Synthesis
Potassium carbonate (269 g, 1.95 mol) and pyrrolidine (200 mL, 2.40 mol) were sequentially added to a tetrahydrofuran solution (500 mL) of 3-bromo-1-propanol (200 g, 1.44 mol) at 0 °C. The reaction mixture was stirred and reacted at room temperature for 15 h. After the reaction, ethyl acetate (500 mL) was added to dilute the mixture and stirring was continued for 1 h. The reaction mixture was then stirred at room temperature for 1 h. The reaction mixture was filtered through a diatomaceous earth pad and the diatomaceous earth pad was washed well with ethyl acetate. The filtrate and washings were combined and concentrated under reduced pressure to remove the solvent. To the concentrated residue was added ethyl acetate (500 mL), stirred for 1 hour and then filtered through diatomaceous earth again. The filtrate was concentrated under reduced pressure and purified by reduced pressure distillation (boiling point: 62 °C, 1 mmHg) to give 3-(1-pyrrolidinyl)-1-propanol (156 g, 95% yield). The product was characterized by 1H NMR (400 MHz, CDCl3): δ 1.69-1.78 (6H, m), 2.53-2.59 (4H, m), 2.73 (2H, t, J = 5.6 Hz), 3.81 (2H, t, J = 5.4 Hz), 5.58 (1H, brs).
References
[1] Journal of Medicinal Chemistry, 2008, vol. 51, # 15, p. 4780 - 4789
[2] Patent: EP1852423, 2007, A1. Location in patent: Page/Page column 6; 14
[3] Patent: WO2009/121812, 2009, A1. Location in patent: Page/Page column 72-73
[4] Journal of Medicinal Chemistry, 2017, vol. 60, # 8, p. 3275 - 3288
[5] Patent: WO2018/118852, 2018, A1. Location in patent: Paragraph 0072
