Acetic Anhydride → 5-Fluoroisatoic anhydride

HRID 343889Notes

Reaction equation

HRID 343889 reaction equation
[C:1]([O:4][C:5](=[O:7])[CH3:6])(=[O:3])C.[F:8][C:9]1[CH:10]=C2[C:15](=[CH:16][CH:17]=1)[NH:14]C(=O)C2=O>[O-2].[Cr+6].[O-2].[O-2].C(O)(=O)C>[F:8][C:9]1[CH:10]=[C:6]2[C:5]([O:4][C:1](=[O:3])[NH:14][C:15]2=[CH:16][CH:17]=1)=[O:7]

Participants

5

Reactant 2

HCID 7918Acetic AnhydrideHCID 2365665-Fluoroisatin

Product 1

HCID 2885605-Fluoroisatoic anhydride

Reagents, catalysts & solvents 2

HCID 10219390chromium (VI) trioxideCatalystHCID 176Acetic AcidSolvent

Conditions

Temperature
85 °C

Procedure

Acetic anhydride (90.0 mL), 5-fluoroisatin (20.62 g, 0.125 mmol, 1.00 eq), and acetic acid (90 mL) were added to a 250 mL, three neck flask fitted with a magnetic stir bar and a condenser. The flask was placed in a water bath and heated to 85° C. Chromium (VI) oxide (20.36 g, 0.204 mol, 1.63 eq) was added in small portions (0.5 g size) over 40 min to the red solution. The reaction mixture was stirred for an additional 15 min and cooled to 10° C. in an ice bath. The solid that formed was isolated by filtration. Washing with 400 mL of water removed most of the green color. The solid was taken up in 300 mL of 2:1 acetic acid/water, refiltered, and dried overnight in a 50° C. vacuum oven. The 5-fluoroisatoic anhydride was isolated as a bright yellow solid (14.45 g, 64%). ##STR5##

Workup

  1. customfitted with a magnetic stir bar and a condenser
  2. customThe flask was placed in a water bath
  3. temperaturecooled to 10° C. in an ice bath
  4. customThe solid that formed
  5. customwas isolated by filtration
  6. washWashing with 400 mL of water
  7. customremoved most of the green color
  8. customdried overnight in a 50° C. vacuum oven

Sources & evidence

ORD record
ord-c395c46c63fe4ebdb2001fed07ff1352
Source dataset
uspto-grants-1999_01
Patent number
US05863944

Reaction notes

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