Reaktion #310950

Reaktionsgleichung

m-carbomethoxybenzaldehyde

m-carbomethoxybenzyl triphenyl phosphonium bromide

potassium carbonate

→

white needles

Ausbeute 82.3%

3,3'-Dicarbomethoxystilbene

Ausbeute 82.3%

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   SonstigeThe alkaline layer was separated
3. 3
   Extraktionextracted with dichloromethane
4. 4
   Waschenthe combined organic solvent was washed with plenty of water
5. 5
   Sonstigedried
6. 6
   SonstigeEvaporation of the solvent and recrystallization of the residue from ether

Vorschrift

To a mixture of 49.2 g (0.3 mole) of m-carbomethoxybenzaldehyde, 221 g (0.45 mole) of m-carbomethoxybenzyl triphenyl phosphonium bromide and 1.0 g of tetrabutyl ammonium iodide in 500 ml of dichloromethane, 500 ml of 50% solution of potassium carbonate was added. The mixture was stirred at room temperature for 3 hr. The alkaline layer was separated, extracted with dichloromethane and the combined organic solvent was washed with plenty of water and dried. Evaporation of the solvent and recrystallization of the residue from ether gave 73.2 g of white needles of predominantly transisomer. Yield 82%. m.p. softens at 64° C. and melts at 105°-107° C. The infrared spectrum showed absorption at 1720 cm-1 (COOCH3), 1675 cm-1 (trans c=c), 965 cm-1 (trans c=c) and 670 cm-1 (weak cis c=c). NMR (CDCl3) showed 3.9-4.0 (d. COOCH3, 6) 67-72 (d, CH=CH, 2) and 7.3-8.4 (m, aromatic, 8). Anal. calcd. for C18H16O4 : C, 72.97%, H, 5.40. Found: C, 73.02%, H, 5.41%.

Quelle