1,2-Dibromoethane → 7-Bromo-2-ethyl-4-methoxypyrazolo[1,5-a]pyridine

HRID 9189Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 9189
C([Li])CCC.[CH2:6]([C:8]1[CH:18]=[C:11]2[C:12]([O:16][CH3:17])=[CH:13][CH:14]=[CH:15][N:10]2[N:9]=1)[CH3:7].[Br:19]CCBr.[Cl-].[NH4+]>O1CCCC1>[Br:19][C:15]1[N:10]2[N:9]=[C:8]([CH2:6][CH3:7])[CH:18]=[C:11]2[C:12]([O:16][CH3:17])=[CH:13][CH:14]=1

Komponenten

6

Edukt 4

HCID 78391,2-DibromoethaneHCID 25517Ammonium ChlorideHCID 219845782-Ethyl-4-methoxypyrazolo[1,5-a]pyridineHCID 178418339Butyllithium

Produkt 1

HCID 219845677-Bromo-2-ethyl-4-methoxypyrazolo[1,5-a]pyridine

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Reaktionsbedingungen

Temperatur
-78 °C

Versuchsvorschrift

n-Butyllithium (1.31 mL) was slowly added dropwise to a solution of 2-ethyl-4-methoxypyrazolo[1,5-a]pyridine (303 mg) in tetrahydrofuran (15 mL) at −78° C. After stirring the mixture at −78° C. for 1 hour, 1,2-dibromoethane (0.18 mL) was added and stirring was continued for 1 hour. Saturated aqueous ammonium chloride was added, extraction was performed with ethyl acetate, the extract was washed with brine and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography (20 g), and the title compound (282 mg) was obtained from the n-hexane:ethyl acetate (5:1) fraction as a colorless oil.

Aufarbeitung

  1. stirringstirring
  2. waitwas continued for 1 hour
  3. extractionextraction
  4. washthe extract was washed with brine
  5. dry with materialdried over magnesium sulfate
  6. distillationthe solvent was distilled off under reduced pressure

Quellen und Nachweise

ORD-Eintrag
ord-b182e6e6acd04d0da1ff082f2af748a0
Quelldatensatz
uspto-grants-2006_08
Patentnummer
US07091215B2

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