反应详情

To a stirred solution of ethynylmagnesium bromide (0.5 M in THF, 50 mL, 25 mmol) maintained under nitrogen below 0° C. was added a solution of 1-(5-methyl-1,2-oxazol-3-yl)ethan-1-one (2.5 g, 19.98 mmol) in tetrahydrofuran (20 mL) dropwise over 5 min. The resulting solution was warmed to room temperature and then stirred for a further 3 hr. The reaction was quenched by the addition of saturated ammonium chloride solution (100 mL) then extracted with ethyl acetate (2×100 mL). The combined organic layers was washed with brine (200 mL), dried with anhydrous sodium sulphate and concentrated in vacuo. The residue was purified on a silica gel column, elution with ethyl acetate/petroleum ether (0:1-1:4) afforded the title compound (2.3 g, 75%) as a colorless oil: 1H NMR (300 MHz, CDCl3) delta 6.12 (s, 1H), 3.47 (s, 1H), 2.63 (s, 1H), 2.42 (s, 3H), 1.86 (s, 3H).

1. customThe reaction was quenched by the addition of saturated ammonium chloride solution (100 mL)
2. extractionthen extracted with ethyl acetate (2×100 mL)
3. washThe combined organic layers was washed with brine (200 mL)
4. dry with materialdried with anhydrous sodium sulphate
5. concentrationconcentrated in vacuo
6. customThe residue was purified on a silica gel column, elution with ethyl acetate/petroleum ether (0:1-1:4)