Veratrole → Ethyl 2-(2,3-dimethoxyphenyl)-2-oxoacetate

HRID 31346

Reaktionsgleichung

Reaktionsgleichung von HRID 31346
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[O:9][CH3:10].C([Li])CCC.[C:16](OCC)(=[O:22])[C:17]([O:19][CH2:20][CH3:21])=[O:18].[NH4+].[Cl-]>CCOCC.CCCCCC>[CH3:1][O:2][C:3]1[C:4]([O:9][CH3:10])=[CH:5][CH:6]=[CH:7][C:8]=1[C:16](=[O:22])[C:17]([O:19][CH2:20][CH3:21])=[O:18]

Komponenten

7

Edukt 4

HCID 7043VeratroleHCID 7268Diethyl OxalateHCID 25517Ammonium ChlorideHCID 178418339Butyllithium

Produkt 1

HCID 21905960Ethyl 2-(2,3-dimethoxyphenyl)-2-oxoacetate

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 3283Diethyl EtherLösungsmittelHCID 8058HexaneLösungsmittel

Reaktionsbedingungen

Temperatur
-40 °C

Versuchsvorschrift

A mixture of 27.6 g of 1,2-dimethoxybenzene in 160 ml of ether is cooled to −40° C., 250 ml of a 1.6 M solution of n-butyllithium in hexane are added dropwise and the mixture is then left stirring for 24 hours while allowing the temperature to return to RT. The reaction mixture is cooled to −20° C., 136 ml of diethyl oxalate are added rapidly and the mixture is left stirring while allowing the temperature to return to RT. After stirring for 30 minutes at RT, the reaction mixture is poured into saturated NH4Cl solution, the phases are separated after settling has taken place, the aqueous phase is extracted with ether, the combined organic phases are washed twice with water and dried over Na2SO4, and the solvents are evaporated off under vacuum. The excess diethyl oxalate is removed by distillation under vacuum (b.p.=90° C. at 2 400 Pa). The resulting crude product is chromatographed on silica gel, eluting with a heptane/iso ether mixture (90/10; v/v). 25 g of the expected product are obtained and are used without further purification in the following step.

Aufarbeitung

  1. waitthe mixture is then left
  2. customto return to RT
  3. temperatureThe reaction mixture is cooled to −20° C.
  4. waitthe mixture is left
  5. stirringstirring
  6. customto return to RT
  7. stirringAfter stirring for 30 minutes at RT
  8. customthe phases are separated after settling
  9. extractionthe aqueous phase is extracted with ether
  10. washthe combined organic phases are washed twice with water
  11. dry with materialdried over Na2SO4
  12. customthe solvents are evaporated off under vacuum
  13. customThe excess diethyl oxalate is removed by distillation under vacuum (b.p.=90° C. at 2 400 Pa)
  14. customThe resulting crude product is chromatographed on silica gel
  15. washeluting with a heptane/iso ether mixture (90/10; v/v)

Quellen und Nachweise

ORD-Eintrag
ord-87833b48f9224b76829b3ae1464e07ed
Quelldatensatz
uspto-grants-2008_09
Patentnummer
US07425566B2

Verknüpfte Notizen

Wird geladen…