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

HRID 1271139Notes

Reaction equation

HRID 1271139 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-ccc4162a353a4721ab0d609bf5855f22
Source dataset
uspto-grants-2007_04
Patent number
US07205306B2

Reaction notes

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