Synthesis
General procedure for the synthesis of 3-chloro-5-(trifluoromethyl)pyridin-2-ylhydrazine from 2,3-dichloro-5-(trifluoromethyl)pyridine: Hydrazine hydrate (3.15 g) was slowly added to a solution of ethanol (50 mL) containing 2,3-dichloro-5-(trifluoromethyl)pyridine (6.8 g) under ice-bath conditions. The reaction mixture was stirred at 50 °C overnight. Upon completion of the reaction, the mixture was cooled to room temperature and the solvent was subsequently removed by evaporation under reduced pressure. The resulting residue was treated with isopropyl ether (IPE) and the precipitated solid was collected by filtration to give the final target product 3-chloro-5-(trifluoromethyl)pyridin-2-ylhydrazine (7.57 g). Mass spectral analysis (APCI+): [M+H]+ m/z 212.0.
References
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[2] Organic and Biomolecular Chemistry, 2004, vol. 2, # 2, p. 246 - 256
[3] Patent: US5321002, 1994, A
[4] Patent: US2015/266872, 2015, A1. Location in patent: Paragraph 0685; 0686
[5] Letters in Drug Design and Discovery, 2016, vol. 13, # 4, p. 324 - 328
