Synthesis
General procedure for the synthesis of 3-chloro-6-hydrazinopyridazine from 3,6-dichloropyridazine: 3,6-dichloropyridazine (3 g, 20.14 mmol) was reacted with hydrazine monohydrate (1 g, 20.14 mmol) in a sealed tube at 80 °C for 5 hours. After completion of the reaction, the solvent was removed by evaporation and the resulting crude product was used directly in the next step of the reaction without further purification (Yield: 3.56 g, Yield: 100%). The product [MH]+ was analyzed by liquid chromatography-mass spectrometry (LCMS, Method B) with m/z of 145.1 and retention time (tR) of 0.57 min.
References
[1] Patent: WO2011/18454, 2011, A1. Location in patent: Page/Page column 62-63
[2] Patent: WO2011/20861, 2011, A1. Location in patent: Page/Page column 67
[3] MedChemComm, 2014, vol. 5, # 4, p. 540 - 546
[4] Bulletin of the Korean Chemical Society, 2018, vol. 39, # 7, p. 853 - 857
[5] Patent: KR2018/94194, 2018, A. Location in patent: Paragraph 0221; 0222; 0223; 0224
