Synthesis
GENERAL METHODS: 2-Fluorophenylidene hydrazine was synthesized routinely by one-pot method (30-58% yield). Ethyl o-fluorobenzoate (10 mmol) was dissolved in ethanol (20 mL). 3N sulfuric acid (2 mL) was added to the solution, followed by refluxing the reaction mixture for 6 hours. The reaction process was monitored by thin layer chromatography (TLC). Upon completion of the reaction, the reaction mixture was neutralized with solid NaHCO3 and excess NaHCO3 was removed by filtration.To the neutralized reaction mixture, hydrazine monohydrate (1.5 mL, 3 mmol) was added and refluxing was continued for 3-6 h to ensure complete reaction. The ethanol and unreacted hydrazine monohydrate were concentrated to 1/3 of the original volume by distillation.The reaction mixture was cooled to room temperature, the resulting solid was filtered and recrystallized from methanol to give crystals of the target product, 2-fluorophenylidenehydrazine (see Supporting Information for specific data).
References
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