The general procedure for the synthesis of 2-(2-fluoro-4-bromophenyl)-1,3-dioxolane from ethylene glycol and 4-bromo-2-fluorobenzaldehyde was as follows: 4-bromo-2-fluorobenzaldehyde (9.4 g, 46.3 mmol), ethylene glycol (13.2 mL), triethyl orthoformate (6.6 mL), and p-toluene sulfonate (0.09 g, 0.473 mmol) were reacted in aqueous solution in 1,2- Dichloroethane (50 mL) in a stirred reaction at 80 °C for 2.5 hours. After completion of the reaction, it was cooled to room temperature, and the reaction mixture was washed sequentially with saturated sodium bicarbonate solution, water and brine, dried with anhydrous magnesium sulfate, and subsequently concentrated under reduced pressure to afford 11.4 g of the target product (light yellow oil, 100% yield). The 1H NMR (CDCl3) data of the product were as follows: δ 7.41 (t, J = 8.1 Hz, 1H), 7.30 (dd, J = 8.1, 1.8 Hz, 1H), 7.25 (dd, J = 9.6, 1.8 Hz, 1H), 6.02 (s, 1H), 4.13 (m, 2H), 4.04 (m, 2H).
