Diethyl Oxalate → Ethyl 2-(3,5-dichloro-2,6-dimethoxypyridin-4-yl)-2-oxoacetate

HRID 1375408Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1375408
[Cl:1][C:2]1[C:3]([O:11][CH3:12])=[N:4][C:5]([O:9][CH3:10])=[C:6]([Cl:8])[CH:7]=1.[Li+].CC([N-]C(C)C)C.[C:21](OCC)(=[O:27])[C:22]([O:24][CH2:25][CH3:26])=[O:23].[Cl-].[NH4+]>C1COCC1>[Cl:8][C:6]1[C:5]([O:9][CH3:10])=[N:4][C:3]([O:11][CH3:12])=[C:2]([Cl:1])[C:7]=1[C:21](=[O:27])[C:22]([O:24][CH2:25][CH3:26])=[O:23]

Komponenten

6

Edukt 4

HCID 7268Diethyl OxalateHCID 25517Ammonium ChlorideHCID 2724682Lithium diisopropylamideHCID 694735033,5-Dichloro-2,6-dimethoxypyridine

Produkt 1

HCID 58786806Ethyl 2-(3,5-dichloro-2,6-dimethoxypyridin-4-yl)-2-oxoacetateAusbeute 78 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel2×

Reaktionsbedingungen

Temperatur
-78 °C

Versuchsvorschrift

A solution of 5.20 g (25 mmol) of 3,5-dichloro-2,6-dimethoxypyridine (J. Bratt, H. Suschitzky, J.C.S. Perkin I, 1983:1689–1693) in 40 mL THF is added dropwise over 30 minutes to a solution of 20 mL (30 mmol) of 1.5 M LDA in 20 mL THF at −78° C. The resulting solution is stirred at −78° C. for 1 hour, and 4.5 mL (33 mmol) of diethyl oxalate is then added. The temperature is allowed to rise slowly to room temperature and aqueous ammonium chloride solution is added, and the solvent is removed under vacuum. The residue is extracted into EtOAc and chromatographed on SiO2, eluting with hexane-EtOAc (9:1), to give 5.97 g (78%) of the title compound: mp (hexane) 195–196° C.

Aufarbeitung

  1. customto rise slowly to room temperature
  2. customthe solvent is removed under vacuum
  3. extractionThe residue is extracted into EtOAc
  4. customchromatographed on SiO2
  5. washeluting with hexane-EtOAc (9:1)

Quellen und Nachweise

ORD-Eintrag
ord-1c76a0564a4b4b7a929680bd5d8bde0a
Quelldatensatz
uspto-grants-2007_01
Patentnummer
US07169778B2

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