To a mixed solution of CH2Cl2 and 5 mL of methanol containing 2-fluoro-4-vinylbenzonitrile (1.3 g, 8.8 mmol), which was cooled to 40°C at -78°C, ozone (at a concentration of 29 g/m3) was drummed at a flow rate of 50 L/h for 30 minutes. Subsequently, argon was passed to remove unreacted ozone. After addition of sodium borohydride (0.67 g, 0.018 mol), the cooling bath was removed and the reaction mixture was stirred at room temperature for 1 hour. After completion of the reaction, the solvent was removed by evaporation and 2M HCl solution was added. The mixture was extracted twice with ether and the combined organic phases were dried with anhydrous Na2SO4 followed by evaporation of the solvent. The crude product was purified by crystallization to afford the target product 2-fluoro-4-(hydroxymethyl)benzonitrile 1.1 g in 81% yield. The structure of the product was confirmed by 1H NMR (300 MHz, CDCl3): δ 7.59 (m, 1H), 7.3-7.2 (m, 2H), 4.79 (d, 2H), 2.26 (t, 1H).
