24424-99-5

42116-55-2

General procedure for the synthesis of methyl 3-((tert-butoxycarbonyl)amino)propanoate from di-tert-butyl dicarbonate: β-alanine methyl ester hydrochloride (9.90 g, 70.93 mmol) was suspended in 200 mL of acetonitrile and triethylamine (10 mL, 72.14 mmol) was added. The reaction mixture was stirred at room temperature for 0.3 h. Subsequently, di-tert-butyl dicarbonate (15.48 g, 70.93 mmol) and zirconium(IV) chloride (1.65 g, 7.09 mmol) were added sequentially. The reaction mixture was continued to be stirred at room temperature for 2 hours. After completion of the reaction, the solvent was removed by rotary evaporation. The residue was extracted with ethyl acetate and water, the organic phase was separated and dried over anhydrous sodium sulfate. The dried organic phase was concentrated under reduced pressure to give the target product in a yield of 12.50 g with 87% yield.