Réaction #6294

Équation de réaction

sodium chloride

4-(N-2-acetoxyethyl-N-ethylamino)benzaldehyde

1,3-dioxolan-2-ylmethyltributylphosphonium bromide

Potassium t-butoxide

→

cinnamaldehyde

4-(N-2-hydroxyethyl-N-ethylamino)cinnamaldehyde

Solvants

dimethylformamide

dimethylformamide

HCl

water

Conditions de réaction

Traitement

1. 1
   Températureheating
2. 2
   TempératureAfter cooling to room temperature
3. 3
   SéchageThe combined organics are dried over 4A sieves
4. 4
   Filtrationfiltered through cotton
5. 5
   Autreevaporated
6. 6
   AutreThe crude reaction product
7. 7
   ExtractionAfter neutralization with saturated sodium bicarbonate, the aqueous mixture is extracted with three portions of ether
8. 8
   Séchagethe combined organics are dried over 4A sieves
9. 9
   Filtrationfiltered through cotton
10. 10
    Autreevaporated

Mode opératoire

To a solution of 235.3 g (1 mole) of 4-(N-2-acetoxyethyl-N-ethylamino)benzaldehyde in dimethylformamide is added 738.7 g (2.0 moles) of 1,3-dioxolan-2-ylmethyltributylphosphonium bromide in dimethylformamide, and the mixture is heated at 90° C. Potassium t-butoxide (224.4 g, 2.0 moles) is added, and heating is continued at 90° C. for 16 hours. After cooling to room temperature, the solution is poured into a seven-fold excess of water, the aqueous mixture is saturated with sodium chloride, The combined organics are dried over 4A sieves, filtered through cotton, and evaporated. The crude reaction product is dissolved in 3M HCl, and the reaction is stirred at room temperature for 16 hours. After neutralization with saturated sodium bicarbonate, the aqueous mixture is extracted with three portions of ether, and the combined organics are dried over 4A sieves, filtered through cotton, and evaporated to yield the cinnamaldehyde as an oil. The product is purified by flash chromatography (silica gel, 1:1 hexane:ethyl acetate).

Source