Hydroxyamine hydrochloride → 2-(6-Bromo-1,2-benzoxazol-3-yl)acetic acid

HRID 1988890Notes

Reaction equation

HRID 1988890 reaction equation
[Na].Cl.[NH2:3][OH:4].[Br:5][C:6]1[CH:15]=[C:14]2[C:9]([C:10](O)=[CH:11][C:12](=[O:16])[O:13]2)=[CH:8][CH:7]=1.C(=O)(O)[O-].[Na+]>C(O)C.ClCCl.O>[Br:5][C:6]1[CH:7]=[CH:8][C:9]2[C:10]([CH2:11][C:12]([OH:16])=[O:13])=[N:3][O:4][C:14]=2[CH:15]=1

Participants

8

Reactant 4

HCID 443297Hydroxyamine hydrochlorideHCID 516892Sodium BicarbonateHCID 5360545SodiumHCID 546962297-Bromo-4-hydroxycoumarin2×

Product 1

HCID 591273762-(6-Bromo-1,2-benzoxazol-3-yl)acetic acidYield 76.8%

Reagents, catalysts & solvents 3

HCID 702EthanolSolvent2×HCID 962WaterSolventHCID 6344DichloromethaneSolvent

Procedure

Sodium metal (0.36 g) was dissolved in dry ethanol (30 ml) then treated with hydroxylamine hydrochloride (1.12 g). A solution of 7-bromo-4-hydroxy-2H-chromen-2-one (Intermediate 31) (1.3 g) in dry ethanol (30 ml) was added and the mixture was stirred at reflux under nitrogen for 3.5 h. On cooling the mixture was added to 2M aqueous sodium bicarbonate (100 ml). Water (100 ml) and dichloromethane (100 ml) were added, the phases were separated and the aqueous layer was washed with more dichloromethane (75 ml). The aqueous layer was acidified by the cautious addition of 2N hydrochloric acid to yield a precipitate which was collected by filtration and dried to give the title compound as a white solid (1.06 g).

Workup

  1. temperatureat reflux under nitrogen for 3.5 h
  2. temperatureOn cooling the mixture
  3. customthe phases were separated
  4. washthe aqueous layer was washed with more dichloromethane (75 ml)
  5. additionThe aqueous layer was acidified by the cautious addition of 2N hydrochloric acid
  6. customto yield a precipitate which
  7. filtrationwas collected by filtration
  8. customdried

Sources & evidence

ORD record
ord-fcc71233e32c490bacd2ec98429cdf32
Source dataset
uspto-grants-2010_01
Patent number
US07642276B2

Reaction notes

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