反应详情

To a solution of 4-(4-fluorophenyl)oxazolidine-2,5-dione (2.5 g, 12.8 mmol) in THF (30 mL) cooled to −25° C. was added benzyl chloroformate (2.3 mL, 16.6 mmol), followed by the slow addition (˜10 min) of N-methylmorpholine (2.11 mL, 19.2 mmol) as a solution in THF (5 mL). The solution was stirred at this temperature for 1 h. and then allowed to warm to rt overnight. The resulting solution was filtered through Celite, and the filtrate was concentrated. The resulting crude material was recrystallized from 2:2:1 t-butyl methyl ether:hexanes:THF to give benzyl 4-(4-fluorophenyl)-2,5-dioxooxazolidine-3-carboxylate (2.7 g, 64%) which was used without further purification.

1. filtrationThe resulting solution was filtered through Celite
2. concentrationthe filtrate was concentrated
3. customThe resulting crude material was recrystallized from 2:2:1 t-butyl methyl ether