Iodine → 2-bromo-7-iodo-5H-pyrrolo(2,3-b)pyrazine

HRID 1677375Notes

Reaction equation

HRID 1677375 reaction equation
[Br:1][C:2]1[N:3]=[C:4]2[CH:10]=[CH:9][NH:8][C:5]2=[N:6][CH:7]=1.[OH-].[K+].[I:13]I.S([O-])([O-])(=O)=S.[Na+].[Na+]>CN(C)C=O.C(OCC)(=O)C.O>[Br:1][C:2]1[N:3]=[C:4]2[C:10]([I:13])=[CH:9][NH:8][C:5]2=[N:6][CH:7]=1

Participants

8

Reactant 4

HCID 807IodineHCID 14797Potassium HydroxideHCID 24477Sodium ThiosulfateHCID 250673082-bromo-5H-pyrrolo[2,3-b]pyrazine

Product 1

HCID 441182772-bromo-7-iodo-5H-pyrrolo(2,3-b)pyrazine

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Procedure

1.5 g of 2-bromo-5H-pyrrolo[2,3-b]pyrazine (7.57 mmol, 1 eq) was dissolved in 20 ml of N,N-dimethylformamide. 1.27 g of crushed potassium hydroxide pellets (22.7 mmol, 3 eq) were then added and the mixture was stirred for 10 min. The reaction flask was cooled in an ice bath and 1.92 g of iodine (7.57 mmol, 1 eq) was added in several portions over 1 hr. After 30 min. more the reaction was complete and about 10 ml 1M sodium thiosulfate solution, water and ethyl acetate were added. The layers were separated and the aqueous layer was extracted with ethyl acetate two times more. The combined ethyl acetate layers were washed with water and saturated sodium chloride solution, and then dried over sodium sulfate. After filtration and evaporation of solvent 2.4 g of solid (97%) was obtained and used directly in the next reaction.

Workup

  1. temperatureThe reaction flask was cooled in an ice bath
  2. waitAfter 30 min. more the reaction was complete
  3. customThe layers were separated
  4. extractionthe aqueous layer was extracted with ethyl acetate two times more
  5. washThe combined ethyl acetate layers were washed with water and saturated sodium chloride solution
  6. dry with materialdried over sodium sulfate
  7. filtrationAfter filtration and evaporation of solvent 2.4 g of solid (97%)
  8. customwas obtained
  9. customused directly in the next reaction

Sources & evidence

ORD record
ord-49cca9dd482c451c857497d903c4cee0
Source dataset
uspto-grants-2011_08
Patent number
US08008298B2

Reaction notes

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