Hydrogen Bromide → 2-Bromo-1-(pyrazin-2-yl)ethan-1-one--hydrogen bromide (1/1)

HRID 521706Notes

Reaction equation

HRID 521706 reaction equation
[C:1]([C:4]1[CH:9]=[N:8][CH:7]=[CH:6][N:5]=1)(=[O:3])[CH3:2].[BrH:10].C1C=C[NH+]=CC=1.[Br:17][Br-]Br.C(OCC)C>C(O)(=O)C>[BrH:17].[Br:10][CH2:2][C:1]([C:4]1[CH:9]=[N:8][CH:7]=[CH:6][N:5]=1)=[O:3]

Participants

5

Reactant 3

HCID 260Hydrogen BromideHCID 3283Diethyl EtherHCID 30914Acetylpyrazine

Product 1

HCID 224987732-Bromo-1-(pyrazin-2-yl)ethan-1-one--hydrogen bromide (1/1)

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To a stirred solution of acetylpyrazine (10 g, 81.88 mmol) in acetic acid (70 mL) is added hydrogen bromide (38% acetic acid solution, 16 mL) followed by pyridinium bromide perbromide (28 g, 83.17 mmol) which is added in a single portion. The reaction is stirred at room temperature for approximately 1.5 hours. A suspension is formed during this time. Diethyl ether is added (500 mL) and the resulting precipitate is collected by filtration. The isolated product is washed with acetonitrile and diethyl ether and is dried under vacuum to give a pale brown solid (23.2 g, quantitative yield). 1H NMR (d6-DMSO) δ 9.19 (1H, m), 8.95 (1H, m), 8.84 (1H, m), 5.02 (2H, s).

Workup

  1. additionis added in a single portion
  2. customA suspension is formed during this time
  3. filtrationthe resulting precipitate is collected by filtration
  4. washThe isolated product is washed with acetonitrile and diethyl ether
  5. customis dried under vacuum

Sources & evidence

ORD record
ord-3b06980eda894e24a24c661c48e4087f
Source dataset
uspto-grants-2016_05
Patent number
US09328124B2

Reaction notes

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