Volatiles were removed by distillation under reduced pressure at room temperature and the crude product 5-(chloromethyl)-2-furancarbonyl chloride (4, 2.90 g) was dissolved in anhydrous ethanol (20 mL). The resulting clarified yellow solution was reacted at 50 °C with continuous stirring for 6 hours. Upon completion of the reaction, the solvent was removed by rotary evaporator and the resulting residue was purified by column chromatography using dichloromethane/hexane (1:1 to 3:1 gradient) as eluent to afford the target product, ethyl 5-(chloromethyl)furan-2-carboxylate (5), as a colorless oil (2.390 g, 82% yield). The structure of the product was confirmed by 1H NMR (300 MHz, CDCl3) and 13C NMR (75 MHz, CDCl3): 1H NMR δ 7.06 (d, J = 3.5 Hz, 1H), 6.44 (d, J = 3.5 Hz, 1H), 4.55 (s, 2H), 4.31 (q, J = 7.1 Hz, 2H), 1.32 (t, J = 7.1 Hz, 3H); 13C NMR δ 158.35, 153.96, 145.02, 118.54, 111.37, 61.10, 36.68, 14.26.
