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

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).

1. additionwas added
2. temperaturethe reaction mixture was re-cooled to 0° C.
3. customAfter two hours the reaction mixture was partitioned between ethyl acetate and water
4. washthe organic layer washed with brine
5. dry with materialdried over magnesium sulfate
6. customevaporated in vacuo
7. customThe crude product was purified via flash chromatography on silica gel (0 to 30% ethyl acetate in heptanes)

ORD record

ord-779c11fc489545f0a18c0a79c0d0365e

Source dataset

uspto-grants-2015_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08999998B2