Potassium Carbonate → tert-butyl 6-benzyloxy-2H-1-benzopyran-3-carboxylate

HRID 466171Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 466171
[CH2:1]([O:8][C:9]1[CH:10]=[CH:11][C:12]([OH:17])=[C:13]([CH:16]=1)[CH:14]=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(=O)([O-])[O-].[K+].[K+].[C:24]([O:28][C:29]([CH3:32])([CH3:31])[CH3:30])(=[O:27])[CH:25]=[CH2:26]>CN(C=O)C>[CH2:1]([O:8][C:9]1[CH:10]=[CH:11][C:12]2[O:17][CH2:26][C:25]([C:24]([O:28][C:29]([CH3:32])([CH3:31])[CH3:30])=[O:27])=[CH:14][C:13]=2[CH:16]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Komponenten

5

Edukt 3

HCID 11430Potassium CarbonateHCID 15458tert-Butyl acrylateHCID 8783625-(Benzyloxy)-2-hydroxybenzaldehyde

Produkt 1

HCID 14971253tert-butyl 6-benzyloxy-2H-1-benzopyran-3-carboxylate

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6228DimethylformamideLösungsmittel

Reaktionsbedingungen

Temperatur
100 °C

Versuchsvorschrift

5-Benzyloxy-2-hydroxybenzaldehyde (2.01 g, 8.80 mmol) is dissolved in 30 ml of DMF and treated successively with potassium carbonate (1.22 g, 8.80 mmol) and tert-butyl acrylate (1.22 g, 13.2 mmol). The mixture is heated at 100° C. for 1 hour. The temperature is gradually raised to 135° C. over a period of 2 hours, and held at 135° C. for 1 hour. The resultant dark mixture is cooled and evaporated to remove most of DMF. The residue is partitioned between ether and water, and the aqueous phase is discarded. The organic layer is dried (MgSO4), evaporated and purified by silica gel chromatography (6% ethyl acetate/hexane) to give tert-butyl 6-benzyloxy-2H-1-benzopyran-3-carboxylate as a yellow crystalline solid, m.p. 64°-67° C.

Aufarbeitung

  1. temperatureThe temperature is gradually raised to 135° C. over a period of 2 hours
  2. temperatureThe resultant dark mixture is cooled
  3. customevaporated
  4. customto remove most of DMF
  5. customThe residue is partitioned between ether and water
  6. dry with materialThe organic layer is dried (MgSO4)
  7. customevaporated
  8. custompurified by silica gel chromatography (6% ethyl acetate/hexane)

Quellen und Nachweise

ORD-Eintrag
ord-a50e873b061b4749954183133f982adf
Quelldatensatz
uspto-grants-1992_10
Patentnummer
US05155130

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