Water → Ethyl 4-methyl-3-oxoquinoxaline-2-carboxylate

HRID 240337Notes

Reaction equation

HRID 240337 reaction equation
[O:1]=[C:2]1[C:11]([C:12]([O:14][CH2:15][CH3:16])=[O:13])=[N:10][C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[NH:3]1.[H-].[Na+].I[CH3:20].O>CN(C)C=O>[CH3:20][N:3]1[C:4]2[C:9](=[CH:8][CH:7]=[CH:6][CH:5]=2)[N:10]=[C:11]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[C:2]1=[O:1]

Participants

6

Reactant 4

HCID 962WaterHCID 6328Methyl iodideHCID 24758Sodium hydrideHCID 248643Ethyl 3-hydroxyquinoxaline-2-carboxylate

Product 1

HCID 252209Ethyl 4-methyl-3-oxoquinoxaline-2-carboxylateYield 71%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

4.0 g (18.3 mmol) of ethyl 2-oxo-1,2-dihydroquinoxaline-3-carboxylate was dissolved in N,N-dimethylformamide (100 mL), and under a nitrogen stream, 0.81 g (20.3 mmol) of 60% sodium hydride (oily) was added thereto, while maintaining the liquid temperature in the range of 5° C. to 10° C. After stirring the mixture for one hour at room temperature, 3.9 g (27.5 mmol) of iodomethane was added dropwise to the reaction solution. The mixture was stirred for a day at room temperature, and then the reaction mixture was poured into water, and extracted with ethyl acetate. The organic layer was washed with water and a saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate. The inorganic matter was separated by filtration, and then the solvent was distilled off under reduced pressure. The residue thus obtained was purified by silica gel chromatography (developing solvent: ethyl acetate:hexane=3:2), to obtain 3.0 g (yield: 71%) of ethyl 1-methyl-2-oxo-1,2-dihydroquinoxaline-3-carboxylate as a white powder.

Workup

  1. temperaturewhile maintaining the liquid temperature in the range of 5° C. to 10° C
  2. stirringThe mixture was stirred for a day at room temperature
  3. extractionextracted with ethyl acetate
  4. washThe organic layer was washed with water
  5. dry with materiala saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate
  6. customThe inorganic matter was separated by filtration
  7. distillationthe solvent was distilled off under reduced pressure
  8. customThe residue thus obtained
  9. customwas purified by silica gel chromatography (developing solvent: ethyl acetate:hexane=3:2)

Sources & evidence

ORD record
ord-8248e52247a3496e908757fe88a9ae37
Source dataset
uspto-grants-2014_02
Patent number
US08648075B2

Reaction notes

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