Cesium carbonate → Methyl 6-(2-furanyl)-2-pyrazinecarboxylate

HRID 1510720Notes

Reaction equation

HRID 1510720 reaction equation
Cl[C:2]1[N:7]=[C:6]([C:8]([O:10][CH3:11])=[O:9])[CH:5]=[N:4][CH:3]=1.[O:12]1[CH:16]=[CH:15][CH:14]=[C:13]1B(O)O.[Cl-].[Li+].C(=O)([O-])[O-].[Cs+].[Cs+].C1(P(C2CCCCC2)C2C=CC=CC=2C2C(OC)=CC=CC=2OC)CCCCC1>O1CCOCC1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd].C(OCC)(=O)C.O>[O:12]1[CH:16]=[CH:15][CH:14]=[C:13]1[C:2]1[N:7]=[C:6]([C:8]([O:10][CH3:11])=[O:9])[CH:5]=[N:4][CH:3]=1

Participants

10

Reactant 5

HCID 10796Cesium carbonateHCID 433294Lithium ChlorideHCID 2734357Furan-2-boronic acidHCID 11084353Methyl 6-chloropyrazine-2-carboxylateHCID 112698722-Dicyclohexylphosphino-2',6'-dimethoxybiphenyl

Product 1

HCID 57815221Methyl 6-(2-furanyl)-2-pyrazinecarboxylateYield 62.5%

Reagents, catalysts & solvents 4

HCID 9811564Bis(dibenzylideneacetone)palladiumCatalystHCID 962WaterSolventHCID 8857Ethyl AcetateSolventHCID 312751,4-DioxaneSolvent

Procedure

To a solution of 0.10 g of methyl 6-chloropyrazine-2-carboxylate in 2.9 mL of dioxane, 65 mg of 2-furanboronic acid, 74 mg of lithium chloride, 0.57 g of cesium carbonate, 21 mg of 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl and 24 mg of tris(dibenzylideneacetone)dipalladium(0) were added, and the mixture was heated under reflux for 2 hours. To the reaction mixture, water and ethyl acetate were added, the organic layer was separated, washed with a saturated aqueous sodium chloride solution and dried over anhydrous magnesium sulfate, and the solvent was then distilled off under reduced pressure. The resultant residue was purified by flash silica gel column chromatography using gradient elution with hexane:ethyl acetate=87:13 to 83:17 to obtain 74 mg of methyl 6-(2-furyl)pyrazine-2-carboxylate as a white solid.

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux for 2 hours
  3. customthe organic layer was separated
  4. washwashed with a saturated aqueous sodium chloride solution
  5. dry with materialdried over anhydrous magnesium sulfate
  6. distillationthe solvent was then distilled off under reduced pressure
  7. customThe resultant residue was purified by flash silica gel column chromatography
  8. washelution with hexane

Sources & evidence

ORD record
ord-d5cdd0b233b549918d922437e115d1c7
Source dataset
uspto-grants-2012_07
Patent number
US08211908B2

Reaction notes

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