114873-00-6

24424-99-5

19883-78-4

114873-00-6

General steps: 1. 2-Fluoro-L-phenylalanine (1.00 g) was dissolved in a mixture of dioxane (10 ml) and water (5 ml) under cooling conditions in an ice bath. 2. 1N aqueous sodium hydroxide solution (5.46 ml) and di-tert-butyl dicarbonate (1.38 ml) were slowly added to the above solution, keeping the reaction system in an ice bath. 3. The ice bath was removed and the reaction mixture was stirred at room temperature for 1 hour. 4. Upon completion of the reaction, the reaction mixture was concentrated under reduced pressure to remove the organic solvent. 5. The pH of the concentrate was adjusted to 2.5 with dilute hydrochloric acid. 6. 6. The aqueous phase was extracted with ethyl acetate (100 ml x 3) and the organic phases were combined. 7. Wash the organic phase with water and saturated saline in turn. 8. 8. Dry the organic phase with anhydrous sodium sulfate and filter to remove the desiccant. 9. The filtrate was concentrated under pressure to obtain the crude product. 10. The crude product was recrystallized with ethyl acetate-petroleum ether mixed solvent to obtain N-Boc-2-fluoro-L-phenylalanine (1.32 g, 85% yield) as colorless crystals.