Reaktion #40776

Reaktionsgleichung

HCl

KOH

Benzaldehyde

butyraldehyde

→

desired product

Ausbeute 70.0%

2-Benzylidene-butyraldehyde

Ausbeute 70.0%

Lösungsmittel

EtOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooled with an ice bath
2. 2
   workup.ADDITIONAdded
3. 3
   Extraktionextracted with ether
4. 4
   TrocknenThe organic layer was dried over Na2SO4
5. 5
   Filtrationfiltrated
6. 6
   Einengenconcentrated in vacuo
7. 7
   workup.DISTILLATIONVacuum distillation
8. 8
   Sonstigeyielded 20.4 g of a yellow fluid (78-82° C., 0.6 mbar)

Vorschrift

30.0 mL Benzaldehyde was dissolved in 150 mL EtOH and cooled with an ice bath. Added was 5.01 mL 45% KOH (0.2 equiv.), followed by dropwise addition of 16.5 mL butyraldehyde. The mixture was stirred for 3 days at room temperature, acidified with 1M HCl and extracted with ether. The organic layer was dried over Na2SO4, filtrated and concentrated in vacuo. Vacuum distillation yielded 20.4 g of a yellow fluid (78-82° C., 0.6 mbar) containing 70% of the desired product. This material was used in subsequent steps without further purification. Characteristic signals in 1H NMR (400 MHz, CDCl3): δ 1.15 (t, J=7.5 Hz, 3H), 2.57 (q, J=7.5 Hz, 1H), 7.22 (s, 1H), 9.56 (s, 1H).

Quelle