101759-74-4

34306-42-8

74-88-4

140224-14-2

Step 1: Iodomethane (2.45 mL, 39.4 mmol) was added to a solution of (S)-2-(tert-butoxycarbonylamino)butyric acid (1.00 g, 4.92 mmol) in tetrahydrofuran (THF, 16.4 mL) at 0 °C, followed by batchwise addition of sodium hydride (60% w/w dispersed in mineral oil, 590 mg, 14.8 mmol). The reaction mixture was gradually warmed to room temperature and stirred for 18 hours. Upon completion of the reaction, the mixture was cooled to 0 °C and the reaction was quenched by careful addition of water. The reaction mixture was washed with ether (Et2O) and the aqueous layer was acidified with 1 M hydrochloric acid and then extracted with ether. The organic layers were combined, washed with saturated aqueous sodium bicarbonate (NaHCO3), then dried over anhydrous sodium sulfate (Na2SO4), filtered and concentrated to give (S)-2-(tert-butoxycarbonyl(methyl)amino)butanoic acid (1.05 g, 98% yield) as a white solid. Mass spectrum (MS) m/z 240 (MNa+).