Example 1: Preparation of 4-phenylmorpholin-3-one
To a solution of N-phenylethanolamine (6.0 mL, 47.8 mmol) in isopropanol (IPA, 6 mL) heated to 40°C was added chloroacetyl chloride (11.4 mL, 143.4 mmol) and 10 N sodium hydroxide solution (29.6 mL, 296 mmol) dropwise at the same time, keeping the pH of the reaction system between 7 and 8. After dropwise addition, the reaction mixture was continued to be stirred at 40 °C for 10 min, followed by cooling to 0 °C and stirring for 1 h at that temperature. Upon completion of the reaction, the white solid product formed was collected by filtration, washed with cold water and dried to afford 4-phenylmorpholin-3-one (5.27 g, 62% yield) as a white solid. The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3): δ 7.42 (t, J = 8.0 Hz, 2H), 7.34-7.27 (m, 3H), 4.35 (s, 2H), 4.04 (t, J = 5.2 Hz, 2H), 3.77 (t, J = 5.2 Hz, 2H).
