Reaktion #47188

Reaktionsgleichung

15

Montmorillonite K10

cinnamaldehyde

DDQ

EtOH

→

Ethyl cinnamate

Ausbeute 94.0%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeis taken in a round bottom flask
2. 2
   TemperaturThe mixture is refluxed for 6 hrs under Dean Stark apparatus
3. 3
   SonstigeAfter completion of the reaction (observed by TLC and by GC analysis)
4. 4
   Filtrationthe reaction mixture is filtered
5. 5
   Waschenwashed with EtOH (10 ml×2)
6. 6
   EinengenConcentrate the filtrate under reduced pressure
7. 7
   Sonstigethe crude product thus obtained
8. 8
   Wascheneluted with diethyl ether

Vorschrift

A homogeneous mixture containing cinnamaldehyde (7.5 mmol), DDQ (11.3 mmol), EtOH (15 mL) and toluene (10 mL) is taken in a round bottom flask and catalytic amount of AMBERLYST® 15 (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 EtOH (10 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. Ethyl cinnamate (from formula I where X1═H, X2═H, X3═H, X4═H, X5═H, R═C2H5) is isolated in 94% yield. 1H-NMR (CDCl3, 300 MHz) δ7.72 (1H, d, J=16.19 Hz), 7.43 (5H, m), 6.47 (1H, d, J=16.19 Hz), 4.28 (2H, q, J=7.09 Hz), 1.34 (3H, t, J=7.09 Hz); 13C-NMR (CDCl3, 75.4 MHz) δ166.9, 144.5, 130.1, 128.8, 128.5, 127.9, 118.2, 60.4, 14.2.

Quelle