Phosgene → 6-Fluoro-1,3-benzoxazol-2(3H)-one

HRID 275449Notes

Reaction equation

HRID 275449 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([F:8])=[CH:4][C:3]=1[OH:9].[C:10](=O)([O-])[O-:11].[K+].[K+].C(Cl)(Cl)=O>C(Cl)Cl.C1(C)C=CC=CC=1>[F:8][C:5]1[CH:6]=[CH:7][C:2]2[NH:1][C:10](=[O:11])[O:9][C:3]=2[CH:4]=1

Participants

6

Reactant 3

HCID 6371PhosgeneHCID 11430Potassium CarbonateHCID 1857632-Amino-5-fluorophenol

Product 1

HCID 144573586-Fluoro-1,3-benzoxazol-2(3H)-oneYield 96%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 6344DichloromethaneSolvent

Procedure

To 5.0 g (39.3 mmol) 2-amino-5-fluorophenol in 150 ml of CH2Cl2 at 0° C. was added 13.4 (98 mmol) of potassium carbonate and 23 g (47 mmol) of 20 wt. % phosgene in toluene. After warming to room temperature, the reaction was stirred an additional hour before quenching onto 200 ml ice/water. The layers were separated and the aqueous phase was extracted with EtOAc (1×100 ml) before the organics were combined and dried over Na2SO4. The solvent was removed in vacuo to give 5.76 g (96% yield) of the desired product as determined by 1H NMR.

Workup

  1. custombefore quenching onto 200 ml ice/water
  2. customThe layers were separated
  3. extractionthe aqueous phase was extracted with EtOAc (1×100 ml) before the
  4. dry with materialdried over Na2SO4
  5. customThe solvent was removed in vacuo

Sources & evidence

ORD record
ord-c0d0f216f7a4464b823006ecd68e6c7a
Source dataset
uspto-grants-1995_02
Patent number
US05393735

Reaction notes

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