Trifluoroacetic acid → Benzyl-2-[2-(tert-butoxycarbonyl)-acetamido]acetate

Participants

Reaction Conditions

Reaction Steps

Benzyl-2-aminoacetate, TFA salt (13; 1.72 g, 5.12 mmol) and carbamoylmethyl-carbamic acid tert-butyl ester (8a; 1.13 g, 6.19 mmol) were dissolved in 40 mL dichloromethane with stirring at 0° C., followed by addition of N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDC; 1.33 g, 7.0 mmol) and triethylamine (1.0 mL, 7.2 mmol), and the reaction was replaced under room temperature with continuous stirring for 6 h. After the reaction was completed, dichloromethane was removed by concentration under reduced pressure. The obtained solid was dissolved in ethyl acetate (50 mL), and then the organic phase was washed by H2O, 5% citric acid, H2O, saturated NaHCO3 and saturated NaCl solution separately, and dried over MgSO4 and concentrated under reduced pressure to remove ethyl acetate to obtain colorless oil-like 14 (1.15 g; 72.6%). 1H-NMR (200 MHz) (CDCl3) δ: 7.28-7.33 (m, 5H, ArH), 6.89 (br, s, 1H, CONHCH2), 5.36 (br, s, 1H, NHBOC), 5.13 (s, 2H, CO2CH2Ph), 4.04 (d, 2H, CH2CO2CH2Ph), 3.81 (d, 2H, CH2NHBOC), 1.40 [s, 9H, CO2C(CH3)3].

Provenance & Evidence