4-Acetylpyridine → 2-Bromo-1-(pyridin-4-yl)ethanone

HRID 1592966Notes

Reaction equation

HRID 1592966 reaction equation
[C:1]([C:4]1[CH:9]=[CH:8][N:7]=[CH:6][CH:5]=1)(=[O:3])[CH3:2].[Br:10]Br>Br>[Br:10][CH2:2][C:1]([C:4]1[CH:9]=[CH:8][N:7]=[CH:6][CH:5]=1)=[O:3]

Participants

4

Reactant 2

HCID 142824-AcetylpyridineHCID 24408Bromine

Product 1

HCID 4070312-Bromo-1-(pyridin-4-yl)ethanone

Reagents, catalysts & solvents 1

HCID 260Hydrogen BromideSolvent2×

Conditions

Temperature
70 °C

Procedure

To a solution of 18.2 g (150 mmol) 4-acetylpyridine (6-1) in 20 mL 48% HBr was added a 5 mL solution of 7.70 mL bromine in 48% HBr dropwise while heating in a 70° C. oil bath. A thick precipitate formed about midway through the addition, but the reaction was allowed to stir an additional 2 h at 70° C. The reaction was cooled and the precipitate was collected by filtration and washed 3×20 mL with a 1:1 methanol:Et2O solution to provide pure 2-bromo-1-pyridin-4-ylethanone (6-2) after drying under high vacuum: 1H NMR (400 MHz, DMSO-d6) δ 9.0 (d, J=3 Hz, 2H), 8.07 (d, J=3 Hz, 2H), 5.03 (s, 2H).

Workup

  1. customA thick precipitate formed about midway through the addition
  2. temperatureThe reaction was cooled
  3. filtrationthe precipitate was collected by filtration
  4. washwashed 3×20 mL with a 1:1 methanol

Sources & evidence

ORD record
ord-3ef70b9e5a464e288592784db58b4abc
Source dataset
uspto-grants-2007_11
Patent number
US07294640B2

Reaction notes

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