反应详情

Methanesulfonic anhydride (825 mg, 4.74 mmol) was added to a solution of 1-isoxazol-3-ylethanol (C6 from the previous step, 536 mg) and triethylamine (0.90 mL, 6.5 mmol) in THF (10 mL), and the reaction mixture was stirred for 18 hours. After addition of ethyl acetate, the mixture was washed with water, dried over magnesium sulfate, filtered, and concentrated in vacuo. The reaction was judged to be incomplete by proton NMR spectroscopy, so this material was resubjected to the reaction conditions, using two equivalents of methanesulfonic anhydride, and worked up in the same manner. The crude material was purified by silica gel chromatography (Eluants: 25% ethyl acetate in heptane followed by 50% ethyl acetate in heptane) to provide the product as a colorless oil. Yield: 276 mg, 1.44 mmol, 14% over 2 steps. 1H NMR (400 MHz, CDCl3) δ 1.81 (d, J=6.6 Hz, 3H), 3.01 (s, 3H), 5.93 (q, J=6.6 Hz, 1H), 6.50 (d, J=1.8 Hz, 1H), 8.45 (d, J=1.7 Hz, 1H).

1. washthe mixture was washed with water
2. dry with materialdried over magnesium sulfate
3. filtrationfiltered
4. concentrationconcentrated in vacuo
5. customwas resubjected to the reaction conditions
6. customThe crude material was purified by silica gel chromatography (Eluants: 25% ethyl acetate in heptane followed by 50% ethyl acetate in heptane)