A solution of the Fmoc-OX derivatives (20 mmol) in 100 mL acetone was added dropwise to a stirred solution of Alanine (20 mmol) and NaHCO
3 (50 mmol) in 100 mL water. After stirring overnight the reaction mixture was concentrated under reduced pressure and then extracted with CH
2Cl
2 (50 mL) to remove the unreacted Fmoc-OX derivatives. The reaction mixture was cooled and acidified with 10% HCl to congo red litmus paper to give a white solid, which was filtered and washed with water several times, dried to give a white solid (FMOC-Ala-OH).Yield=89.5%.