Water → 5,7-Dimethoxy-2-methyl-4H-benzo[d][1,3]oxazin-4-one

HRID 130327Notes

Reaction equation

HRID 130327 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([NH2:14])[C:6](=[C:10]([O:12][CH3:13])[CH:11]=1)[C:7]([OH:9])=[O:8].[CH2:15](N(CC)CC)[CH3:16].C(OC(=O)C)(=O)C.O>C(Cl)Cl>[CH3:13][O:12][C:10]1[C:6]2[C:7](=[O:9])[O:8][C:15]([CH3:16])=[N:14][C:5]=2[CH:4]=[C:3]([O:2][CH3:1])[CH:11]=1

Participants

6

Reactant 4

HCID 962WaterHCID 7918Acetic AnhydrideHCID 8471TriethylamineHCID 116584562-Amino-4,6-dimethoxybenzoic acid

Product 1

HCID 115068145,7-Dimethoxy-2-methyl-4H-benzo[d][1,3]oxazin-4-oneYield 51%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
40 °C

Procedure

The anthranilic acid (388 mg, 1.97 mmol) prepared in Example 2 was taken up in anhydrous methylene chloride (10 mL). Triethylamine (2.36 mmol) was added followed by addition of acetic anhydride (2.36 mmol). The reaction mixture was heated at 40° C. for 18 hours. Subsequently, the reaction mixture was poured into water and extracted with methylene chloride. The organic layer was washed with saturated aqueous sodium bicarbonate, brine, dried over magnesium sulfate, filtered, and concentrated in vacuo to afford 5,7-dimethoxy-2-methyl-3,1-benzoxazine-4-one (51% yield).

Workup

  1. extractionextracted with methylene chloride
  2. washThe organic layer was washed with saturated aqueous sodium bicarbonate, brine
  3. dry with materialdried over magnesium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-1ebffd0b0898464cab00db3f99018f95
Source dataset
uspto-grants-2008_06
Patent number
US07381730B2

Reaction notes

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