General procedure for the synthesis of propyl 3-bromoacetate from ethanoic anhydride and 3-bromo-1-propanol: To a stirred solution of 3-bromo-1-propanol (8.0 g, 57.55 mmol) in anhydrous dichloromethane (40 mL) was added triethylamine (12 mL, 86.32 mmol) and stirred for 1 h at room temperature. Ethanoic anhydride (6.5 mL, 69.06 mmol) dissolved in dichloromethane (5 mL) was added dropwise at 0 °C, followed by stirring for 16 h at room temperature. The reaction process was monitored by thin layer chromatography (TLC). Upon completion of the reaction, the reaction mixture was quenched with 1N hydrochloric acid solution and extracted with dichloromethane. The combined organic layers were washed with brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography with 10% ethyl acetate/hexane as eluent to give the target product propyl 3-bromoacetate. Yield: 10.0 g, 96% yield; 1H NMR (400 MHz, CDCl3) δ 4.19-4.17 (m, 2H), 3.47 (t, J=6.5 Hz, 2H), 2.21-2.18 (m, 2H), 2.06 (s, 3H).