反应详情

(S)-4-methyl-2,5-oxazolidinedione (L-alanine-NCA) (345 mg, 3 mmol) was dissolved in ethyl acetate (20 mL), followed by the addition of acetyl chloride (306 mg, 3.9 mmol) under ice cooling. Further, a solution of 4-dimethyl-aminopyridine (476 mg, 3.9 mmol) in ethyl acetate (15 mL) was added dropwise under ice cooling over 20 minutes. After the resulting mixture was stirred as was at 0° C. for 2 hours, a precipitated salt was filtered off, and the filtrate was concentrated under reduced pressure. The concentration residue was re-dissolved in ethyl acetate (5 mL), and insoluble matter was filtered off. The filtrate was concentrated under reduced pressure to afford the title compound (118 mg, 25%) as a colorless clear syrup.

1. filtrationa precipitated salt was filtered off
2. concentrationthe filtrate was concentrated under reduced pressure
3. dissolutionThe concentration residue was re-dissolved in ethyl acetate (5 mL)
4. filtrationinsoluble matter was filtered off
5. concentrationThe filtrate was concentrated under reduced pressure