Triethylamine → 1-(4-Bromo-2-fluorophenyl)cyclopropanecarbohydrazide

Participants

Reaction Steps

A solution of the compound (26.55 g, 102.5 mmol) obtained in Example 14-3), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (21.6 g, 112.7 mmol), 1-hydroxybenzotriazole monohydrate (17.26 g, 112.7 mmol), triethylamine (42.9 mL, 307 mmol), and tert-butoxycarbonylhydrazide (16.3 g, 123 mmol) in N,N-dimethylformamide (400 mL) was stirred overnight at room temperature. Water was added to the reaction mixture, the mixture was extracted with ethyl acetate, and the organic layer was washed with saturated aqueous sodium hydrogencarbonate and saturated sodium chloride solution and then dried with anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. A 4 M solution (60 mL) of hydrochloric acid in 1,4-dioxane and methanol (300 mL) were added to the obtained partially purified product, and the mixture was stirred at room temperature for 6.5 h. The reaction mixture was concentrated under reduced pressure, dichloromethane was added to the residue, and the organic layer was washed with saturated aqueous sodium hydrogencarbonate and saturated sodium chloride solution and then dried with anhydrous sodium sulfate. The filtrate was concentrated under reduced pressure, hexane was added to the obtained partially purified product, and the solid was collected by filtration to obtain the title compound (11.6 g, 42%) as a colorless solid.

Provenance & Evidence