Reaktion #67423

Reaktionsgleichung

water

3-fluoro-4,5-dihydroxy-benzaldehyde

Cs2CO3

→

7-fluoro-benzo[1,3]dioxole-5-carbaldehyde

Ausbeute 49.6%

Lösungsmittel

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   ExtraktionThe resulting mixture was extracted with EtOAc (50 mL×3)
2. 2
   WaschenThe combined organic layers were washed with brine (100 mL)
3. 3
   Trocknendried over Na2SO4
4. 4
   Sonstigeevaporated under reduced pressure
5. 5
   Sonstigeto give the crude product, which
6. 6
   Sonstigewas purified by column chromatography on silica gel (petroleum ether/E.A.=10/1)

Vorschrift

To a solution of 3-fluoro-4,5-dihydroxy-benzaldehyde (1.5 g, 9.6 mmol) and BrClCH2 (4.9 g, 38.5 mmol) in dry DMF (50 mL) was added Cs2CO3 (12.6 g, 39 mmol). The mixture was stirred at 60° C. overnight and was then poured into water. The resulting mixture was extracted with EtOAc (50 mL×3). The combined organic layers were washed with brine (100 mL), dried over Na2SO4 and evaporated under reduced pressure to give the crude product, which was purified by column chromatography on silica gel (petroleum ether/E.A.=10/1) to afford 7-fluoro-benzo[1,3]dioxole-5-carbaldehyde (0.80 g, 49%). 1H NMR (300 MHz, CDCl3) δ 9.78 (d, J=0.9 Hz, 1H), 7.26 (dd, J=1.5, 9.3 Hz, 1H), 7.19 (d, J=1.2 Hz, 1H), 6.16 (s, 2H).

Quelle