Bromine → 7-Bromo-2-ethyl-4-methoxybenzoxazole

HRID 275803Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 275803
[CH2:1]([C:3]1[O:4][C:5]2[CH:11]=[CH:10][CH:9]=[C:8]([O:12][CH3:13])[C:6]=2[N:7]=1)[CH3:2].[Br:14]Br>CO>[Br:14][C:11]1[C:5]2[O:4][C:3]([CH2:1][CH3:2])=[N:7][C:6]=2[C:8]([O:12][CH3:13])=[CH:9][CH:10]=1

Komponenten

4

Edukt 2

HCID 24408BromineHCID 183166412-Ethyl-4-methoxybenzoxazole2×

Produkt 1

HCID 224566737-Bromo-2-ethyl-4-methoxybenzoxazole

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 887MethanolLösungsmittel

Reaktionsbedingungen

Temperatur
-78 °C

Versuchsvorschrift

2-Ethyl-4-methoxybenzoxazole (2.81 g) was dissolved in methanol (80 ml) under nitrogen and the solution cooled to −78° C. Bromine (0.73 ml) was added dropwise. The mixture was allowed to warm gradually to room temperature and stirred for 3.5 h. The methanol was evaporated in vacuo and the residue partitioned between ethyl acetate and aqueous sodium bicarbonate. The combined organic phases were washed with 5% aqueous sodium metabisulphite, evaporated onto silica and purified by flash chromatography eluting with 25%-50% ethyl acetate in hexane to give a mixture of the title compound and 2-ethyl-4-methoxybenzoxazole as a pale yellow liquid (2.28 g).

Aufarbeitung

  1. temperatureto warm gradually to room temperature
  2. customThe methanol was evaporated in vacuo
  3. customthe residue partitioned between ethyl acetate and aqueous sodium bicarbonate
  4. washThe combined organic phases were washed with 5% aqueous sodium metabisulphite
  5. customevaporated onto silica
  6. custompurified by flash chromatography
  7. washeluting with 25%-50% ethyl acetate in hexane
  8. customto give

Quellen und Nachweise

ORD-Eintrag
ord-3b74867e9f394e5b92aaa56e9c97350d
Quelldatensatz
uspto-grants-2002_03
Patentnummer
US06353010B1

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