Water → 5,7-dichloro-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

HRID 1639295Notes

Reaction equation

HRID 1639295 reaction equation
[Cl:1][C:2]1[CH:10]=[C:9]([Cl:11])[CH:8]=[C:7]2[C:3]=1[C:4](=[O:13])[C:5](=[O:12])[NH:6]2.[OH2:14]>C(O)(=O)C.[O-2].[O-2].[O-2].[Cr+6]>[Cl:1][C:2]1[C:3]2[C:4](=[O:13])[O:12][C:5](=[O:14])[NH:6][C:7]=2[CH:8]=[C:9]([Cl:11])[CH:10]=1

Participants

5

Reactant 2

HCID 962WaterHCID 2519084,6-Dichloroisatin

Product 1

HCID 123632155,7-dichloro-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

Reagents, catalysts & solvents 2

HCID 10219390chromium (VI) trioxideCatalystHCID 176Acetic AcidSolvent

Procedure

To a suspension of 4,6-dichloroindolin-2,3-dione (5.95 g) in acetic acid (95 ml) was added chromium trioxide (16 g) over a period of 15 minutes at 60° C. with stirring and the mixture was stirred at 70°-75° C. for 1 hour. After cooling, the reaction mixture was poured into water (360 ml) and the resulting precipitates were collected by filtration. The filtrate was extracted with ethyl acetate. The extract was washed with water and dried. Removal of the solvent gave a residue, which was combined with the precipitates. Recrystallization from isopropyl ether gave 5,7-dichloro-2H-3,1-benzoxazine-2,4(1H)-dione (2.85 g).

Workup

  1. stirringthe mixture was stirred at 70°-75° C. for 1 hour
  2. temperatureAfter cooling
  3. customthe resulting precipitates
  4. filtrationwere collected by filtration
  5. extractionThe filtrate was extracted with ethyl acetate
  6. washThe extract was washed with water
  7. customdried
  8. customRemoval of the solvent
  9. customgave a residue, which
  10. customRecrystallization from isopropyl ether

Sources & evidence

ORD record
ord-96b9b44eeffe4de280937446cb0a1355
Source dataset
uspto-grants-1989_11
Patent number
US04883800

Reaction notes

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