283167-28-2

4-tert-butoxycarbonylaminopiperidine (5.0 g, 25 mmol) was dissolved in dichloromethane (80 mL) at 0 °C and triethylamine (3.8 g, 38 mmol) and acetic anhydride (2.6 g, 25 mmol) were added sequentially. The reaction mixture was stirred continuously at 0 °C for 2 hours. Upon completion of the reaction, the reaction was quenched by the addition of water (30 mL) and the organic phase was separated and washed with saturated sodium bicarbonate solution (30 mL). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure to give tert-butyl (1-methylpiperidin-4-yl)carbamate (5.6 g, 93% yield) as a light yellow solid.LC-MS analysis: retention time 1.88 min; mass-to-charge ratio 265.1 [M+Na]+.

[1] Patent: WO2016/34673, 2016, A1. Location in patent: Page/Page column 91
[2] Patent: WO2016/34675, 2016, A1. Location in patent: Page/Page column 68
[3] Patent: WO2017/153520, 2017, A1. Location in patent: Page/Page column 64
[4] Patent: US2008/227780, 2008, A1. Location in patent: Page/Page column 53-54
[5] Patent: WO2015/198229, 2015, A1. Location in patent: Page/Page column 21