Hydrochloric Acid → 2-(6,7-Dichloro-3-oxo-2H-benzo[b][1,4]oxazin-4(3H)-yl)acetic acid

HRID 2114451Notes

Reaction equation

HRID 2114451 reaction equation
[Cl:1][C:2]1[C:3]([Cl:19])=[CH:4][C:5]2[O:10][CH2:9][C:8](=[O:11])[N:7]([CH2:12][C:13]([O:15]CC)=[O:14])[C:6]=2[CH:18]=1.[Li+].[OH-].O.Cl>C1COCC1.C(O)(=O)C>[Cl:1][C:2]1[C:3]([Cl:19])=[CH:4][C:5]2[O:10][CH2:9][C:8](=[O:11])[N:7]([CH2:12][C:13]([OH:15])=[O:14])[C:6]=2[CH:18]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 962WaterHCID 3939Lithium HydroxideHCID 57488847Ethyl(6,7-dichloro-3-oxo-2,3-dihydro-4H-1,4-benzoxazin-4-yl)acetate

Product 1

HCID 574888462-(6,7-Dichloro-3-oxo-2H-benzo[b][1,4]oxazin-4(3H)-yl)acetic acid

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 8028TetrahydrofuranSolvent

Procedure

Ethyl (6,7-dichloro-3-oxo-2,3-dihydro-4H-1,4-benzoxazin-4-yl)acetate (52.6 g, 0.173 mol) and LiOH (8.31 g, 0.347 mol) were combined in 750 mL of THF and 150 mL of water and stirred at room temperature for 18 hours, after which time HPLC indicated loss of the starting material. 80 mL of concentrated HCl was added and the mixture was stirred for 1 hour, and then evaporated to dryness. The residue was dissolved in EtOAc and water was added. The layers were separated and the organic layer was washed with water (2×). The organic layer was dried over magnesium sulphate and concentrated to give 45.5 g (0.165 mol, 95%) of 6,7-dichloro-3-oxo-2,3-dihydro-4H-1,4-benzoxazin-4-yl)acetic acid. MS (ES) m/e 278 [M+H]+.

Workup

  1. customevaporated to dryness
  2. dissolutionThe residue was dissolved in EtOAc
  3. additionwater was added
  4. customThe layers were separated
  5. washthe organic layer was washed with water (2×)
  6. dry with materialThe organic layer was dried over magnesium sulphate
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-89750718c93943e9903da423d0a3bf5f
Source dataset
uspto-grants-2008_10
Patent number
US07432258B2

Reaction notes

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