Acetylpyrazine → 2-Bromo-1-pyrazin-2-yl-ethanone

HRID 2235065Notes

Reaction equation

HRID 2235065 reaction equation
[C:1]([C:4]1[CH:9]=[N:8][CH:7]=[CH:6][N:5]=1)(=[O:3])[CH3:2].[Br-:10].[Br-].[Br-].[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>C(O)(=O)C>[Br:10][CH2:2][C:1]([C:4]1[CH:9]=[N:8][CH:7]=[CH:6][N:5]=1)=[O:3]

Participants

4

Reactant 2

HCID 30914AcetylpyrazineHCID 21124087Pyridiniumtribromide

Product 1

HCID 158231122-Bromo-1-pyrazin-2-yl-ethanoneYield 38.3%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Acetylpyrazine (244 mg, 2.0 mmol) was suspended in glacial acetic acid (10 mL) and treated with pyridinium tribromide (640 mg, 2.0 mmol). The reaction mixture was stirred overnight. The solvent was removed under reduced pressure and the residue was purified by silica gel chromatography, eluting with 1:1 hexane/ethyl acetate, to provide 2-(2-bromoacetyl)pyrazine as a brown solid (154 mg, 38%). 1H NMR (200 MHz, DMSO-d6) δ 9.16 (d, J=1.5 Hz, 1H), 8.94 (d, J=2.4 Hz, 1H), 8.82 (dd, J=1.5, 2.4 Hz, 1H), 4.99 (s, 2H).

Workup

  1. customThe solvent was removed under reduced pressure
  2. customthe residue was purified by silica gel chromatography
  3. washeluting with 1:1 hexane/ethyl acetate

Sources & evidence

ORD record
ord-5ff6608756764ec69a0f99499c9caf61
Source dataset
uspto-grants-2010_05
Patent number
US07714003B2

Reaction notes

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