Ethyl 6-methoxybenzofuran-2-carboxylate → 2-Benzofurancarboxaldehyde, 6-methoxy-

HRID 710332Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 710332
[H-].[H-].[H-].[H-].[Li+].[Al+3].C([O:9][C:10]([C:12]1[O:13][C:14]2[CH:20]=[C:19]([O:21][CH3:22])[CH:18]=[CH:17][C:15]=2[CH:16]=1)=O)C>CCOCC.O1CCOCC1.O=[Mn]=O>[CH3:22][O:21][C:19]1[CH:18]=[CH:17][C:15]2[CH:16]=[C:12]([CH:10]=[O:9])[O:13][C:14]=2[CH:20]=1

Komponenten

6

Edukt 2

HCID 11830962Ethyl 6-methoxybenzofuran-2-carboxylateHCID 21226445Aluminium lithium hydride

Produkt 1

HCID 409082-Benzofurancarboxaldehyde, 6-methoxy-Ausbeute 76 %

Reagenzien, Katalysatoren, Lösungsmittel 3

HCID 14801Manganese dioxideKatalysatorHCID 3283Diethyl EtherLösungsmittelHCID 312751,4-DioxaneLösungsmittel

Versuchsvorschrift

To a stirred slurry LiAlH4 (0.114 g, 3 mmol) in anhydrous Et2O (5 ml) was added drop wise the solution of ethyl-6-methoxybenzofuran-2-carboxylate (0.380 g, 1.73 mmol) and stirring was continued for 0.5 h at room temperature. The reaction mixture was quenched with EtOAc:H2O:MeOH mixture (7:3:1), diluted to 20 ml with EtOAc and filtered through Celite. The filtrate was evaporated and the residue was dried in vacuo to give the creamy paste (0.324 g) which was used as such for next step. This (0.310 g) was dissolved in anhydrous dioxane (10 ml) and MnO2 (1 g, excess) was added to it. The suspension was stirred at reflux for 3 h, cooled to room temperature and filtered through Celite pad. The filtrate was evaporated to dryness and the residue was purified by FCC (SiO2, hexane: EtOAc; 70:30), to give the title compound (0.182 g; 76%), as light pink crystalline solid. 1H-NMR (CDCl3) 3.87 (s, 3H); 6.96 (dd, 1H, J=2.22, 8.73 Hz); 7.03 (d, 1H, J=1.83 Hz); 7.48 (5, 1H); 7.59 (d, 1H, J=8.7 Hz); 9.74 (s, 1H).

Aufarbeitung

  1. customThe reaction mixture was quenched with EtOAc
  2. additionH2O:MeOH mixture (7:3:1), diluted to 20 ml with EtOAc
  3. filtrationfiltered through Celite
  4. customThe filtrate was evaporated
  5. customthe residue was dried in vacuo
  6. customto give the creamy paste (0.324 g) which
  7. stirringThe suspension was stirred
  8. temperatureat reflux for 3 h
  9. filtrationfiltered through Celite pad
  10. customThe filtrate was evaporated to dryness
  11. customthe residue was purified by FCC (SiO2, hexane: EtOAc; 70:30)

Quellen und Nachweise

ORD-Eintrag
ord-1bc59e93d8e44b3290fe46c2211877fb
Quelldatensatz
uspto-grants-2015_11
Patentnummer
US09181182B2

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