5-bromo-2-fluoropyridin-3-ylboronic acid (0.41 mole), potassium difluorohydride (0.82 mole), by 500rpm high-speed stirring for 10 minutes, to get mixed homogeneous material, through the twin-screw extruder inlet continuous addition, extrusion time is set to 5 minutes, extruded material is directly received in a receiver containing an equal weight of water as the solid material, stirred and dispersed, to get the slurry, filtered, the filtrate Return to the receiver, the filter cake is washed and dried in hot air to obtain the product (5-bromo-2-fluoropyridin-3-yl) potassium trifluoroborate.
