Phosgene → 8-methyl-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

HRID 635511Notes

Reaction equation

HRID 635511 reaction equation
[CH3:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:4]([C:5]([OH:7])=[O:6])[C:3]=1[NH2:11].[C:12](Cl)(Cl)=[O:13]>O1CCOCC1.C1(C)C=CC=CC=1>[CH3:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:4]2[C:5]([O:7][C:12](=[O:13])[NH:11][C:3]=12)=[O:6]

Participants

5

Reactant 2

HCID 6371PhosgeneHCID 781012-Amino-3-methylbenzoic acid

Product 1

HCID 27598708-methyl-2,4-dihydro-1H-3,1-benzoxazine-2,4-dioneYield 99.5%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 312751,4-DioxaneSolvent

Procedure

To a mixture of 10.0 g (66.0 mmol) of 3-methylanthranilic acid in 60 mL of 1,4-dioxane was slowly added 100 mL (193 mmol) of a 1.93 molar solution of phosgene in toluene, at room temperature. The mixture was stirred overnight. The mixture was concentrated in vacuo to yield a residue which was triturated with ethyl acetate-hexane (1:4), filtered, washed with hexane and dried to afford 11.66 g (99.5%) of the 3-methylisatoic anhydride as an off white solid. MS (Cl mode) m/z 160 (M-18, 100%), 178 (M+H, 90%).

Workup

  1. customat room temperature
  2. concentrationThe mixture was concentrated in vacuo
  3. customto yield a residue which
  4. customwas triturated with ethyl acetate-hexane (1:4)
  5. filtrationfiltered
  6. washwashed with hexane
  7. customdried

Sources & evidence

ORD record
ord-dc5e2e8a556e4dc189d6cc8b6912aa1d
Source dataset
uspto-grants-2001_02
Patent number
US06187923B1

Reaction notes

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