Pyridine → 6-methoxy-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione
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]=1Participants
6
Reactant 3
Product 1
Reagents, catalysts & solvents 2
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 minute 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 product was further washed with ether (20 mL) to give 6-methoxy-1H-benzo[d][1,3]oxazine-2,4-dione. Yield: 1.40 g (81%).
Workup
- customat 50-55° C.
- customThe solvent was removed
- additionthe residue was mixed with water (100 mL)
- filtrationthe solid was filtered
- washrinsed with cold water (30 mL)
- customdried
- washThe crude product was further washed with ether (20 mL)
Sources & evidence
- ORD record
- ord-8fdf3c47ad56414ab6f1b43728ab647d
- Source dataset
- uspto-grants-2015_02
- Patent number
- US08952021B2
Reaction notes
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