反応 #2353414

反応方程式

methyl iodide

LDA

THF heptane

7-bromobenzofuran

HCl

→

7-bromo-2-methylbenzofuran

収率 52.0%

溶媒

THF

反応条件

後処理

1. 1
   workup.STIRRINGThe mixture was stirred at −70° C. for 3 h and at 0° C. for 1 h
2. 2
   抽出extracted with ether (2×50 mL)
3. 3
   洗浄The combined ether extracts were washed with sat'd aq NaHCO3 (20 mL)
4. 4
   乾燥dried over MgSO4
5. 5
   その他Removal of the solvent
6. 6
   workup.WAITleft an oil (470 mg) which
7. 7
   その他was purified by chromatography on a 40-g silica cartridge
8. 8
   洗浄eluted with hexanes

実験手順

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%).

出典