反应详情

To a solution of 2-(2-methoxyethoxyl)ethanethioamide (Example 6B, 3.26 g, 21.85 mmol) in ethanol (60 mL) was added dropwise ethylbromopyruvate (3.7 mL, 29.5 mmol) and the mixture was refluxed for 18 hours. The reaction was then concentrated under vacuum, diluted with ethyl acetate, washed with water (1×), brine (1×), dried over anhydrous magnesium sulfate, filtered and concentrated. The residue was purified by silica gel column chromatography (3.5×10 cm, 30% ethyl acetate/CH2Cl2) to give the title material (4.36 g, 81%) as an oil. LC (Method F): 1.791 min. 1H NMR (CDCl3, 400 MHz) δ ppm: 8.16 (s, 1H), 4.87 (s, 2H), 4.41 (q, J=7.10 Hz, 2H), 3.74-3.77 (m, 2H), 3.57-3.60 (m, 2H), 3.39 (s, 3H), 1.39 (t, J=7.10 Hz, 3H).

1. temperaturethe mixture was refluxed for 18 hours
2. concentrationThe reaction was then concentrated under vacuum
3. additiondiluted with ethyl acetate
4. washwashed with water (1×), brine (1×)
5. dry with materialdried over anhydrous magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated
8. customThe residue was purified by silica gel column chromatography (3.5×10 cm, 30% ethyl acetate/CH2Cl2)