Triethylamine → 5-Methoxy-2-(methylamino)-4H-3,1-benzoxazin-4-one

HRID 598069Notes

Reaction equation

HRID 598069 reaction equation
[NH2:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:7]([O:11][CH3:12])[C:3]=1[C:4]([OH:6])=[O:5].[CH3:13][N:14]=[C:15]=O.Cl.CN(C)CCCN=C=NCC.C(N(CC)CC)C>O1CCOCC1.O>[CH3:12][O:11][C:7]1[C:3]2[C:4](=[O:6])[O:5][C:13]([NH:14][CH3:15])=[N:1][C:2]=2[CH:10]=[CH:9][CH:8]=1

Participants

7

Reactant 4

HCID 8471TriethylamineHCID 12228Methyl IsocyanateHCID 27239391,3-Propanediamine, N'-(ethylcarbonimidoyl)-N,N-dimethyl-, monohydrochlorideHCID 27353572-Amino-6-methoxybenzoic Acid

Product 1

HCID 672673385-Methoxy-2-(methylamino)-4H-3,1-benzoxazin-4-oneYield 43%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Conditions

Temperature
80 °C

Procedure

A mixture of 2-amino-6-methoxybenzoic acid (2.00 g, 12.0 mmol) and methylisocyanate (1.00 g, 17.5 mmol) in dioxane (50 ml) was stirred at 80° C. for 2 h. After cooling to room temperature, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (6.88 g, 36.0 mmol) and triethylamine (5.00 ml, 36.0 mmol) were added. The mixture was stirred at room temperature for 16 h, diluted with water and extracted with ethyl acetate. The extract was washed with brine, dried over magnesium sulfate and concentrated under vacuum. The residue was purified by column chromatography eluting with 20% ethyl acetate/n-hexane to afford 1.06 g (43%) of the title compound.

Workup

  1. temperatureAfter cooling to room temperature
  2. stirringThe mixture was stirred at room temperature for 16 h
  3. extractionextracted with ethyl acetate
  4. washThe extract was washed with brine
  5. dry with materialdried over magnesium sulfate
  6. concentrationconcentrated under vacuum
  7. customThe residue was purified by column chromatography
  8. washeluting with 20% ethyl acetate/n-hexane

Sources & evidence

ORD record
ord-0c9d21e66dd648f997dd41525663635f
Source dataset
uspto-grants-2011_03
Patent number
US07897607B2

Reaction notes

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