反应详情

温度

100 °C

To a solution of tributyl(vinyl)stannane (1.1 mL, 3.83 mmol) and ethyl 2-chlorooxazole-5-carboxylate (546 mg, 3.11 mmol) in dioxane (37 mL) is added Pd(PPh3)2Cl2 (222 mg, 0.32 mmol) at room temperature. After stirring at 100° C. under nitrogen for 4 hours, the solution is cooled to ambient temperature and then quenched with H2O. The crude is diluted with EtOAc, the organic layer is washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The obtained residue is purified by flash column chromatography (eluent: heptane/EtOAc=90:10 to 80:20) to give ethyl 2-vinyloxazole-5-carboxylate (470 mg). HPLC retention time=0.39 minutes (condition B); MS (m+1)=168.2; 1H NMR (400 MHz, CD3OD) δ ppm 1.38 (t, J=7.1 Hz, 3 H) 4.38 (q, J=7.2 Hz, 2 H) 5.88 (d, J=11.4 Hz, 1 H) 6.39 (d, J=17.7 Hz, 1 H) 6.69 (dd, J=17.6, 11.2 Hz, 1 H) 7.83 (s, 1 H)

1. temperaturethe solution is cooled to ambient temperature
2. customquenched with H2O
3. additionThe crude is diluted with EtOAc
4. washthe organic layer is washed with brine
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe obtained residue is purified by flash column chromatography (eluent: heptane/EtOAc=90:10 to 80:20)