반응 #449800

반응 방정식

2-chloro-4-pyridinemethanol

NBS

K2CO3

NBS

Na2CO3

→

title compound

2-Chloro-4-pyridinecarboxaldehyde

용매

EtOAc

반응 조건

후처리

1. 1
   온도was refluxed for 3 h
2. 2
   온도the reaction was heated
3. 3
   온도to reflux for an additional 3.5 h
4. 4
   온도cooled
5. 5
   여과filtered through a pad of celite
6. 6
   세척eluting with 0.5-4% CH3OH/CH2Cl2
7. 7
   workup.ADDITIONThe fractions containing product
8. 8
   세척washed successively with sat aq NaHCO3, 10% Na2S2O3, and brine
9. 9
   건조dried (MgSO4)
10. 10
    농축concentrated in vacuo

실험 절차

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).

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