Pyridine → 7-Fluoroisatoic anhydride

HRID 1846265Notes

Reaction equation

HRID 1846265 reaction equation
[NH2:1][C:2]1[CH:10]=[C:9]([F:11])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].N1C=CC=CC=1.Cl[C:19](Cl)([O:21]C(=O)OC(Cl)(Cl)Cl)Cl>C(#N)C.C(Cl)Cl>[F:11][C:9]1[CH:8]=[CH:7][C:3]2[C:4](=[O:6])[O:5][C:19](=[O:21])[NH:1][C:2]=2[CH:10]=1

Participants

6

Reactant 3

HCID 1049PyridineHCID 94429TriphosgeneHCID 27249674-Fluoroanthranilic acid

Product 1

HCID 100581387-Fluoroisatoic anhydride

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
55 °C

Procedure

To a stirred solution of 2-amino-4-fluoro benzoic acid (L) (1.15 g, 7.40 mmol) in anhydrous acetonitrile (8 mL) at 55° C. were simultaneously added anhydrous pyridine (1.2 mL, 15 mmol) and a solution of triphosgene (0.73 g, 2.5 mmol) in anhydrous CH2Cl2 (5 mL) via syringe over a period of 15-20 minutes. After the addition was completed, the reaction mixture was stirred at 55° C. for another 2 hours. Much solid precipitated out. The solvent was distilled off. After cooling down to room temperature, water was added and the solid was filtered off, washed with water, followed by chilled CH2Cl2. The solid was dried under vacuum to give 7-fluoro-1H-benzo[d][1,3]oxazine-2,4-dione (M) as grayish solid. Yield: 1.02 g (76%).

Workup

  1. customat 55° C.
  2. additionAfter the addition
  3. customMuch solid precipitated out
  4. distillationThe solvent was distilled off
  5. temperatureAfter cooling down to room temperature
  6. additionwater was added
  7. filtrationthe solid was filtered off
  8. washwashed with water
  9. temperatureby chilled CH2Cl2
  10. customThe solid was dried under vacuum

Sources & evidence

ORD record
ord-6cd8817d6abc4fe7bf163b40b8da0d80
Source dataset
uspto-grants-2015_02
Patent number
US08952021B2

Reaction notes

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