Synthesis
The general procedure for the synthesis of (3-fluorophenyl)hydrazine from 3-fluoroaniline was as follows: 3-fluoroaniline (0.17 mol) and aqueous NaNO2 (71.0 mL, 1.24 mol) were added sequentially to an aqueous solution of hydrochloric acid (115 mL), and the temperature of the reaction was maintained between 0 and 5 °C. The reaction mixture was stirred continuously for 2 h before the pH was adjusted to 6-7 with 12% w/v sodium carbonate solution. After continuous stirring of the reaction mixture for 2 h, the pH was adjusted to 6-7 with 12% w/v sodium carbonate solution. the resulting diazonium salt solution was added dropwise to sodium sulfite solution (443.0 mL, 1.9 mol) below 0°C. Subsequently, the mixture was stirred at room temperature for 1 h. Concentrated hydrochloric acid (277.0 mL) was slowly added and the reaction system was heated to 100 °C and maintained at this temperature for 3 h. The reaction was carried out at room temperature for 1 h. The mixture was then cooled and the reaction was completed. After completion of the reaction, the mixture was cooled to room temperature and the solid product was collected by filtration and dried to obtain the target compound (3-fluorophenyl)hydrazine.
References
[1] European Journal of Medicinal Chemistry, 2016, vol. 120, p. 37 - 50
[2] Journal of Medicinal Chemistry, 1991, vol. 34, # 9, p. 2892 - 2898
[3] Molecules, 2016, vol. 21, # 11,
[4] Patent: CN106518716, 2017, A. Location in patent: Paragraph 0018-0024
[5] Patent: CN106518722, 2017, A. Location in patent: Paragraph 0037-0042
