1121527-35-2

76572-84-4

24424-99-5

1121527-35-2

At 0 °C, 4-(ethylamino)butyric acid (1.15 g, 8.77 mmol) was dissolved in a solvent mixture of 1,4-dioxane (50 mL) and water (50.0 mL) containing potassium carbonate (0.997 mL, 17.53 mmol). Di-tert-butyl dicarbonate (2.218 mL, 9.64 mmol) was slowly added, followed by stirring the reaction mixture at 23 °C overnight. Upon completion of the reaction, most of the solvent was removed by concentration under reduced pressure. The remaining aqueous phase was washed with ether to remove unreacted feedstock and by-products. The aqueous layer was acidified with 5% KHSO4 solution to pH ≈ 3 and then extracted twice with ethyl acetate (EtOAc). The organic phases were combined, dried with anhydrous magnesium sulfate (MgSO4), filtered and concentrated under reduced pressure to afford the target product N-Boc-N-ethyl-4-aminobutyric acid (1.55 g, 76% yield). The product was characterized by 1H NMR (400 MHz, CDCl3): δ 1.11 (t, J = 7.03 Hz, 3H), 1.46 (s, 9H), 1.85 (dt, J = 14.06, 7.03 Hz, 2H), 2.37 (t, J = 7.03 Hz, 2H), 3.16-3.32 (m, 4H); the mass spectrometry (ESI) showed ( M + H)+ m/z = 232.27.