反应详情

温度

-70 °C

A stirred solution of 7-bromobenzofuran (493 mg, 2.5 mmol) in dry THF (5 mL) was cooled to −70° C. and 2M LDA in 1:1 THF/heptane (1.4 mL, 2.8 mmol) was added dropwise over 2 min. The mixture was stirred at −70° C. for 1 h and methyl iodide (0.19 mL, 3.0 mmol) was added. The mixture was stirred at −70° C. for 3 h and at 0° C. for 1 h. The mixture was poured into 5% aq HCl (60 mL) and extracted with ether (2×50 mL). The combined ether extracts were washed with sat'd aq NaHCO3 (20 mL) and dried over MgSO4. Removal of the solvent left an oil (470 mg) which was purified by chromatography on a 40-g silica cartridge eluted with hexanes to afford 7-bromo-2-methylbenzofuran (277 mg, 52%, estimated purity ˜80%).

1. stirringThe mixture was stirred at −70° C. for 3 h and at 0° C. for 1 h
2. extractionextracted with ether (2×50 mL)
3. washThe combined ether extracts were washed with sat'd aq NaHCO3 (20 mL)
4. dry with materialdried over MgSO4
5. customRemoval of the solvent
6. waitleft an oil (470 mg) which
7. customwas purified by chromatography on a 40-g silica cartridge
8. washeluted with hexanes