Synthesis
The general procedure for the synthesis of 4-cyanopiperidine from N-Boc-4-cyanopiperidine is as follows:
Step A: Preparation of 4-cyanopiperidine hydrochloride (mt17-1)
N-Boc-4-cyanopiperidine (4.00 g, 19.0 mmol) was dissolved in 20 mL of 4M HCl/EtOAc solution and stirred at room temperature for 30 min. After completion of the reaction, the mixture was concentrated under vacuum to give 2.10 g of 4-cyanopiperidine hydrochloride (mt17-1) as a white solid in 100% yield.
1H-NMR (DMSO-d6) δ: 9.32 (br, 1H), 3.18-3.08 (m, 3H), 2.97-2.92 (m, 2H), 2.08-2.04 (m, 2H), 1.95-1.85 (m, 2H).
References
[1] Patent: WO2014/178, 2014, A1. Location in patent: Page/Page column 102
[2] Patent: WO2014/4416, 2014, A1. Location in patent: Page/Page column 102
[3] Patent: US2014/5103, 2014, A1. Location in patent: Paragraph 0459; 0460
[4] Patent: US2015/197531, 2015, A1. Location in patent: Paragraph 0460
[5] Chemical and Pharmaceutical Bulletin, 2001, vol. 49, # 7, p. 822 - 829
