Benzoyl chloride → Benzoic acid, 2-benzoylhydrazide

After 10 g (73 mmol) of benzohydrazine was put into a 300 mL three-neck flask, 25 mL of N-methyl-2-pyrrolidone was added thereto, and the mixture was stirred, a mixed solution of 10 mL of N-methyl-2-pyrrolidone and 10 mL (88 mmol) of benzoyl chloride was dripped into the mixture through a 50 mL dropping funnel. The mixture was stirred at 80° C. for 3 hours, and the contents of the flask were reacted together. After the reaction, the reaction solution was added to approximately 500 mL of water and the mixture was stirred, so that a solid was precipitated out. The precipitated solid was collected by suction filtration. The collected solid was washed with water, methanol was added to the obtained solid, and the mixture was washed, so that 10 g of a powdery white solid, which was the object of the synthesis, was obtained at a yield of 57%.