19036-43-2

24424-99-5

180181-02-6

Example 6: Synthesis of 3-(tert-butoxycarbonylamino)-2,2-dimethylpropionic acid (19) [00156] Under argon protection, 3-amino-2,2-dimethylpropionic acid (18) (1.2 g, 10.2 mmol), di-tert-butyl dicarbonate (Boc anhydride) (2.3 g, 10.2 mmol) and N,N-diisopropylethylamine (DIPEA) (1.85 mL, 10.23 mmol) were dissolved in N,N-dimethylformamide (DMF) (30 mL) in N,N-dimethylformamide (DMF) and the reaction was stirred at 60°C for 16 hours. After completion of the reaction, the reaction mixture was concentrated under reduced pressure, the residue was dissolved in ethyl acetate (EtOAc), washed with saturated ammonium chloride (NH4Cl) solution, and the organic phase was concentrated again under reduced pressure to afford the title compound 3-(tert-butoxycarbonylamino)-2,2-dimethylpropanoic acid (19) (2.0 g, 91% yield). 1H NMR (300 MHz, CDCl3) δ 1.33 (s, 6H), 1.37 (s, 9H), 2.69 (s, 2H).