Z-Aib-OH

62-57-7

501-53-1

15030-72-5

The general procedure for the synthesis of Cbz-2-aminoisobutyric acid from 2-aminoisobutyric acid and benzyl chloroformate was as follows: to an aqueous solution (1 L) containing 2-aminoisobutyric acid (50 g, 0.49 mmol) and sodium carbonate (Na2CO3, 156 g, 1.47 mol), benzyl chloroformate (CbzCl, 91 g, 1.47 mmol) was slowly added over 15 min at 0 °C. 0.54 mmol) to a dioxane solution (500 mL). The reaction mixture was stirred at room temperature for 18 hours. Upon completion of the reaction, the aqueous layer was separated and retained by extraction with ether (Et2O, 2 x 500 mL). The aqueous layer was acidified with concentrated hydrochloric acid (cHCl) to pH=1 and then extracted with ethyl acetate (EtOAc, 2 × 500 mL). The organic layers were combined, washed with saturated brine, dried over anhydrous sodium sulfate (Na2SO4), and concentrated under reduced pressure to afford a white solid Cbz-2-aminoisobutyric acid (111 g, 97% yield), which could be used for the next reaction without further purification.