反应详情

温度

95 °C

Isovalerothioamide (6.0 g, 51 mmol) and ethyl formylchloroacetate (Heterocycles 32 (4), 693–701, (1991), 5.0 g, 33 mmol) are dissolved in dry DMF (20 mL), and heated to 95 degrees C. for 4 hours. The reaction is subsequently cooled to 0 degrees C., and cold water (50 mL) is added. The mixture is basified to pH=8 with solid sodium bicarbonate, then extracted with ether (3×35 mL). The combined organic extracts are washed with water, then saline and dried over magnesium sulfate, filtered, and concentrated. The residue is purified by flash chromatography (ethyl acetate/hexanes 4–10% elution) to give the desired product. NMR (CDCl3, 300 MHz) δ 8.27, 4.45–4.30, 3.70–3.50, 3.00–2.80, 2.30–2.10, 1.40–1.20, and 1.10–0.90.

1. temperatureThe reaction is subsequently cooled to 0 degrees C
2. extractionextracted with ether (3×35 mL)
3. washThe combined organic extracts are washed with water
4. dry with materialsaline and dried over magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. customThe residue is purified by flash chromatography (ethyl acetate/hexanes 4–10% elution)