反应详情

A homogeneous mixture containing cinnamaldehyde (7.5 mmol), DDQ (11.3 mmol), ethylene glycol (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 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-Hydroxyethyl cinnamate (from formula I where X1═H, X2═H, X3═H, X4═H, X5═H, R═C2H5O) is isolated in 88% yield. 1H-NMR (CDCl3, 300 MHz) δ7.65 (1H, d, J=16.55 Hz), 7.42 (2H, m), 7.29 (3H, m), 6.38 (1H, d, J=16.55 Hz), 4.37 (2H, t), 3.66 (2H, t); 13C-NMR (CDCl3, 75.4 MHz) δ166.4, 145.6, 134.2, 130.5, 128.9, 128.2, 117.3, 64.1, 41.8.

1. customis taken in a round bottom flask
2. temperatureThe mixture is refluxed for 6 hrs under Dean Stark apparatus
3. customAfter completion of the reaction (observed by TLC and by GC analysis)
4. filtrationthe reaction mixture is filtered
5. washwashed with ethylacetate (5 ml×2)
6. concentrationConcentrate the filtrate under reduced pressure
7. customthe crude product thus obtained
8. washeluted with diethyl ether