Methanol → 5-Phenyl-3-isoxazolecarboxylic acid

HRID 1093581Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1093581
C[O:2][C:3]([C:5]1[CH:9]=[C:8]([C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=2)[O:7][N:6]=1)=[O:4].CO.O.O[Li].O>C1COCC1>[C:10]1([C:8]2[O:7][N:6]=[C:5]([C:3]([OH:4])=[O:2])[CH:9]=2)[CH:11]=[CH:12][CH:13]=[CH:14][CH:15]=1

Komponenten

6

Edukt 4

HCID 887MethanolHCID 962WaterHCID 168937Lithium hydroxide, monohydrateHCID 905953Methyl 5-phenyl-1,2-oxazole-3-carboxylate

Produkt 1

HCID 1519165-Phenyl-3-isoxazolecarboxylic acidAusbeute 85 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Versuchsvorschrift

To a stirred solution of 2,4-dioxo-4-phenyl-butyric acid ethyl ester (3.86 g, 0.01754 mole) in methanol (78 mL) was added hydroxylamine hydrochloride (3.657 g, 0.0526 mole) at ambient temperature. The resulting mixture was then heated to reflux overnight. Volatiles were then removed by evaporation and the resulting residue was diluted with water and the product extracted with chloroform. The chloroform layer was collected and washed with brine solution, dried over sodium sulfate and concentrated under reduced pressure. The resulting residue was purified by column chromatography using silica gel 60-120 mesh (4% ethyl acetate in hexane) to afford 2.8 g (79%) of 5-phenyl-isoxazole-3-carboxylic acid methyl ester. LCMS: 204.06 (M+1)+, 97.58%. To a stirred solution of 5-phenyl-isoxazole-3-carboxylic acid methyl ester (2.8 g, 0.01379 mol) in a mixture of THF (10 mL), methanol (10 mL) and H2O (10 mL) was added LiOH.H2O (0.87 g, 0.02073 mol) and the resulting mixture was stirred at ambient temperature for 2.5 hours. Volatiles were then evaporated and the resulting residue was diluted with water, acidified with concentrated HCl and extracted with ethyl acetate. The ethyl acetate layer was collected and washed with brine solution, dried over sodium sulfate and concentrated under reduced pressure to afford 2.2 g (85%) of 5-phenyl-isoxazole-3-carboxylic acid. LCMS: 190.04 (M+1)+, 96.4%.

Aufarbeitung

  1. customVolatiles were then evaporated
  2. additionthe resulting residue was diluted with water
  3. extractionextracted with ethyl acetate
  4. customThe ethyl acetate layer was collected
  5. washwashed with brine solution
  6. dry with materialdried over sodium sulfate
  7. concentrationconcentrated under reduced pressure

Quellen und Nachweise

ORD-Eintrag
ord-a4853cb65d344556b6fe8d9a6cdb804e
Quelldatensatz
uspto-grants-2012_03
Patentnummer
US08129376B2

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