Реакция #415972

Уравнение реакции

bromoacetaldehyde diethylacetal

sodium hydride

p-fluorophenol

hexane

→

desired product

Выход 82.0%

4-fluorophenoxyacetaldehyde diethylacetal

Выход 82.0%

Растворители

dimethylformamide

dimethylformamide

Условия реакции

Обработка

1. 1
   Температураfinally heated on a steam bath for 4 hours
2. 2
   Другоеto come to room temperature
3. 3
   Фильтрацияthe precipitated sodium bromide is filtered off
4. 4
   ДругоеDimethylformamide is then removed on a rotary evaporator
5. 5
   workup.ADDITIONthe oil residue is diluted with acetone (100 ml.)
6. 6
   Другоеanother quantity of sodium bromide is precipitated which
7. 7
   Другоеagain is removed by filtration
8. 8
   КонцентрированиеThe filtrate is then concentrated on a rotary evaporator
9. 9
   Другоеleaving an oil residue which
10. 10
    workup.DISTILLATIONdistilled at 87° C./0.05 mm

Методика

A solution of p-fluorophenol (28.1 g., 0.25 mole) in dimethylformamide (30 ml.) is added dropwise to a suspension of hexane (2 × 30 ml.)-prewashed sodium hydride (50% oil dispersion, 12.5 g., 0.26 mole) in dimethylformamide (120 ml.). The resulting mixture is stirred at room temperature for 10 minutes, treated with bromoacetaldehyde diethylacetal (49.3 g., 0.25 mole), and finally heated on a steam bath for 4 hours. The reaction mixture is allowed to come to room temperature and the precipitated sodium bromide is filtered off. Dimethylformamide is then removed on a rotary evaporator, the oil residue is diluted with acetone (100 ml.) and another quantity of sodium bromide is precipitated which again is removed by filtration. The filtrate is then concentrated on a rotary evaporator leaving an oil residue which is vacuum distilled at 87° C./0.05 mm. to yield the desired product as colorless oil (46.7 g., 0.205 mole, 82%). ir (neat) 3.4~3.5, 6.21, 6.64, 8.00, 8.25, 8.83, 9.32, 12.08, 13.20μ; pmr (CCl4)δ1.17 (6H, t, J=7.5Hz), 3.57 (2H, q, J=7.5Hz), 3.61 (2H, q, J=7.5Hz), 3.85 (2H, d, J=5Hz), 4.68 (1H, t, J=5Hz), 6.6-7.1 (4H, m).

Источник