3-Hydroxycoumarin → 2-(1,2-Benzoxazol-3-yl)acetic acid

HRID 2205290

Reaction equation

HRID 2205290 reaction equation
Cl.[NH2:2][OH:3].O[C:5]1[C:6](=[O:15])[O:7][C:8]2[C:13]([CH:14]=1)=[CH:12][CH:11]=[CH:10][CH:9]=2.C([O-])(=O)C.[Na+]>CO>[O:3]1[C:12]2[CH:11]=[CH:10][CH:9]=[CH:8][C:13]=2[C:14]([CH2:5][C:6]([OH:15])=[O:7])=[N:2]1

Participants

5

Reactant 3

HCID 136503-HydroxycoumarinHCID 443297Hydroxyamine hydrochlorideHCID 517045Sodium Acetate

Product 1

HCID 3017292-(1,2-Benzoxazol-3-yl)acetic acidYield 78.7%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Hydroxylamine hydrochloride (7.5 g, 107.93 mmol) is added to a solution of hydroxy coumarin (5 g, 30.84 mmol) in MeOH (50 mL) at rt. Sodium acetate (8.8 g, 107.93 mmol) is added portionwise in 1.5 h. The reaction is stirred for 1.5 h at rt and then is heated at reflux overnight. Volatiles are evaporated, water is added and the mixture is cooled with ice-water bath. The aqueous layer is acidified to pH=3 with 4N HCl. A precipitate is filtered out and washed several times with water. The precipitate is dried under reduce pressure at 50° C. to give benzo[d]isoxazol-3-yl-acetic acid (4.3 g, 78%)

Workup

  1. temperatureis heated
  2. temperatureat reflux overnight
  3. customVolatiles are evaporated
  4. additionwater is added
  5. temperaturethe mixture is cooled with ice-water bath
  6. filtrationA precipitate is filtered out
  7. washwashed several times with water
  8. customThe precipitate is dried
  9. customat 50° C.

Sources & evidence

ORD record
ord-1939e7df48ad4a50bdbf11bb26c7d98e
Source dataset
uspto-grants-2016_06
Patent number
US09371282B2

Linked notes

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