Water → 7-Bromo-2,3-dihydro-1-benzofuran

HRID 729839

Reaktionsgleichung

Reaktionsgleichung von HRID 729839
[Li]CCCC.Br[C:7]1[CH:12]=[CH:11][CH:10]=[C:9]([Br:13])[C:8]=1[O:14][CH2:15][CH2:16]Br.O.C(OCC)(=O)C>C1COCC1.CCCCCC>[Br:13][C:9]1[C:8]2[O:14][CH2:15][CH2:16][C:7]=2[CH:12]=[CH:11][CH:10]=1

Komponenten

7

Edukt 4

HCID 962WaterHCID 8857Ethyl AcetateHCID 292722841,3-Dibromo-2-(2-bromoethoxy)benzeneHCID 178418339Butyllithium

Produkt 1

HCID 225718697-Bromo-2,3-dihydro-1-benzofuranAusbeute 78,5 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 8028TetrahydrofuranLösungsmittelHCID 8058HexaneLösungsmittel

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

A solution of 2.5M n-BuLi (13.0 ml, 32.5 mmol) was added to a solution of 1,3-dibromo-2-(2-bromo-ethoxy)-benzene (11.5, 32.0 mmol) in 115 ml of THF and 28 ml of hexane at −78° C. over 30 mins. The reaction was continued at −78° C. for 30 minutes, then warmed to 0° C. The mixture was poured into water (100 ml) and the aqueous phase was extracted with ether. The combined organic layers were dried over Na2SO4, filtered, and concentrated to give a pale yellow oil. Silica gel chromatography using a gradient of ethyl acetate in hexanes to give 7-bromo-2,3-dihydro-benzofuran as colorless needles (5.00 g, 78%). 1H NMR (500 MHz, DMSO-d6) δ 7.27 (dd, 1 Hz, 8 Hz, 1H), 7.20 (dd, 1 Hz, 7.5 Hz, 1H), 6.75 (t, 7.8 Hz, 1H), 4.59 (t, 9 Hz, 2H), 3.28 (t, 8.8 Hz, 2H).

Aufarbeitung

  1. extractionthe aqueous phase was extracted with ether
  2. dry with materialThe combined organic layers were dried over Na2SO4
  3. filtrationfiltered
  4. concentrationconcentrated
  5. customto give a pale yellow oil

Quellen und Nachweise

ORD-Eintrag
ord-b811a4301cee4900be5e64bcea41bb57
Quelldatensatz
uspto-grants-2009_09
Patentnummer
US07582637B2

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