反应详情

A suspension of 2-chloro-4-pyridinemethanol (8.0 g, 55.9 mmol), NBS (14.9 g, 83.9 mmol), and K2CO3 (11.75 g, 97.1 mmol) in EtOAc was refluxed for 3 h. A second portion of NBS (14.9 g, 83.9 mmol) and Na2CO3 (12.0 g, 114 mmol) were added and the reaction was heated to reflux for an additional 3.5 h, cooled and filtered through a pad of celite. The filtrate, after concentrattion to a small volume, was subjected to flash chromatography eluting with 0.5-4% CH3OH/CH2Cl2. The fractions containing product were combined, washed successively with sat aq NaHCO3 10% Na2S2O3, and brine, dried (MgSO4) and concentrated in vacuo to give the title compound as a light yellow solid; yield 5.3 g (67%). 1H NMR (CDCl3) δ10.06 (s, 1H), 8.66 (d, 1H, J=5.0 Hz), 7.76 (s, 1H), 7.66 (d, 1H, J=5.0 Hz).

1. temperaturewas refluxed for 3 h
2. temperaturethe reaction was heated
3. temperatureto reflux for an additional 3.5 h
4. temperaturecooled
5. filtrationfiltered through a pad of celite
6. washeluting with 0.5-4% CH3OH/CH2Cl2
7. additionThe fractions containing product
8. washwashed successively with sat aq NaHCO3 10% Na2S2O3, and brine
9. dry with materialdried (MgSO4)
10. concentrationconcentrated in vacuo