Reaktion #2348121

Reaktionsgleichung

(4-Methoxybenzyl)triphenylphosphonium chloride

Sodium methoxide

Pyridinecarbaldehyde

→

trans-stilbene

Ausbeute 61.8%

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITthe stirring was continued at room temperature overnight
2. 2
   SonstigeExcess of sodium methoxide was quenched by addition of water and pH of the reaction mixture
3. 3
   workup.ADDITIONto pH=7.5-8.0 by addition of saturated sodium bicarbonate
4. 4
   ExtraktionProducts were then extracted with ethyl acetate (500 mL)
5. 5
   WaschenCombined extracts were washed with water and brine
6. 6
   Einengenconcentrated in vacuo
7. 7
   SonstigeThe crude product was purified by column chromatography

Vorschrift

(4-Methoxybenzyl)triphenylphosphonium chloride (4.79 g, 11.4 mmol) was suspended in 50 mL of dry methanol. Sodium methoxide (4.94 g of 25% solution in methanol, 22.8 mmol) was added in one portion to the above suspension and the resulting mixture was stirred at room temperature under nitrogen for 30 minutes. Pyridinecarbaldehyde (1.57 g, 11.4 mmol) was then added and the stirring was continued at room temperature overnight. Excess of sodium methoxide was quenched by addition of water and pH of the reaction mixture was adjusted to pH=4.5 with 1 N HCl, and then to pH=7.5-8.0 by addition of saturated sodium bicarbonate. Products were then extracted with ethyl acetate (500 mL). Combined extracts were washed with water and brine, and concentrated in vacuo. The crude product was purified by column chromatography using ethyl acetate in hexane (5%-10%) to give 1.27 g (46%) of trans-stilbene.

Quelle