Trimethylaluminum → 1-(1-Ethylpropyl)-5-methyl-3-(methylthio)-2 (1H)-pyrazinone

HRID 2251004Notes

Reaction equation

HRID 2251004 reaction equation
Br[C:2]1[N:3]=[C:4]([S:14][CH3:15])[C:5](=[O:13])[N:6]([CH:8]([CH2:11][CH3:12])[CH2:9][CH3:10])[CH:7]=1.[CH3:16][Al](C)C>C1COCC1.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>[CH2:9]([CH:8]([N:6]1[CH:7]=[C:2]([CH3:16])[N:3]=[C:4]([S:14][CH3:15])[C:5]1=[O:13])[CH2:11][CH3:12])[CH3:10]

Participants

5

Reactant 2

HCID 16682925TrimethylaluminumHCID 588451705-bromo-1-(1-ethylpropyl)-3-(methylthio)-2 (1H)-pyrazinone

Product 1

HCID 588451711-(1-Ethylpropyl)-5-methyl-3-(methylthio)-2 (1H)-pyrazinoneYield 73%

Reagents, catalysts & solvents 2

HCID 178418476HCID 178418476, compoundCatalystHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

A solution of XXXI (2.0 g, 6.9 mmol) and dichlorobis(triphenylphosphine)palladium(II) (484 mg, 0.7 mmol) in THF (40 mL) was treated with trimethylaluminum (6.2 mL, 12.4 mmol, 2M/toluene) dropwise at 0° C. The reaction was refluxed for 4 h, cooled to 0° C. quenched with water (50 mL) and extracted with ethyl acetate (100 mL). The organic phase was dried (MgSO4), filtered, and concentrated in vacuo to give crude residue. Purification by flash column chromatography (silica, ethyl acetate:hexane 1:1) gave the product XXXII (1.14 g, 73%) as a pale yellow solid.

Workup

  1. temperatureThe reaction was refluxed for 4 h
  2. customquenched with water (50 mL)
  3. extractionextracted with ethyl acetate (100 mL)
  4. dry with materialThe organic phase was dried (MgSO4)
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customto give crude residue
  8. customPurification by flash column chromatography (silica, ethyl acetate:hexane 1:1)

Sources & evidence

ORD record
ord-c231cc311fa8401ca9cd6ccdc073b0bb
Source dataset
uspto-grants-2008_01
Patent number
US07319100B2

Reaction notes

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