Synthesis
To a stirred solution of N-BOC-piperazine (6.0 g, 33.0 mmol, 1.0 eq.) in acetonitrile (60 mL), the reaction mixture was cooled to 0°C. Subsequently, triethylamine (22 mL, 161 mmol, 5.0 eq.) and benzyl bromide (6.0 mL, 35.0 mmol, 1.1 eq.) were added slowly and dropwise. The reaction mixture was stirred continuously for about 6 hours at room temperature. After completion of the reaction, the mixture was diluted with water and extracted with dichloromethane (CH2Cl2). The organic phases were combined, dried over anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure to afford the target product 1-benzyl-4-Boc-piperazine (6.5 g, 76.0% yield) as a white solid.
References
[1] Synthetic Communications, 2009, vol. 39, # 13, p. 2297 - 2303
[2] Patent: WO2017/17630, 2017, A1. Location in patent: Page/Page column 34-35
[3] Journal of Medicinal Chemistry, 2010, vol. 53, # 4, p. 1830 - 1842
[4] Patent: WO2017/58716, 2017, A1. Location in patent: Paragraph 00268
[5] Journal of Heterocyclic Chemistry, 2010, vol. 47, # 1, p. 54 - 62
