(R)-2-amino-1-(2,2-dimethyl-4H-benzo[d][1,3]dioxin-6-yl)ethan-1-ol (29.8g, 134.0mmol, 1.0eq.) and tetrahydrofuran (300mL) were added to the reaction flask under nitrogen protection, the reaction solution was heated to 40-60°C, and N, N'- Carbonyldiimidazole (22.7 g, 140.0 mmol, 1.05 eq.).After the addition, the reaction solution was kept at a temperature of 40-60° C. and stirred until the raw material reaction was completed. After the reaction, the solution was cooled to 15-30° C., and water (400 mL) was added. Then, the mixture was continuously cooled to 0-10°C and kept stirring. The precipitated solid was filtered, and the filter cake was washed with water. The filter cake was collected and dried under reduced pressure to obtain 2-Oxazolidinone, 5-(2,2-diMethyl-4H-1,3-benzodioxin-6-yl)-, (5R)- (30 g, 120.4 mmol, 89.9% yield).
