Sodium hydride → Methyl 5-(benzofuran-2-yl)-2,4-dimethyl-3,5-dioxopentanoate

HRID 1357192

Reaktionsgleichung

Reaktionsgleichung von HRID 1357192
[H-].[Na+].[CH3:3][CH:4]([C:9](=[O:12])[CH2:10][CH3:11])[C:5]([O:7][CH3:8])=[O:6].[Li]CCCC.[O:18]1[C:22]2[CH:23]=[CH:24][CH:25]=[CH:26][C:21]=2[CH:20]=[C:19]1[C:27]([O:29]C)=O.OS([O-])(=O)=O.[K+]>C1COCC1>[O:18]1[C:22]2[CH:23]=[CH:24][CH:25]=[CH:26][C:21]=2[CH:20]=[C:19]1[C:27](=[O:29])[CH:10]([CH3:11])[C:9](=[O:12])[CH:4]([CH3:3])[C:5]([O:7][CH3:8])=[O:6]

Komponenten

7

Edukt 5

HCID 24758Sodium hydrideHCID 291153Methyl 1-benzofuran-2-carboxylateHCID 516920Potassium bisulfateHCID 545860Methyl 2-methyl-3-oxopentanoateHCID 178418339Butyllithium

Produkt 1

HCID 15462823Methyl 5-(benzofuran-2-yl)-2,4-dimethyl-3,5-dioxopentanoate

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel2×

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

After adding 60% NaH (220 mg) to a solution of methyl 2-methyl-3-oxopentanoate (750 mg) in THF (5 ml) at 0° C. and stirring at 0° C. for 5 minutes, the mixture was cooled to −78° C. To this reaction solution there was added 1.63 M n-BuLi (3.3 ml), and the mixture was stirred at −78° C. for 30 minutes to prepare a dienolate. A solution of methyl 2-benzofurancarboxylate (300 mg) in THF (10 ml) was added to the dienolate, and the mixture was stirred at −78° C. for 20 minutes. The reaction solution was allowed to return to 0° C., aqueous KHSO4 was added for quenching, and extraction was performed with AcOEt. The organic layer was rinsed with saturated saline and dried with MgSO4, and then filtered and concentrated. The residue was crudely purified by silica gel column chromatography (n-hexane/AcOEt=3/1→2/1) to obtain methyl 5-(benzofuran-2-yl)-2,4-dimethyl-3,5-dioxopentanoate.

Aufarbeitung

  1. temperaturethe mixture was cooled to −78° C
  2. stirringthe mixture was stirred at −78° C. for 30 minutes
  3. customto prepare a dienolate
  4. stirringthe mixture was stirred at −78° C. for 20 minutes
  5. customto return to 0° C.
  6. customfor quenching
  7. extractionextraction
  8. washThe organic layer was rinsed with saturated saline
  9. dry with materialdried with MgSO4
  10. filtrationfiltered
  11. concentrationconcentrated
  12. customThe residue was crudely purified by silica gel column chromatography (n-hexane/AcOEt=3/1→2/1)

Quellen und Nachweise

ORD-Eintrag
ord-923f2329c92442bbbf8bc2efab1c0960
Quelldatensatz
uspto-grants-2003_07
Patentnummer
US06589984B1

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