.8 mg, 0.397 mmol), triethylamine (0.40 mL, 2.9 mmol), and dichloromethane (4 mL) at 0° C. was added methanesulfonyl chloride (56.0 μL, 0.724 mmol). The reaction was stirred at 0° C. for 1.5 hours, at which point additional methane sulfonyl chloride (10 μL) was added and the reaction mixture warmed to room temperature. After stirring overnight, the reaction mixture was re-cooled to 0° C. and triethylamine (0.2 mL) and methanesulfonyl chloride (15 μL) were added. After two hours the reaction mixture was partitioned between ethyl acetate and water, and the organic layer washed with brine, dried over magnesium sulfate, and evaporated in vacuo. The crude product was purified via flash chromatography on silica gel (0 to 30% ethyl acetate in heptanes) to yield 40.0 mg (40%) of 7-bromo-5-chloro-2,3-dihydrobenzofuran. 1H NMR (400 MHz, CDCl3) δ: 7.26 (d, 1H), 7.09 (d, 1H), 4.67 (t, J=8.8, 2H), 3.30 (t, J=8.8, 2H).

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