Potassium Carbonate → Methyl 5-methyl-1-benzofuran-2-carboxylate

HRID 736510Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 736510
[CH3:1][C:2]1[CH:9]=[C:6]([CH:7]=O)[C:5]([OH:10])=[CH:4][CH:3]=1.C([O-])([O-])=O.[K+].[K+].[CH3:17][O:18][C:19](=[O:26])[CH:20](Br)C(OC)=O>[N+](CCCC)(CCCC)(CCCC)CCCC.[Br-].C1(C)C=CC=CC=1>[CH3:17][O:18][C:19]([C:20]1[O:10][C:5]2[CH:4]=[CH:3][C:2]([CH3:1])=[CH:9][C:6]=2[CH:7]=1)=[O:26]

Komponenten

6

Edukt 3

HCID 11430Potassium CarbonateHCID 69184Benzaldehyde, 2-hydroxy-5-methyl-HCID 70087Dimethyl bromomalonate

Produkt 1

HCID 13157012Methyl 5-methyl-1-benzofuran-2-carboxylateAusbeute 42,1 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 74236Tetrabutylammonium BromideKatalysatorHCID 1140TolueneLösungsmittel

Reaktionsbedingungen

Temperatur
25 °C

Versuchsvorschrift

A stirring suspension of 5-methylsalicylaldehyde (1.0 mg, 7.5 mmol), K2CO3(1.55 g, 11.0 mmol), and Bu4NBr (322 mg, 1 mmol) in toluene (30 ml) was treated with dimethylbromomalo-nate (1.06 ml, 8.0 mmol). The suspension was heated to reflux with a Dean-Stark trap for 20 h. The brown suspension was cooled to 25° C. and concentrated in vacuo. The residue was taken in DCM and filtered. The filtrate was washed with H2O, 1N NaOH and brine. The organic layer was dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by column chromatography (10% ethyl acetate/hexane) to afford the title compound 583 (600 mg, 42% yield). LRMS: 190.2 (Calc.); 191.1 (found).

Aufarbeitung

  1. temperatureThe suspension was heated
  2. temperatureto reflux with a Dean-Stark trap for 20 h
  3. concentrationconcentrated in vacuo
  4. filtrationfiltered
  5. washThe filtrate was washed with H2O, 1N NaOH and brine
  6. dry with materialThe organic layer was dried over magnesium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customThe crude residue was purified by column chromatography (10% ethyl acetate/hexane)

Quellen und Nachweise

ORD-Eintrag
ord-64da93472a524eae823b29d3cce048c1
Quelldatensatz
uspto-grants-2009_09
Patentnummer
US07595343B2

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