Stannane, tributyl(1-ethoxyethenyl)- → 2-Bromo-5-(1-ethoxyethenyl)pyrazine

HRID 520349Notes

Reaction equation

HRID 520349 reaction equation
Br[C:2]1[CH:7]=[N:6][C:5]([Br:8])=[CH:4][N:3]=1.[CH2:9]([O:11][C:12]([Sn](CCCC)(CCCC)CCCC)=[CH2:13])[CH3:10]>CN(C=O)C.CCOC(C)=O.[F-].[K+].Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[Br:8][C:5]1[CH:4]=[N:3][C:2]([C:9]([O:11][CH2:12][CH3:13])=[CH2:10])=[CH:7][N:6]=1

Participants

7

Reactant 2

HCID 619414Stannane, tributyl(1-ethoxyethenyl)-HCID 114704212,5-dibromopyrazine

Product 1

HCID 591665842-Bromo-5-(1-ethoxyethenyl)pyrazineYield 67.6%

Reagents, catalysts & solvents 4

HCID 178418476HCID 178418476, compoundCatalystHCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolventHCID 522689Potassium FluorideSolvent

Conditions

Temperature
100 °C

Procedure

To a solution of 2,5-dibromopyrazine (1 g, 4.20 mmol) in DMF was added 1-ethoxyvinyltri-n-butyltin (1.420 mL, 4.20 mmol) and bis(triphenylphosphine)palladium(II) chloride (0.148 g, 0.210 mmol). The reaction mixture was heated at 100° C. for 4 hrs. The reaction mixture was diluted with EtOAc and aq. KF. The two phase mixture was stirred for 20 min at rt before being filtered through diatomaceous earth (Celite®). The filtrate was washed with sat. NaHCO3, sat. NaCl, dried over anhydrous Na2SO4, concentrated. The crude product was purified by silica gel chromatography (0-100% EtOAc in hexane) to yield 2-bromo-5-(1-ethoxyvinyl)pyrazine (0.65 g). LC/MS (Cond. N-1): [M+H]+ 229.05, RT=3.799 min.

Workup

  1. filtrationbefore being filtered through diatomaceous earth (Celite®)
  2. washThe filtrate was washed with sat. NaHCO3, sat. NaCl
  3. dry with materialdried over anhydrous Na2SO4
  4. concentrationconcentrated
  5. customThe crude product was purified by silica gel chromatography (0-100% EtOAc in hexane)

Sources & evidence

ORD record
ord-235b84a306454aaea404e22bccc956e7
Source dataset
uspto-grants-2016_05
Patent number
US09326973B2

Reaction notes

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