反应详情

温度

55 °C

Compound (3) (392 mg, 2 mmol) was dissolved in isobutyric acid (264 mg, 3 mmol) and the solution was slowly added to a pre-mixed solution of isobutyric acid (264 mg, 3 mmol) and diisopropylethylamine (387 mg, 3 mmol). The reaction mixture was heated to 55° C. for 16 h, then diluted with ether (50 mL), washed with water (2×10 mL), saturated bicarbonate solution (2×10 mL) and brine (10 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to give the title compound (8) as a colorless liquid (450 mg, 90%). The product was further purified by vacuum distillation (170° C./20 Torr). 1H NMR (CDCl3, 400 MHz): δ 1.16 (d, J=7.2 Hz, 6H), 1.47 (s, 9H), 1.48 (d, J=5.6 Hz, 3H), 2.53 (m, 1H), 6.90 (q, J=5.2 Hz, 1H).

1. washwashed with water (2×10 mL), saturated bicarbonate solution (2×10 mL) and brine (10 mL)
2. dry with materialdried over anhydrous sodium sulfate
3. filtrationfiltered
4. concentrationconcentrated in vacuo