Reaktion #47192

Reaktionsgleichung

cinnamaldehyde

DDQ

2-methoxyethanol

→

2-Methoxyethyl cinnamate

Ausbeute 93.0%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeis taken in a round bottom flask
2. 2
   workup.ADDITIONcatalytic amount of basic alumina (0.1 g) is added to it
3. 3
   TemperaturThe mixture is refluxed for 6 hrs under Dean Stark apparatus
4. 4
   SonstigeAfter completion of the reaction (observed by TLC and by GC analysis)
5. 5
   Filtrationthe reaction mixture is filtered
6. 6
   Waschenwashed with ethylacetate (5 ml×2)
7. 7
   EinengenConcentrate the filtrate under reduced pressure
8. 8
   Sonstigethe crude product thus obtained
9. 9
   Wascheneluted with diethyl ether

Vorschrift

A homogeneous mixture containing cinnamaldehyde (7.5 mmol), DDQ (11.3 mmol), 2-methoxyethanol (25 mL) and toluene (10 mL) is taken in a round bottom flask and catalytic amount of basic alumina (0.1 g) is added to it. The mixture is refluxed for 6 hrs under Dean Stark apparatus. After completion of the reaction (observed by TLC and by GC analysis), the reaction mixture is filtered and washed with ethylacetate (5 ml×2). Concentrate the filtrate under reduced pressure and the crude product thus obtained is loaded on a neutral alumina column and eluted with diethyl ether. 2-Methoxyethyl cinnamate (from formula I where X1═H, X2═H, X3═H, X4═H, X5═H, R═C3H7O) is isolated in 93% yield. 1H-NMR (CDCl3, 300 MHz) δ7.51 (1H, d, J=16.55 Hz), 7.28 (2H, m), 7.15 (3H, m), 6.28 (1H, d, J=16.55 Hz), 4.16 (2H, t), 3.44 (2H, t), 3.18 (3H, s); 13C-NMR (CDCl3, 75.4 MHz) δ166.6, 144.8, 134.3, 130.2, 128.8, 117.8, 70.4, 63.4, 58.7.

Quelle