16948-16-6

15761-38-3

74-88-4

16948-16-6

General method: (S)-2-(tert-butoxycarbonylamino)-3-hydroxypropanoic acid (1 eq.) and iodomethane (10 eq.) were dissolved in anhydrous THF under nitrogen protection and cooled to 0 °C. Pure sodium hydride (10 eq.) was added in batches over 2.0 h. The reaction mixture was kept stirred at 0°C. Subsequently, the reaction mixture was continued to be stirred at room temperature for 24 hours. Upon completion of the reaction, the reaction mixture was diluted with ether (20 mL) and quenched with water (30 mL). The organic layer was separated and the aqueous layer was extracted with ether (2 x 15 mL). The combined organic layers were adjusted to pH 3 with aqueous citric acid and then extracted with EtOAc (3 x 20 mL). The combined EtOAc extracts were dried with anhydrous Na2SO4 and concentrated under reduced pressure to give BOC-N-methyl-L-alanine in 90% yield as a colorless oil.