Sodium Carbonate → 2-Chloro-4-pyridinecarboxaldehyde

HRID 344008

Reaction equation

HRID 344008 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+]>C(OCC)(=O)C>[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-pyridinecarboxaldehydeYield 67%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

A suspension of 2-chloro-4-hydroxymethylpyridine (8.0 g, 55.9 mmol), NBS (14.9 g, 83.9 mmol), and K2CO3 (11.75 g, 97.1 mmol) in ethyl acetate was refluxed for 3 h. Another portion of NBS (14.9 g, 83.9 mmol) and Na2CO3 (12.0 g, 114 mmol) was added and heating was continued another 3.5 h. The reaction mixture was cooled, filtered through a pad of celite, concentrated under reduced and chromatographed with 0.5-4% CH3OH/CH2Cl2. The combined fractions were washed with NaHCO3 (sat.), 10% Na2S2O3, and NaCl (sat.), dried, filtered and evaporated to give the title compound as a light yellow solid (5.3 g, 67% yield). 1H NMR (CDCl3): δ 10.06 (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. temperatureheating
  3. temperatureThe reaction mixture was cooled
  4. filtrationfiltered through a pad of celite
  5. concentrationconcentrated under reduced and
  6. customchromatographed with 0.5-4% CH3OH/CH2Cl2
  7. washThe combined fractions were washed with NaHCO3 (sat.), 10% Na2S2O3, and NaCl (sat.)
  8. customdried
  9. filtrationfiltered
  10. customevaporated

Sources & evidence

ORD record
ord-f12ea0af20b142048378d653f7fa356c
Source dataset
uspto-grants-1999_01
Patent number
US05864036

Linked notes

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