Pyridine → 6-methoxy-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

HRID 1846292Notes

Reaction equation

HRID 1846292 reaction equation
[NH2:1][C:2]1[CH:10]=[CH:9][C:8]([O:11][CH3:12])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].N1C=CC=CC=1.Cl[C:20](Cl)([O:22]C(=O)OC(Cl)(Cl)Cl)Cl>C(#N)C.ClCCl>[CH3:12][O:11][C:8]1[CH:9]=[CH:10][C:2]2[NH:1][C:20](=[O:22])[O:5][C:4](=[O:6])[C:3]=2[CH:7]=1

Participants

6

Reactant 3

HCID 1049PyridineHCID 94429TriphosgeneHCID 2779305-Methoxyanthranilic acid

Product 1

HCID 2944796-methoxy-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
52.5 °C

Procedure

To a solution of 2-amino-5-methoxy-benzoic acid (1.50 g, 8.97 mmol) in anhydrous acetonitrile (15 mL) at 50-55° C. were simultaneously added pyridine (1.42 g, 17.9 mmol) and a solution of triphosgene (0.870 g, 2.96 mmol) in anhydrous dichloromethane (20 mL) over 20 min span, and the reaction was stirred at 50-55° C. for 2 hours. The solvent was removed and the residue was mixed with water (100 mL), the solid was filtered and rinsed with cold water (30 mL) and dried. The crude was further washed with ether (20 mL) to give 6-methoxy-1H-benzo[d][1,3]oxazine-2,4-dione. Yield: 1.55 g (89%).

Workup

  1. customat 50-55° C.
  2. customThe solvent was removed
  3. additionthe residue was mixed with water (100 mL)
  4. filtrationthe solid was filtered
  5. washrinsed with cold water (30 mL)
  6. customdried
  7. washThe crude was further washed with ether (20 mL)

Sources & evidence

ORD record
ord-920fd3a8e1bc43f494e89e5f1d9170f1
Source dataset
uspto-grants-2015_02
Patent number
US08952021B2

Reaction notes

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