Reaktion #57065

Reaktionsgleichung

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

furan

BuLi

→

24

Ausbeute 70.0%

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

Ausbeute 70.0%

Lösungsmittel

Et2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto warm to room temperature
2. 2
   workup.WAITAfter 2 hours
3. 3
   Sonstigethe reaction mixture was quenched with water dropwise
4. 4
   workup.ADDITIONwas poured into water
5. 5
   SonstigeThe organic layer was separated
6. 6
   Extraktionthe aqueous layer was extracted three times with Et2O
7. 7
   WaschenThe combined organic layers were washed with brine
8. 8
   Trocknendried over MgSO4
9. 9
   Einengenconcentrated
10. 10
    Sonstigechromatographed (25% ethyl acetate:hexanes) on silica gel

Vorschrift

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.

Quelle