16a) Synthesis of ethyl 3-oxo-3-[(phenylmethyl)amino]propanoate: In a dry reaction flask, benzylamine (1.10 g, 10.3 mmol) and ethylmalonyl chloride (1.29 mL, 10.3 mmol) were dissolved in dichloromethane (10 mL), followed by triethylamine (1.44 mL, 10.3 mmol). The reaction mixture was stirred at room temperature for 1 hour. After completion of the reaction, the reaction mixture was diluted with saturated aqueous sodium bicarbonate and extracted with ethyl acetate (3 x 20 mL). The organic phases were combined, dried with anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to give ethyl 3-(phenylmethylamino)-3-oxopropanoate as a yellow oil (2.27 g, 100% yield). The product was confirmed by 1H NMR (400 MHz, chloroform-d): δ 7.55 (broad single peak, 1H), 7.24-7.36 (multiple peaks, 5H), 4.45 (double peak, J = 5.6 Hz, 2H), 4.17 (quartet peak, J = 7.2 Hz, 2H), 3.31 (single peak, 2H), 1.27 (triple peak, J = 7.2 Hz, 3H). The mass spectrum (ES+) showed m/e 222 [M + H]+.
