反应详情

(1S,2S,4R)-4-carbamoyl-2-methoxycyclopentyl nitrate (example 14, 0.14 g, 0.68 mmol) and bis(2-oxo-3-oxazolidinyl)phosphinic chloride (0.19 g, 0.75 mmol) were stirred for 10 minutes in dichloromethane (5 mL) and triethylamine (0.29 mL, 2.1 mmol). Semicarbazide hydrochloride (0.082 g, 0.73 mmol) was added and stirred at room temperature for 4 days. The solution was concentrated in vacuo and brought up in 1 M sodium hydroxide (3 mL, 3.0 mmol) to reflux for 8 hours. Purification of the crude product by reversed-phase mass-directed high-performance liquid chromatography afforded the title compound as a colorless liquid. 1H NMR (500 MHz, CDCl3) δ 1.93-1.98 (m, 1H), 2.34 (dd, J=4.1, 8.3 Hz, 2H), 2.40-2.47 (m, 1H), 2.40-2.47 (m, 1H), 3.42 (quintet, J=6.2 Hz, 1H), 3.50 (s, 3H), 3.93-3.96 (m, 1H), 5.40-5.43 (m, 1H).

1. concentrationThe solution was concentrated in vacuo
2. temperatureto reflux for 8 hours
3. customPurification of the crude product by reversed-phase mass-directed high-performance liquid chromatography