Ethyl 4-hydroxy-3-methyl-1-benzofuran-2-carboxylate → 5-Fluoro-4-hydroxy-3-methyl-benzofuran-2-carboxylic acid ethyl ester

HRID 843178Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 843178
[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12]([OH:16])[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2].[F:17][B-](F)(F)F.F[N+]1C(Cl)=CC=CC=1Cl>ClCCl>[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][C:13]([F:17])=[C:12]([OH:16])[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2]

Komponenten

4

Edukt 2

HCID 748649Ethyl 4-hydroxy-3-methyl-1-benzofuran-2-carboxylateHCID 27373072,6-Dichloro-1-fluoropyridiniumtetrafluoroborate

Produkt 1

HCID 540733565-Fluoro-4-hydroxy-3-methyl-benzofuran-2-carboxylic acid ethyl esterAusbeute 27,7 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel

Versuchsvorschrift

To a solution of 4-hydroxy-3-methyl-benzofuran-2-carboxylic acid ethyl ester (Joseph G. Atkinson et al., European patent application 0146243 (1985)) (700 mg) in dichloromethane (20 ml) was added 1-fluoro-2,6-dichloropyridinium tetrafluoroborate (807 mg) at room temperature and the mixture was stirred overnight. The reaction was quenched by the addition of water (10 ml), extracted with ethyl acetate (20 ml), washed with brine and dried over anhydrous magnesium sulfate. The mixture was separated by silica gel column chromatography developed by dichloromethane and methanol. 5-fluoro-4-hydroxy-3-methyl-benzofuran-2-carboxylic acid ethyl ester (210 mg) was obtained as a white solid. EI-MS: m/z 238 (MH+); 1H-NMR (CDCl3): δ 1.50 (3H, t, J=7.3 Hz), 2.82 (3H, s), 4.46 (2H, q, J=7.3 Hz), 6.99 (1H, dd, J=3.3 Hz, 8.9 Hz), 7.15 (1H, dd, J=8.9 Hz, 10.6 Hz). And 7-fluoro-4-methyl-benzofuran-2-carboxylic acid ethyl ester was obtained as a colorless oil. EI-MS: m/z 238 (MH+); 1H-NMR (CDCl3): δ 1.44 (3H, t, J=7.3 Hz), 2.76 (3H, s), 4.46 (2H, q, J=7.3 Hz), 6.47 (1H, dd, J=3.0 Hz, 8.6 Hz), 6.97 (1H, dd, J=8.6 Hz, 10.2 Hz).

Aufarbeitung

  1. customThe reaction was quenched by the addition of water (10 ml)
  2. extractionextracted with ethyl acetate (20 ml)
  3. washwashed with brine
  4. dry with materialdried over anhydrous magnesium sulfate
  5. customThe mixture was separated by silica gel column chromatography

Quellen und Nachweise

ORD-Eintrag
ord-47fb3f8450ff42f89170af0bd1b57867
Quelldatensatz
uspto-grants-2002_04
Patentnummer
US06376491B1

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