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

HRID 569807

Reaction equation

HRID 569807 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-96b79913e52e4204b7065cc2cf9372a3
Source dataset
uspto-grants-1988_03
Patent number
US04734419

Linked notes

Loading…