反应详情

To a solution of 1-methylcyclopropanecarboxylic acid (C49) (30 g, 300 mmol) in dichloromethane (500 mL) was added 1,1′-carbonyldiimidazole (51 g, 315 mmol) portion-wise, not allowing the temperature to exceed 25° C. The mixture was stirred at room temperature for 2 hours. N,O-Dimethylhydroxylamine hydrochloride (34.8 g, 357 mmol) was added in one portion and stirred at room temperature for 12 hours. The mixture was washed with water (2×200 mL) and saturated aqueous sodium chloride solution (100 mL), dried over sodium sulfate and concentrated to give crude product as a colorless oil, which was directly used in the next step. Yield: 49 g, 342 mmol, 114%. 1H NMR (400 MHz, CDCl3) δ 3.69 (s, 3H), 3.20 (s, 3H), 1.34 (s, 3H), 1.01 (dd, J=6.4, 4.4 Hz, 2H), 0.53 (dd, J=6.4, 4.4 Hz, 2H).

1. customto exceed 25° C
2. stirringstirred at room temperature for 12 hours
3. washThe mixture was washed with water (2×200 mL) and saturated aqueous sodium chloride solution (100 mL)
4. dry with materialdried over sodium sulfate
5. concentrationconcentrated
6. customto give crude product as a colorless oil, which