4-Methylmorpholine → benzyl (4S)-4-ethyl-2,5-dioxo-1,3-oxazolidine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of (4S)-4-ethyl-1,3-oxazolidine-2,5-dione (69.57 g) and benzyl chloroformate (101.1 g) in tetrahydrofuran (800 mL) was cooled to 0° C., N-methylmorpholine (81.74 g) was added dropwise, and the mixture was stirred at 0° C. for 2 hr. A 4 mol/L hydrogen chloride-ethyl acetate solution (86.9 mL) was added dropwise at 0° C. to the reaction mixture, and the precipitated morpholine hydrochloride was filtered off with celite. The filtrate was concentrated under reduced pressure to give the title compound as a pale-yellow oil (yield: 91.58 g, 52%).

Provenance & Evidence