Reaktion #7224

Reaktionsgleichung

2-Bromo-3-but-3-enyloxy-pyridine

triphenylphosphine

potassium acetate

→

title compound

Ausbeute 52.8%

4-Methylene-3,4-dihydro-2H-pyrano[3,2-b]pyridine

Ausbeute 52.8%

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigedegassed DMF (2 mL)
2. 2
   Sonstigeto seal the tube
3. 3
   Sonstigethe contents were then flushed several times with argon
4. 4
   Sonstigeclosed tightly with a cap
5. 5
   Temperaturcooled to room temperature
6. 6
   workup.ADDITIONthen diluted with 200 mL ethyl acetate
7. 7
   WaschenThe organic layer was washed with sat. NaHCO3
8. 8
   Trocknenbrine and dried over Na2SO4
9. 9
   SonstigeEvaporation of the solvent and purification of the residue by flash chromatography on silica gel

Vorschrift

A reaction tube was charged with 2-Bromo-3-but-3-enyloxy-pyridine (106 mg, 0.45 mmol), triphenylphosphine (35 mg, 0.133 mmol), palladium acetate (10 mg, 0.044 mmol), potassium acetate (223 mg, 2.27 mmol), tetraethylammonium chloride hydrate (151 mg, 0.91 mmol) and degassed DMF (2 mL). A rubber septum was used to seal the tube and the contents were then flushed several times with argon, then closed tightly with a cap. The mixture was heated at 110° C. under argon for 18 hours, cooled to room temperature then diluted with 200 mL ethyl acetate. The organic layer was washed with sat. NaHCO3, then brine and dried over Na2SO4. Evaporation of the solvent and purification of the residue by flash chromatography on silica gel, using 5% ethyl acetate in hexanes, afforded the title compound (35 mg, 52%) as white solid. 1H NMR (CDCl3) □ 2.79–2.84 (m, 2H), 4.25 (t, 2H, J=5.7 Hz), 5.06–5.08 (m, 1H), 6.19 (d, 1H, J=1.6 Hz), 7.08–7.17 (m, 2H), 8.20 (dd, 1H, J=1.6, 4.7 Hz); ES-MS m/z 148.0 (M+H).

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