Ammonium fluoride → Ethyl 3-(4-pyridyl)furan-2-carboxylate

HRID 1967876Notes

Reaction equation

HRID 1967876 reaction equation
Br[C:2]1[CH:6]=[CH:5][O:4][C:3]=1[C:7]([O:9][CH2:10][CH3:11])=[O:8].C([Sn](CCCC)(CCCC)[C:17]1[CH:22]=[CH:21][N:20]=[CH:19][CH:18]=1)CCC.[F-].[NH4+]>C1COCC1.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[N:20]1[CH:21]=[CH:22][C:17]([C:2]2[CH:6]=[CH:5][O:4][C:3]=2[C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:18][CH:19]=1

Participants

6

Reactant 3

HCID 25516Ammonium fluorideHCID 27373184-(Tri-n-butylstannyl)pyridineHCID 22456149Ethyl 3-bromofuran-2-carboxylate

Product 1

HCID 23144513Ethyl 3-(4-pyridyl)furan-2-carboxylateYield 45.4%

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 8028TetrahydrofuranSolvent

Procedure

Ethyl 3-bromofuran-2-carboxylate (296 mg, 1.35 mmol) obtained in Step 1 of Reference Example 29, 4-(tri-n-butylstannyl)pyridine (550 mg, 1.51 mmol) and tetrakis(triphenylphosphine)palladium(0) (157 mg, 0.136 mmol) were dissolved in THF (10 mL), followed by stirring under heating and reflux for 4 hours. Aqueous ammonium fluoride solution was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and then the solvent was distilled away under reduced pressure. The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3) to afford ethyl 3-(4-pyridyl)furan-2-carboxylate (133 mg, 45%).

Workup

  1. temperatureunder heating
  2. temperaturereflux for 4 hours
  3. extractionfollowed by extraction with ethyl acetate
  4. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
  5. distillationthe solvent was distilled away under reduced pressure
  6. customThe resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3)

Sources & evidence

ORD record
ord-b2c9eda1d00b4d95a2e9dcd1b51acfed
Source dataset
uspto-grants-2013_04
Patent number
US08420827B2

Reaction notes

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