Реакция #48042

Уравнение реакции

NH4Cl

Cyclobutanone

1,4-dibromobenzene

n-BuLi

→

1-(4-bromophenyl)-cyclobutanol

Выход 34.3%

Растворители

Water

ether

Условия реакции

Обработка

1. 1
   workup.STIRRINGthe reaction mixture was stirred at −78° C. for 15 min
2. 2
   Температураslowly (over 2 h) warmed to 0° C.
3. 3
   workup.STIRRINGstirred for a further 1 h
4. 4
   Экстракцияthe reaction mixture was extracted with ether
5. 5
   ПромывкаThe organic layer was washed with brine
6. 6
   Сушкаdried (MgSO4)
7. 7
   Фильтрацияfiltered
8. 8
   Концентрированиеconcentrated in vacuo
9. 9
   Другоеto give a residue which
10. 10
    Другоеwas purified by flash column chromatography (1:4 ether/pentane)

Методика

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).

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