Phosgene → 5-Methoxy-2H-3,1-benzoxazine-2,4(1H)-dione

HRID 1725958Notes

Reaction equation

HRID 1725958 reaction equation
[OH-].[Na+].[NH2:3][C:4]1[CH:12]=[CH:11][CH:10]=[C:9]([O:13][CH3:14])[C:5]=1[C:6]([OH:8])=[O:7].[C:15](Cl)(Cl)=[O:16]>O.C1(C)C=CC=CC=1>[CH3:14][O:13][C:9]1[C:5]2[C:6](=[O:8])[O:7][C:15](=[O:16])[NH:3][C:4]=2[CH:12]=[CH:11][CH:10]=1

Participants

6

Reactant 3

HCID 6371PhosgeneHCID 14798Sodium HydroxideHCID 27353572-Amino-6-methoxybenzoic Acid

Product 1

HCID 107502955-Methoxy-2H-3,1-benzoxazine-2,4(1H)-dioneYield 91%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 1140TolueneSolvent

Conditions

Temperature
0 °C

Procedure

A solution of NaOH (6.6 g, 165 mmol) in water (300 mL) was treated with 2-amino-6-methoxylbenzoic acid (10 g, 59.9 mmol); cooled to 0° C., treated dropwise with a 20% wt solution of phosgene in toluene (75 mL), stirred overnight at room temperature and filtered. The filter cake provided 10.5 g of the desired product (yield: 91.0%). 1H NMR (DMSO-d6) δ 3.85 (s, 3H), 6.65 (d, 1H), 6.80 (d, 1H), 7.65 (t, 1H), 11.58 (br s, 1H); MS (ESI(−) m/e 192 (M−H)−.

Workup

  1. filtrationfiltered

Sources & evidence

ORD record
ord-01f2fe81a6254e76acdf9748825ce65f
Source dataset
uspto-grants-2009_02
Patent number
US07491718B2

Reaction notes

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