Boron tribromide → 5-[5-(5-Chloro-2-hydroxy-phenyl)-isoxazol-3-yl]-pentanoic acid ethyl ester

HRID 1616600Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1616600
B(Br)(Br)Br.[CH2:5]([O:7][C:8](=[O:27])[CH2:9][CH2:10][CH2:11][CH2:12][C:13]1[CH:17]=[C:16]([C:18]2[CH:23]=[C:22]([Cl:24])[CH:21]=[CH:20][C:19]=2[O:25]C)[O:15][N:14]=1)[CH3:6]>C(Cl)Cl>[CH2:5]([O:7][C:8](=[O:27])[CH2:9][CH2:10][CH2:11][CH2:12][C:13]1[CH:17]=[C:16]([C:18]2[CH:23]=[C:22]([Cl:24])[CH:21]=[CH:20][C:19]=2[OH:25])[O:15][N:14]=1)[CH3:6]

Komponenten

4

Edukt 2

HCID 25134Boron tribromide2×HCID 591677645-[5-(5-Chloro-2-methoxy-phenyl)-isoxazol-3-yl]-pentanoic acid ethyl ester

Produkt 1

HCID 1364006035-[5-(5-Chloro-2-hydroxy-phenyl)-isoxazol-3-yl]-pentanoic acid ethyl esterAusbeute 87,9 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel

Versuchsvorschrift

Add boron tribromide (39 mL, 39 mmol, 1.0 M solution in CH2Cl2) dropwise to a stirred −78° C. solution of 5-[5-(5-chloro-2-methoxy-phenyl)-isoxazol-3-yl]-pentanoic acid ethyl ester (4.39 g, 13 mmol) in CH2Cl2 (40 mL). Allow to warm to room temperature. After 2 hours, cool to −78° C. and add boron tribromide (13 mL, 13 mmol, 1.0 M solution in CH2Cl2) dropwise and allow to warm to room temperature overnight. Quench via dropwise addition of ethanol (60 mL, absolute). Concentrate, dissolve residue in CHCl3, wash with saturated NaHCO3 solution (×2), dry over MgSO4 and concentrate to get 3.7 g of a tan solid. Adsorb on SiO2 and purify the residue by flash chromatography on silica gel eluting with 0-60% EtOAc/hexanes to afford the title compound (3.3 g, 78%). MS (IS) 324 (M+1)+.

Aufarbeitung

  1. temperaturecool to −78° C.
  2. temperatureto warm to room temperature overnight
  3. customQuench via dropwise addition of ethanol (60 mL, absolute)
  4. concentrationConcentrate
  5. dissolutiondissolve residue in CHCl3
  6. washwash with saturated NaHCO3 solution (×2)
  7. dry with materialdry over MgSO4
  8. concentrationconcentrate

Quellen und Nachweise

ORD-Eintrag
ord-2ac302ec7fa04bacbc57e052a9ce1988
Quelldatensatz
uspto-grants-2014_07
Patentnummer
US08765796B2

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