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

HRID 643963Notes

Reaction equation

HRID 643963 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-942937c30c0f46efaa67240be726767b
Source dataset
uspto-grants-2010_04
Patent number
US07700635B2

Reaction notes

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