Reaktion #67506

Reaktionsgleichung

2-(5-bromo-2-fluoro-phenyl)-propan-2-ol

hydrochinone

H3PO4

→

4-Bromo-1-fluoro-2-isopropenyl-benzene

Lösungsmittel

CH2Cl2

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe resulting reaction mixture
2. 2
   workup.ADDITIONThe mixture was poured onto ice-water
3. 3
   Extraktionextracted with CH2Cl2
4. 4
   WaschenThe organic phases were washed with 2N aqueous NaOH and water
5. 5
   Trocknendried over MgSO4
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated
8. 8
   workup.DISSOLUTIONThe crude product was dissolved in hexane
9. 9
   Filtrationfiltered through a plough of silica gel
10. 10
    Sonstigeto obtain
11. 11
    Einengenafter concentration at 600 mbar the title compound as a colorless oil
12. 12
    SonstigeUPLC RtH5=1.416 min

Vorschrift

To a solution of 2-(5-bromo-2-fluoro-phenyl)-propan-2-ol (119.7 g, 498 mmol) in CH2Cl2 (50 ml) was added hydrochinone (2.74 g, 24.9 mmol) and 250 ml 85% H3PO4. The resulting reaction mixture was stirred for 3.5 h at 50° C. The mixture was poured onto ice-water and extracted with CH2Cl2. The organic phases were washed with 2N aqueous NaOH and water, dried over MgSO4, filtered and concentrated. The crude product was dissolved in hexane and filtered through a plough of silica gel to obtain after concentration at 600 mbar the title compound as a colorless oil: TLC (hexane): Rf=0.52; UPLC RtH5=1.416 min; 1H NMR (360 MHz, CDCl3): δ 7.43 (dd, 1H), 7.37 (m, 1H), 6.94 (dd, 1H), 5.27 (d, 2H), 2.13 (s, 3H).

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