N-benzylglycine hydrochloride (3 g, 14.88 mmol) and di-tert-butyl dicarbonate (3.25 g, 14.88 mmol) were reacted in dichloromethane (40 mL). Triethylamine (6.22 mL, 44.6 mmol) was added to the reaction system and stirred at room temperature for 6 days. Upon completion of the reaction, the reaction mixture was partitioned with dichloromethane and dilute hydrochloric acid and the organic phase was extracted with dichloromethane (3 x 20 mL). The organic layers were combined, washed sequentially with water (20 mL) and brine (20 mL) and dried over anhydrous magnesium sulfate. Concentration gave the target product N-BOC-N-benzylglycine (5 g, 125% yield) as a clear, colorless oil containing a small amount of triethylamine hydrochloride impurity. The product was characterized by 1H NMR (400 MHz, CDCl3): δ1.38-1.46 (d, 9H), 3.71 (s, 1H), 3.86 (s, 1H), 4.54 (d, J=12.38Hz, 2H), 7.07-7.37 (m, 5H). The product does not require further purification and can be used directly in the next reaction.
