反应详情

温度

100 °C

Selenium dioxide (1.44 g, 13.0 mmol) was added to a solution of acetic acid 1-methyl-1-(2-methyl-pyridin-3-yl)-ethyl ester (1.25 g, 6.48 mmol) dissolved in a mixture of water (2.5 mL) and 1,4-dioxane (25 mL). The resulting mixture was stirred at 100° C. for 60 hours. The solvent was removed under reduced pressure and the brown oil was quenched with saturated NaHCO3 (30 mL) and extracted with CH2Cl2 (5×50 mL). The combined organic extracts were dried (Na2SO4), filtered, and concentrated in vacuo to afford a brown oil. Purification via column chromatography on silica gel (hexanes:EtOAc, 1:1, v/v) afforded acetic acid 1-(2-formyl-pyridin-3-yl)-1-methyl-ethyl ester as a yellow oil (0.62 g, 46%). 1H NMR (CDCl3) δ 1.91 (s, 6H), 2.03 (s, 3H), 7.48 (dd, 1H, J=9.0, 6.0 Hz), 7.83 (dd, 1H, J=9.0, 3.0 Hz), 8.69 (dd, 1H, J=6.0, 3.0 Hz), 10.49 (s, 1H).

1. customThe solvent was removed under reduced pressure
2. customthe brown oil was quenched with saturated NaHCO3 (30 mL)
3. extractionextracted with CH2Cl2 (5×50 mL)
4. dry with materialThe combined organic extracts were dried (Na2SO4)
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customto afford a brown oil
8. customPurification via column chromatography on silica gel (hexanes