General procedure for the synthesis of (S)-2-(2-((tert-butoxycarbonyl)amino)propanoylamino)acetic acid from the compound (CAS: 26061-06-3): compound 9a (2.6 g, 10 mmol) was dissolved in 50 mL of methanol, 1 M NaOH solution (30 mL) was added, and the reaction was stirred for 3 h at room temperature. Upon completion of the reaction, the solvent was removed by concentration under reduced pressure and the residue was adjusted to pH 2-3 with 1 M hydrochloric acid.Subsequently, the mixture was extracted three times with ethyl acetate (EtOAc). The organic phases were combined and dried over anhydrous sodium sulfate (Na2SO4). After filtration, ethyl acetate was removed by evaporation under reduced pressure to give the target product compound 10a as a white solid in 92.4% yield with a melting point of 102-105°C.
