tert-Butanol → Ethyl 5-[(tert-butoxycarbonyl)amino]-1,2-oxazole-3-carboxylate

HRID 1918517

Reaktionsgleichung

Reaktionsgleichung von HRID 1918517
[CH2:1]([O:3][C:4]([C:6]1[CH:10]=[C:9](C(O)=O)[O:8][N:7]=1)=[O:5])[CH3:2].C([N:16]([CH2:19]C)CC)C.[C:21]([OH:25])([CH3:24])([CH3:23])[CH3:22].C1(P(N=[N+]=[N-])(C2C=CC=CC=2)=[O:33])C=CC=CC=1>C1(C)C=CC=CC=1>[C:21]([O:25][C:19]([NH:16][C:9]1[O:8][N:7]=[C:6]([C:4]([O:3][CH2:1][CH3:2])=[O:5])[CH:10]=1)=[O:33])([CH3:24])([CH3:23])[CH3:22]

Komponenten

6

Edukt 4

HCID 6386tert-ButanolHCID 8471TriethylamineHCID 199401P,P-Diphenylphosphinic azideHCID 216484863-Ethyl 3,5-isoxazoledicarboxylate

Produkt 1

HCID 66832013Ethyl 5-[(tert-butoxycarbonyl)amino]-1,2-oxazole-3-carboxylateAusbeute 53,1 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 1140TolueneLösungsmittel

Versuchsvorschrift

To a solution of 3-(ethoxycarbonyl)isoxazole-5-carboxylic acid (2.00 g; 10.80 mmol), triethylamine (1.74 mL; 12.42 mmol) and tert-butanol (2.58 mL; 27.01 mmol) in toluene (25 mL) was added at room temperature diphenylphosphoryl azide (2.74 mL; 12.42 mmol). The solution was stirred at room temperature for 10 min and was heated at 100° C. for 4 h. After evaporation, the residue was purified by flash chromatography on silica gel (eluent: 1 to 6% of ethyl acetate in dichloromethane) to afford 1.47 g (53%) of ethyl 5-(tert-butoxycarbonylamino)isoxazole-3-carboxylate as a white solid.

Aufarbeitung

  1. temperaturewas heated at 100° C. for 4 h
  2. customAfter evaporation
  3. customthe residue was purified by flash chromatography on silica gel (eluent: 1 to 6% of ethyl acetate in dichloromethane)

Quellen und Nachweise

ORD-Eintrag
ord-fe947580c6a545eab9cc296ab03a6425
Quelldatensatz
uspto-grants-2013_12
Patentnummer
US08618138B2

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