反応 #7224

反応方程式

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

triphenylphosphine

potassium acetate

→

title compound

収率 52.8%

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

収率 52.8%

反応条件

後処理

1. 1
   その他degassed DMF (2 mL)
2. 2
   その他to seal the tube
3. 3
   その他the contents were then flushed several times with argon
4. 4
   その他closed tightly with a cap
5. 5
   温度cooled to room temperature
6. 6
   workup.ADDITIONthen diluted with 200 mL ethyl acetate
7. 7
   洗浄The organic layer was washed with sat. NaHCO3
8. 8
   乾燥brine and dried over Na2SO4
9. 9
   その他Evaporation of the solvent and purification of the residue by flash chromatography on silica gel

実験手順

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).

出典