Ethyl Acetate → 2-(Pyrazin-2-yl)but-3-yn-2-ol

HRID 1260585Notes

Reaction equation

HRID 1260585 reaction equation
[C:1]([Mg]Cl)#[CH:2].[N:5]1[CH:10]=[CH:9][N:8]=[CH:7][C:6]=1[C:11](=[O:13])[CH3:12].C(OCC)(=O)C>O1CCCC1>[N:5]1[CH:10]=[CH:9][N:8]=[CH:7][C:6]=1[C:11]([OH:13])([C:1]#[CH:2])[CH3:12]

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 30914AcetylpyrazineHCID 178462451HCID 178462451, compound

Product 1

HCID 582214102-(Pyrazin-2-yl)but-3-yn-2-ol

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

A 0.5 M solution of ethynylmagnesium chloride in tetrahydrofuran (31.90 mmol, Aldrich) is diluted with 50 ml of tetrahydrofuran and then cooled to 0° C. 3 g of 1-pyrazin-2-ylethanone (24.56 mmol, Lancaster) are then added in several fractions, and the mixture is stirred at 0° C. for 4 hours. The mixture is cooled once again with an ice bath and a solution of NH4Claq is added slowly. The mixture is extracted twice with ethyl acetate and the organic phases are then combined, dried over sodium sulphate, filtered, and concentrated under vacuum. The oily residue obtained is purified by silica chromatography (elution with a cyclohexane:ethyl acetate gradient, 70:30 to 50:50) and 2.9 g of the expected product are obtained in the form of a yellow oil (yield=80%).

Workup

  1. temperatureThe mixture is cooled once again with an ice bath
  2. additiona solution of NH4Claq is added slowly
  3. extractionThe mixture is extracted twice with ethyl acetate
  4. dry with materialdried over sodium sulphate
  5. filtrationfiltered
  6. concentrationconcentrated under vacuum
  7. customThe oily residue obtained
  8. customis purified by silica chromatography (
  9. washelution with a cyclohexane

Sources & evidence

ORD record
ord-302e4674f22a495eb0a6f54675d7fbec
Source dataset
uspto-grants-2013_06
Patent number
US08470847B2

Reaction notes

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