Reaktion #340446

Reaktionsgleichung

5,8-difluoro-6-[(tetrahydro-2H-pyran-2-yloxy)methyl]-2,3-dihydro-1,4-benzodioxine

phosphorous tribromide

→

6-(bromomethyl)-5,8-difluoro-2,3-dihydro-1,4-benzodioxine

Ausbeute 160.0%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenThe solution was concentrated in-vacuo
2. 2
   Sonstigethe residue was partitioned between water and ethyl acetate
3. 3
   ExtraktionThe aqueous layer was extracted with ethyl acetate
4. 4
   WaschenThe combined organic portion was washed with brine
5. 5
   Trocknendried over sodium sulfate
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated in-vacuo

Vorschrift

To a solution of 5,8-difluoro-6-[(tetrahydro-2H-pyran-2-yloxy)methyl]-2,3-dihydro-1,4-benzodioxine (785 mg, 2.74 mmol) in toluene (5 mL) was added phosphorous tribromide (155 μl, 1.65 mmol) and the solution was stirred at room temperature for 15 hrs. The solution was concentrated in-vacuo, and the residue was partitioned between water and ethyl acetate. The aqueous layer was extracted with ethyl acetate. The combined organic portion was washed with brine, dried over sodium sulfate, filtered and concentrated in-vacuo to afford 700 mg, 2.64 mmol (96%) of 6-(bromomethyl)-5,8-difluoro-2,3-dihydro-1,4-benzodioxine as a pale yellow oil. 1H NMR (400 MHz, CDCl3): 6.68 (q, 1H), 4.33 (s, 2H), 4.35 (s, 4H); GC/MS (EI) for C9H7O2F2Br: 265 (M+).

Quelle