Bromine → 3-Bromo-5-(pyrazin-2-yl)pyridin-2(1H)-one

HRID 1388664Notes

Reaction equation

HRID 1388664 reaction equation
[Br:1]Br.[N:3]1[CH:8]=[CH:7][N:6]=[CH:5][C:4]=1[C:9]1[CH:10]=[CH:11][C:12](=[O:15])[NH:13][CH:14]=1>C(O)(=O)C>[Br:1][C:11]1[C:12](=[O:15])[NH:13][CH:14]=[C:9]([C:4]2[CH:5]=[N:6][CH:7]=[CH:8][N:3]=2)[CH:10]=1

Participants

4

Reactant 2

HCID 24408BromineHCID 233188115-(Pyrazin-2-yl)pyridin-2(1H)-one

Product 1

HCID 136451023-Bromo-5-(pyrazin-2-yl)pyridin-2(1H)-one

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
50 °C

Procedure

3 ml of bromine are added to a stirred suspension of 5-(2-pyrazinyl)-2(1H)-pyridone (9.0 g) in 300 ml of glacial acetic acid warmed to a temperature of 50° C. The mixture is stirred at RT overnight, cooled in an ice bath to 16° C. and filtered. The filtered yellow solid is suspended in 100 ml of distilled H2O, to which sodium bisulfite is gradually added until the solid appears tan. A saturated potassium carbonate solution is slowly added until the pH is adjusted to 7.4, and the suspension is filtered. The filtered solid is washed with H2O and dried under high vacuum at 100° C. for 4 hours, giving the desired 3-bromo-5-(2-pyrazinyl)-2(1H)-pyridone which is recrystallized from methanol, M.P. >250° C.

Workup

  1. temperaturecooled in an ice bath to 16° C.
  2. filtrationfiltered
  3. additionis gradually added until the solid
  4. additionA saturated potassium carbonate solution is slowly added until the pH
  5. filtrationthe suspension is filtered
  6. washThe filtered solid is washed with H2O
  7. customdried under high vacuum at 100° C. for 4 hours

Sources & evidence

ORD record
ord-284892566b594c60b829966db3f76c88
Source dataset
uspto-grants-1984_02
Patent number
US04432979

Reaction notes

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