Water → 4-{2-[5-(4-Acetylpiperazin-1-yl)pyridin-2-yl]ethyl}benzyl tert-butyl hydrazine-1,2-dicarboxylate

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Reaction Steps

To a suspension of (4-{2-[5-(4-acetylpiperazin-1-yl)pyridin-2-yl]ethyl}phenyl)methanol (115.3 mg, 0.340 mmol) in anhydrous N,N-dimethylformamide (1.5 ml) was added 1,1′-carbonyldiimidazole (83.1 mg, 0.513 mmol), and the mixture was stirred at room temperature for 1.5 hrs. tert-Butyl carbazate (137.5 mg, 1.040 mmol) was added, and the mixture was stirred at room temperature 7 hrs. tert-Butyl carbazate (134.8 mg, 1.020 mmol) was added, and the mixture was stirred at room temperature for 16 hrs. tert-Butyl carbazate (135.7 mg, 1.027 mmol) was further added, and the mixture was stirred at 50° C. for 8 hrs. Water was added, and the mixture was extracted twice with ethyl acetate. The combined organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was suspended in dichloromethane (15 ml), collected by filtration, washed with dichloromethane and dried under reduced pressure. The residue was purified by silica gel column chromatography (methanol:dichloromethane=1:20). The fraction containing the target product was concentrated and the obtained solid was suspended in a mixture of ethyl acetate (1 ml) and diisopropyl ether (4 ml), collected by filtration and dried under reduced pressure to give 4-{2-[5-(4-acetylpiperazin-1-yl)pyridin-2-yl]ethyl}benzyl tert-butyl hydrazine-1,2-dicarboxylate (148.6 mg, yield 87.9%) as a white solid.

Provenance & Evidence