Synthesis
Step 3: Synthesis of 1-(piperazin-1-yl)isoquinoline (2c)
1-Chloroisoquinoline (3 g, 18.3 mmol, 1 equiv) was dissolved in acetonitrile (150 mL) with piperazine (23.7 g, 274.5 mmol, 15 equiv) and potassium carbonate (3.8 g, 27.5 mmol, 1.5 equiv). The reaction mixture was heated to reflux for 48 hours. Upon completion of the reaction, the mixture was concentrated, diluted with dichloromethane (250 mL) and washed sequentially with saturated aqueous sodium bicarbonate and brine. The organic phase was separated, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to afford the target product 1-(piperazin-1-yl)isoquinoline 2c (3.9 g, 94% yield).LC-MS (M+H+): 214.1.
References
[1] Patent: WO2016/96631, 2016, A1. Location in patent: Page/Page column 27-28
[2] Patent: WO2016/96686, 2016, A1. Location in patent: Page/Page column 33-34
[3] Chemical and Pharmaceutical Bulletin, 2009, vol. 57, # 1, p. 34 - 42
[4] Journal of Medicinal Chemistry, 2010, vol. 53, # 3, p. 1023 - 1037
