Sodium Carbonate → 2-Chloro-4-pyridinecarboxaldehyde

HRID 324703

Reaction equation

HRID 324703 reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([CH2:8][OH:9])[CH:5]=[CH:4][N:3]=1.C1C(=O)N(Br)C(=O)C1.C([O-])([O-])=O.[K+].[K+].C([O-])([O-])=O.[Na+].[Na+]>CCOC(C)=O>[Cl:1][C:2]1[CH:7]=[C:6]([CH:8]=[O:9])[CH:5]=[CH:4][N:3]=1

Participants

6

Reactant 4

HCID 10340Sodium CarbonateHCID 11430Potassium CarbonateHCID 67184N-bromobutanimide2×HCID 7062237(2-Chloropyridin-4-yl)methanol

Product 1

HCID 27629942-Chloro-4-pyridinecarboxaldehyde

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

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).

Workup

  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

Sources & evidence

ORD record
ord-bb2021ce32a34a9d83b9e17c7efcd92c
Source dataset
uspto-grants-2001_04
Patent number
US06218537B1

Linked notes

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