BOC-ABU-OH is generally synthesized from DL-2-aminobutyric acid. The specific synthesis steps are as follows: 10.3 g of DL-2-aminobutyric acid is dissolved in a mixture of 95 mL of 1 M NaOH solution and 65 mL of methanol. 27.5 mL of di-tert-butyl dicarbonate (i.e., Boc anhydride, 1.2 eq.) is added in an ice bath, and the mixture is slowly heated to room temperature with stirring for 12 hours. After the reaction is complete, methanol is removed by rotary evaporation, the pH is adjusted to 1-2 with 1 M hydrochloric acid, and the mixture is extracted with ethyl acetate (50 mL x 3), washed with saturated brine (40 mL x 2), and dehydrated with anhydrous sodium sulfate. Finally, rotary evaporation yields 18.9 g of colorless solid (93.4%).
