Pyridinium hydrobromide → 4-bromo-5-methoxypyridin-2(1H)-one

HRID 56835Notes

Reaction equation

HRID 56835 reaction equation
Br.[NH+]1C=CC=CC=1.[Br:8][C:9]1[C:14]([O:15][CH3:16])=[CH:13][N:12]=[C:11]([O:17]C)[CH:10]=1>CN(C)C=O>[Br:8][C:9]1[C:14]([O:15][CH3:16])=[CH:13][NH:12][C:11](=[O:17])[CH:10]=1

Participants

4

Reactant 2

HCID 21226041Pyridinium hydrobromideHCID 846833504-Bromo-2,5-dimethoxypyridine

Product 1

HCID 1176225904-bromo-5-methoxypyridin-2(1H)-one

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
100 °C

Procedure

2.82 g (176 mmol, 20 eq.) of pyridinium hydrobromide were added to a solution of 1.94 g (8.81 mmol) of 4-bromo-2,5-dimethoxypyridine in 80 ml of dimethylformamide, the mixture was stirred at 100° C. for 3 h and concentrated under reduced pressure. The residue was triturated with 50 ml of water, filtered off, washed with water and dried under reduced pressure. The filtrate was extracted twice with dichloromethane/methanol (10:1). The combined organic phases were dried (sodium sulphate), filtered, concentrated under reduced pressure and dried. Yield: 771 mg (43% of theory) and 465 mg (purity 88%, 23% of theory)

Workup

  1. concentrationconcentrated under reduced pressure
  2. customThe residue was triturated with 50 ml of water
  3. filtrationfiltered off
  4. washwashed with water
  5. customdried under reduced pressure
  6. extractionThe filtrate was extracted twice with dichloromethane/methanol (10:1)
  7. dry with materialThe combined organic phases were dried (sodium sulphate)
  8. filtrationfiltered
  9. concentrationconcentrated under reduced pressure
  10. customdried

Sources & evidence

ORD record
ord-30975c292b814143a149ac6091aa4b33
Source dataset
uspto-grants-2016_09
Patent number
US09434690B2

Reaction notes

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