General procedure for the synthesis of 3-chloro-2-fluorobenzonitrile from 2,3-dichlorobenzonitrile: Under the protection of nitrogen, 1200g of cyclobutanesulfone, 280g of potassium fluoride, 50g of tetramethylammonium chloride and 688g of 2,3-dichlorobenzonitrile were added to a dry 2L four-necked flask. stirring was turned on, and the temperature was slowly raised to 210°C and kept at this temperature for 8 hours, and the progress of the reaction was monitored by a control sample until the The content of the reaction material was ≤1%. After the reaction was completed, the reaction solution was subjected to short distillation, and 560 g of 2-fluoro-3-chlorobenzonitrile was collected, with the product purity ≥99% and the yield of 90%.
