General procedure for the synthesis of 2,4-difluorobenzamide from 2,4-difluorobenzoyl chloride: in a 250 mL three-necked flask, 150 mL of ammonia was added and cooled down to -10°C. The concentrate of 2,4-difluorobenzoyl chloride was added slowly dropwise, and the reaction was kept incubated for 0.5 h at -10°C, and then brought up to room temperature and continued for 1 h. The reaction was completed by filtration. After completion of the reaction, the product was separated by filtration and the filter cake was dried under vacuum to give 23.8 g of 2,4-difluorobenzamide in 95.5% yield.
