反应详情

5-Bromo-2-furoic acid (300 mg, 1.57 mmol) and sodium bicarbonate (316 mg, 3.76 mmol) was stirred in 3.5 mL of pentane/water (2:5) at room temperature for 5 minutes. 1-Chloromethyl-4-fluoro-1,4-diazobicyclo[2.2.2]octane bis-(tetrafluoroborate (“Selectfluor®”) (668 mg, 1.88 mmol) was added, and the mixture was stirred for another hour at room temperature. The pentane layer containing 5-bromo-2-fluorofuran was separated from the mixture, dried (MgSO4), and used for next step directly. The pentane solution of 5-bromo-2-fluorofuran was diluted with 3 mL of anhydrous ether, and cooled to −78° C. under nitrogen. n-Butyllithium (1.6M, 0.25 mL, 0.39 mmol) was added, and the solution was stirred at −78° C. for 10 minutes. Tri-n-butylstannyl chloride (127 mg, 0.39 mmol) then was added, and the solution was allowed to warm to room temperature, and stirred for another 20 minutes. The mixture was quenched and washed with 1N sodium hydroxide, then the organic layer was separated, dried through MgSO4, and filtered, and then the solvent was evaporated to give the sub-title compound (155 mg) as a brown oil which was used without further purification for the next step.

1. customwas separated from the mixture
2. dry with materialdried (MgSO4)
3. additionThe pentane solution of 5-bromo-2-fluorofuran was diluted with 3 mL of anhydrous ether
4. temperaturecooled to −78° C. under nitrogen
5. stirringthe solution was stirred at −78° C. for 10 minutes
6. temperatureto warm to room temperature
7. stirringstirred for another 20 minutes
8. customThe mixture was quenched
9. washwashed with 1N sodium hydroxide
10. customthe organic layer was separated
11. dry with materialdried through MgSO4
12. filtrationfiltered
13. customthe solvent was evaporated