Benzyl Bromide → 5-Isopropyl-2,4-bis-methoxymethoxy-benzoic acid hydrazide

5-isopropyl-2,4-bis-methoxymethoxy-benzoic acid (IM3-a: 2.84 g, 10 mmol), N,N′-carbonyldiimidazole (1.62 g, 10 mmol) and tetrahydrofuran 100 mL were placed in a 300 mL eggplant shaped flask and stirred at room temperature for 4 hours. The reaction mixture was mixed with benzylbromide (1.19 mL, 10 mL), stirred at room temperature for further 4 hours and then mixed with hydrazine mono hydrate (0.63 mL, 13 mmol) and stirred at room temperature overnight. After completing the reaction, most of the reaction mixture was removed under reduced pressure, and the residue was mixed with ethyl acetate. The organic layer was washed with saturated sodium hydrogen carbonate and saturated sodium chloride solutions, dried over anhydrous sodium sulfate. After filtration and evaporation, the residue was purified by silica gel column chromatography to obtain the title compound (IM4-a: 2.44 g, 82%).