反应详情

A homogeneous mixture containing cinnamaldehyde (7.5 mmol), SeO2 (11.3 mmol), dodecanol (5 mL) and toluene (10 mL) is taken in a round bottom flask and catalytic amount of neutral 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. Dodecylcinnamate (from formula I where X1═H, X2═H, X3═H, X4═H, X5═H, R═C12H25) is isolated in 87% yield. 1H-NMR (CDCl3, 300 MHz) δ7.51 (1H, d), 7.28 (2H, m), 7.14 (3H, m), 6.26 (1H, d), 4.02 (2H, t), 1.50 (2H, t), 1.11 (18H, m), 0.73 (3H, d); 13C-NMR (CDCl3, 75.4 MHz) δ166.4, 144.2, 134.4, 129.6, 128.6, 127.9, 118.2, 64.3, 31.9, 29.7, 29.6, 29.4, 28.7, 26.0, 22.7, 14.0.

1. customis taken in a round bottom flask
2. additioncatalytic amount of neutral alumina (0.1 g) is added to it
3. temperatureThe mixture is refluxed for 6 hrs under Dean Stark apparatus
4. customAfter completion of the reaction (observed by TLC and by GC analysis)
5. filtrationthe reaction mixture is filtered
6. washwashed with ethylacetate (5 ml×2)
7. concentrationConcentrate the filtrate under reduced pressure
8. customthe crude product thus obtained
9. washeluted with diethyl ether