2-Aminophenol → Methyl (3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl)acetate

HRID 2259565Notes

Reaction equation

HRID 2259565 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[OH:8].[C:9]1(=[O:15])[O:14][C:12](=[O:13])[CH:11]=[CH:10]1.[CH2:16](N(CC)CC)C>CO>[O:13]=[C:12]1[NH:1][C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=2[O:8][CH:11]1[CH2:10][C:9]([O:14][CH3:16])=[O:15]

Participants

5

Reactant 3

HCID 58012-AminophenolHCID 7923Maleic AnhydrideHCID 8471Triethylamine

Product 1

HCID 4428325Methyl (3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl)acetate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 76.4 g of 2-aminophenol and 68.6 g of maleic anhydride in 1 liter of methanol was stirred at room temperature. After addition of 100 ml of triethylamine, the yellow mass dissolved and the solution was heated for 7 hours at reflux temperature. The methanol was then removed by evaporation under reduced pressure, and the remaining oil was added to ice-water. The mixture was extracted with dichloromethane, and the organic extract was dried over sodium sulfate and evaporated. The remaining residue was crystallized from ethanol. In this way, 47.5 g of methyl (3-oxo-2,3-dihydro-4H-1,4-benzoxazin-2-yl)acetate were obtained as white crystals having a melting point of 140° C.

Workup

  1. dissolutionthe yellow mass dissolved
  2. temperaturethe solution was heated for 7 hours
  3. temperatureat reflux temperature
  4. customThe methanol was then removed by evaporation under reduced pressure
  5. additionthe remaining oil was added to ice-water
  6. extractionThe mixture was extracted with dichloromethane
  7. extractionthe organic extract
  8. dry with materialwas dried over sodium sulfate
  9. customevaporated
  10. customThe remaining residue was crystallized from ethanol

Sources & evidence

ORD record
ord-c850ca0036c84f29b30fdcba2953b59f
Source dataset
uspto-grants-1995_12
Patent number
US05474988

Reaction notes

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