59524-02-6

3262-72-4

100-39-0

59524-02-6

GENERAL STEPS: To a stirred solution of N-Boc-L-serine (4.87 mmol) in DMF (100 mL) was added cesium carbonate (5.11 mmol) and stirring was continued for 30 minutes. Benzyl bromide (5.84 mmol) was then added and the reaction mixture was stirred for 12 hours. After completion of the reaction, the reaction mixture was diluted with ethyl acetate (25 mL) and washed sequentially with aqueous lithium bromide (3 × 15 mL), aqueous sodium bicarbonate (2 × 15 mL) and saturated saline (2 × 15 mL). The organic layer was dried with anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. The crude product was purified by fast chromatography (eluent: petroleum ether/ether = 1:1) to afford Boc-L-serine benzyl ester (100% yield) as a white solid. rf = 0.26 (petroleum ether/ether = 1:1). To a stirred solution of N-Boc-L-serine (2.44 mmol) in DMF (50 mL) was added cesium carbonate (2.56 mmol) and stirring was continued for 30 min. Benzyl bromide (2.92 mmol) was then added and the reaction mixture was stirred for 12 hours. After completion of the reaction, the reaction mixture was diluted with ethyl acetate (15 mL) and washed sequentially with aqueous lithium bromide (3 × 10 mL), aqueous sodium bicarbonate (2 × 10 mL) and saturated saline (2 × 10 mL). The organic layer was dried with anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. The crude product was purified by fast chromatography (eluent: petroleum ether/ether = 1:1) to give Boc-L-serine benzyl ester (100% yield) as a white solid. rf = 0.26 (petroleum ether/ether = 1:1).