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

HRID 2205290

Reaktionsgleichung

Reaktionsgleichung von HRID 2205290
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

Komponenten

5

Edukt 3

HCID 136503-HydroxycoumarinHCID 443297Hydroxyamine hydrochlorideHCID 517045Sodium Acetate

Produkt 1

HCID 3017292-(1,2-Benzoxazol-3-yl)acetic acidAusbeute 78,7 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 887MethanolLösungsmittel

Versuchsvorschrift

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%)

Aufarbeitung

  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.

Quellen und Nachweise

ORD-Eintrag
ord-1939e7df48ad4a50bdbf11bb26c7d98e
Quelldatensatz
uspto-grants-2016_06
Patentnummer
US09371282B2

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