Реакция #57065

Уравнение реакции

3,4-difluoro-1,2-dibromo-benzene

furan

BuLi

→

24

Выход 70.0%

6,7-Difluoro-1,4-epoxy-1,4-dihydronaphthalene

Выход 70.0%

Растворители

Et2O

Условия реакции

Обработка

1. 1
   Температураto warm to room temperature
2. 2
   workup.WAITAfter 2 hours
3. 3
   Другоеthe reaction mixture was quenched with water dropwise
4. 4
   workup.ADDITIONwas poured into water
5. 5
   ДругоеThe organic layer was separated
6. 6
   Экстракцияthe aqueous layer was extracted three times with Et2O
7. 7
   ПромывкаThe combined organic layers were washed with brine
8. 8
   Сушкаdried over MgSO4
9. 9
   Концентрированиеconcentrated
10. 10
    Другоеchromatographed (25% ethyl acetate:hexanes) on silica gel

Методика

To 3,4-difluoro-1,2-dibromo-benzene (0.75 g, 2.78 mmol) and furan (1 mL, 14.7 mmol) in Et2O (15 mL) at −78° C. was added BuLi (1.1 mL, 2.5M in hexanes, 2.75 mmol) dropwise. The reaction was stirred for two hours at −78° C. and then was allowed to warm to room temperature. After 2 hours, the reaction mixture was quenched with water dropwise and then was poured into water. The organic layer was separated and the aqueous layer was extracted three times with Et2O. The combined organic layers were washed with brine, dried over MgSO4, concentrated and chromatographed (25% ethyl acetate:hexanes) on silica gel to give 24 (350 mg, 70%) as a colourless oil. Rf=0.21 on silica gel (20% ethyl acetate:hexanes); bp 40° C. @ 0.5 mmHg]; IR (neat, cm−1), 3017 (M), 1624 (s), 1465 (s), 1365 (s), 1253 (s), 1190 (m), 1040 (s), 857 (s). 1H NMR (400Mz, CDCl3) δ 7.06 (2H, dd, JH-F=7.7, 7.7 Hz), 7.01 (2H, s), 5.67 (2H, s); 13C NMR (400 MHz, CDCl3) δ 147.2 (dd, JC-F=247.9, 14.5 Hz), 145.1 (dd, JC-F=4.3, 4.3 Hz), 143.1, 110.8 (m), 82.1.HRMS calcd for C10H6O (M+): 180.0387. Found: 180.0394.

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