Diethyl Ether → 3-tert-Butoxy-5-fluoropyrazine-2-carboxaldehyde

HRID 890057Notes

Reaction equation

HRID 890057 reaction equation
[C:1]([O:5][C:6]1[C:7]([CH:13]=[O:14])=[N:8][CH:9]=[C:10](Cl)[N:11]=1)([CH3:4])([CH3:3])[CH3:2].[F-:15].[K+].C1OCCOCCOCCOCCOCCOC1.C(OCC)C>C(#N)C.[Br-].C1([P+](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>[C:1]([O:5][C:6]1[C:7]([CH:13]=[O:14])=[N:8][CH:9]=[C:10]([F:15])[N:11]=1)([CH3:4])([CH3:3])[CH3:2]

Participants

7

Reactant 4

HCID 3283Diethyl EtherHCID 2855718-Crown-6HCID 522689Potassium FluorideHCID 222482023-Tert-butoxy-5-chloropyrazine-2-carboxaldehyde

Product 1

HCID 222482523-tert-Butoxy-5-fluoropyrazine-2-carboxaldehydeYield 3.4%

Reagents, catalysts & solvents 2

HCID 2724163Tetraphenylphosphonium BromideCatalystHCID 6342AcetonitrileSolvent

Procedure

After dissolving 5.86 g of the crude 3-tert-butoxy-5-chloropyrazine-2-carboxaldehyde in 55 ml of acetonitrile, 4.77 g of potassium fluoride, 1.13 g of tetraphenylphosphonium bromide and 0.71 g of 18-crown-6 were added and the mixture was heated to reflux for 4 hours. Diethyl ether was added to the reaction mixture, the insoluble portion was filtered out, and the filtrate was distilled off under reduced pressure. Ethyl acetate was added to the residue, the insoluble portion was filtered out, and the filtrate was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (solvent: toluene/ethyl acetate) to obtain the title compound (183 mg, 3% yield).

Workup

  1. additionwere added
  2. temperaturethe mixture was heated
  3. temperatureto reflux for 4 hours
  4. filtrationthe insoluble portion was filtered out
  5. distillationthe filtrate was distilled off under reduced pressure
  6. additionEthyl acetate was added to the residue
  7. filtrationthe insoluble portion was filtered out
  8. distillationthe filtrate was distilled off under reduced pressure
  9. customThe residue was purified by silica gel column chromatography (solvent: toluene/ethyl acetate)

Sources & evidence

ORD record
ord-5bb49986b50d4aa78b351e6e7763ddc7
Source dataset
uspto-grants-2006_02
Patent number
US06995144B2

Reaction notes

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