4-Pentynoic acid ethyl ester → Ethyl 5-(pyridin-2-yl)pent-4-ynoate

HRID 334536Notes

Reaction equation

HRID 334536 reaction equation
I[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=1.[C:8]([O:14][CH2:15][CH3:16])(=[O:13])[CH2:9][CH2:10][C:11]#[CH:12]>C(N(CC)CC)C.[Cu](I)I.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>[N:3]1[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=1[C:12]#[C:11][CH2:10][CH2:9][C:8]([O:14][CH2:15][CH3:16])=[O:13]

Participants

6

Reactant 2

HCID 1439504-Pentynoic acid ethyl esterHCID 2211262-Iodopyridine

Product 1

HCID 66598348Ethyl 5-(pyridin-2-yl)pent-4-ynoateYield 91.4%

Reagents, catalysts & solvents 3

HCID 83717Copper iodideCatalystHCID 178418476HCID 178418476, compoundCatalystHCID 8471TriethylamineSolvent2×

Procedure

In a dry reaction tube containing in suspension copper iodide (60 mg, 0.315 mmol) and triethylamine (17.70 mL, 126 mmol), were added 2-iodopyridine (1.29 g, 6.30 mmol) and the Pd(PPh3)2Cl2 (202 mg, 0.315 mmol). A yellow suspension is obtained and after a few minutes of stirring at room temperature, was added ethyl pent-4-ynoate (790 mg, 6.30 mmol) in solution in 2 mL of triethylamine. Immediately the color of the reaction turns to black. The mixture was stirred at room temperature for 30 min and then at 80° C. for 20 h. Triethylamine was concentrated under reduce pressure and the residue was dissolved in DCM. The organic layer was washed with saturated NH4Cl, water and brine. The solvent was removed under reduced pressure and the crude product was purified by flash chromatography system (prepacked silicagel column 25 g, DCM/MeOH: 98/2 as eluent) to afford 1.17 g of ethyl 5-(pyridin-2-yl)pent-4-ynoate (Yield: 78%) as brownish oil.

Workup

  1. customIn a dry reaction tube
  2. customA yellow suspension is obtained and after a few minutes
  3. stirringThe mixture was stirred at room temperature for 30 min
  4. concentrationTriethylamine was concentrated
  5. dissolutionthe residue was dissolved in DCM
  6. washThe organic layer was washed with saturated NH4Cl, water and brine
  7. customThe solvent was removed under reduced pressure
  8. customthe crude product was purified by flash chromatography system (prepacked silicagel column 25 g, DCM/MeOH: 98/2 as eluent)

Sources & evidence

ORD record
ord-ee23fc1f27bb4cc895f3266fe127d364
Source dataset
uspto-grants-2014_11
Patent number
US08883826B2

Reaction notes

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