Potassium Carbonate → 7-Methoxy-2H-1,4-benzoxazin-3(4H)-one

HRID 279935Notes

Reaction equation

HRID 279935 reaction equation
Cl[CH2:2][C:3]([NH:5][C:6]1[CH:11]=[CH:10][C:9]([O:12][CH3:13])=[CH:8][C:7]=1[OH:14])=[O:4].C(=O)([O-])[O-].[K+].[K+]>CC(C)=O>[CH3:13][O:12][C:9]1[CH:10]=[CH:11][C:6]2[NH:5][C:3](=[O:4])[CH2:2][O:14][C:7]=2[CH:8]=1

Participants

4

Reactant 2

HCID 11430Potassium CarbonateHCID 135065532-Chloroacetamido-5-methoxy phenol

Product 1

HCID 116007707-Methoxy-2H-1,4-benzoxazin-3(4H)-oneYield 86%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

A reaction mixture was prepared from 19.6 g of N-chloroacetyl-2-hydroxy-4-methoxyaniline, 13.8 g of potassium carbonate and 500 ml of acetone. The mixture was refluxed with stirring for about 5 hours and was then cooled. Inorganic salts were separated by filtration, and the solvent removed from the filtrate in vacuo. The resulting residue was dissolved in methylenedichloride. The methylenedichloride solution was washed with saturated aqueous sodium chloride and then dried. Fourteen grams of 3,4-dihydro-7-methoxy-2H-[1,4]benzoxazin-3-one were obtained. NMR indicated complete cyclization to the lactam. Recrystallization from ethyl acetate/hexane yielded product melting at 164°-165° C.

Workup

  1. temperatureThe mixture was refluxed
  2. temperaturewas then cooled
  3. customInorganic salts were separated by filtration
  4. customthe solvent removed from the filtrate in vacuo
  5. dissolutionThe resulting residue was dissolved in methylenedichloride
  6. washThe methylenedichloride solution was washed with saturated aqueous sodium chloride
  7. customdried

Sources & evidence

ORD record
ord-ead9f17990414c19a2fc824a9b5f0d0c
Source dataset
uspto-grants-1986_05
Patent number
US04587336

Reaction notes

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