Reaktion #48042

Reaktionsgleichung

NH4Cl

Cyclobutanone

1,4-dibromobenzene

n-BuLi

→

1-(4-bromophenyl)-cyclobutanol

Ausbeute 34.3%

Lösungsmittel

Water

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe reaction mixture was stirred at −78° C. for 15 min
2. 2
   Temperaturslowly (over 2 h) warmed to 0° C.
3. 3
   workup.STIRRINGstirred for a further 1 h
4. 4
   Extraktionthe reaction mixture was extracted with ether
5. 5
   WaschenThe organic layer was washed with brine
6. 6
   Trocknendried (MgSO4)
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated in vacuo
9. 9
   Sonstigeto give a residue which
10. 10
    Sonstigewas purified by flash column chromatography (1:4 ether/pentane)

Vorschrift

To a solution of 1,4-dibromobenzene (1.00 g, 4.24 mmol) at −78° C. in ether (20 ml) was added n-BuLi (2.65 ml, 1.6 M solution in hexane, 4.24 mmol) and the reaction mixture was stirred at −78° C. for 30 min. Cyclobutanone (348 μl, 4.66 mmol) was then added and the reaction mixture was stirred at −78° C. for 15 min. The reaction mixture was then slowly (over 2 h) warmed to 0° C. and stirred for a further 1 h. Water was added followed by sat. NH4Cl and the reaction mixture was extracted with ether. The organic layer was washed with brine, dried (MgSO4), filtered and concentrated in vacuo to give a residue which was purified by flash column chromatography (1:4 ether/pentane) to give 1-(4-bromophenyl)-cyclobutanol (330 mg, 34%) as a colorless oil. 1H NMR (CDCl3, 300 MHz): δ 7.50 (d, J=8.5 Hz, 2H), 7.38 (d, J=8.5 Hz, 2H), 2.57-2.48 (m, 2H), 2.41-2.31 (m, 2H), 2.02 (m, 1H), 1.69 (m, 1H).

Quelle