Methanol → 2,6-Dibromo-4-methoxypyridine

HRID 1908821Notes

Reaction equation

HRID 1908821 reaction equation
[CH3:1][OH:2].[H-].[Na+].[Br:5][C:6]1[CH:11]=[C:10]([N+]([O-])=O)[CH:9]=[C:8]([Br:15])[N:7]=1>>[Br:5][C:6]1[CH:11]=[C:10]([O:2][CH3:1])[CH:9]=[C:8]([Br:15])[N:7]=1

Participants

4

Procedure

Methanol (1.48 g, 46.1 mmol) is slowly added to a cooled suspension (0° C.) of NaH (2.12 g, 53.2 mmol, 60% dispersion in mineral oil, washed with hexane prior to use) in THF (20 mL). Upon completion of the addition the mixture is stirred at 0° C. for 150 min before 2,6-dibromo-4-nitropyridine (10.0 g, 35.4 mmol) is added. The temperature rises to 14° C. The mixture is stirred at rt for 3 h before the reaction is quenched with sat. aq. NH4Cl solution. The mixture is diluted with water and extracted twice with EA (250 mL). The combined org. extracts are dried over MgSO4, filtered and concentrated. The crude product is purified by CC on silica gel eluting with DCM to give 2,6-dibromo-4-methoxy-pyridine (6.43 g) as an off-white solid; LC-MS: tR=0.90 min, [M+1]+=267.75.

Workup

  1. washwashed with hexane
  2. additionUpon completion of the addition the mixture
  3. additionis added
  4. customrises to 14° C
  5. customis quenched with sat. aq. NH4Cl solution
  6. additionThe mixture is diluted with water
  7. extractionextracted twice with EA (250 mL)
  8. dry with materialextracts are dried over MgSO4
  9. filtrationfiltered
  10. concentrationconcentrated
  11. customThe crude product is purified by CC on silica gel eluting with DCM

Sources & evidence

ORD record
ord-d7da940b1fc84bff8d4cd5288482af3c
Source dataset
uspto-grants-2013_12
Patent number
US08598208B2

Reaction notes

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