In a 3000 L reactor, 201.6 kg of potassium hydroxide (KOH), 253.2 kg of 3,4,5-trifluorobromobenzene and 1500 L of methanol were added sequentially. The reaction kettle was sealed, stirring was turned on and heated to 60°C, and the reaction was maintained for 6 hours until the raw materials were basically reacted completely. The reaction mixture was transferred to a crystallization tank, protected by the passage of nitrogen, cooled to -5 °C with stirring and maintained at this temperature for 5 hours to promote crystallization. Subsequent filtration was performed to afford the target product 2,3-difluoro-5-bromoanisole in 92.0% yield and 99.2% purity. The methanol in the filtrate was recycled and processed for use in subsequent reactions.
