4-AMino-1-(1-Boc-4-piperidyl)pyrazole

1201916-87-1

1029413-55-5

Step 3) tert-butyl 4-(4-nitro-1H-pyrazol-1-yl)piperidine-1-carboxylate (1.35 g, 4.56 mmol) was dissolved in ethanol (30 mL), and Pd/C catalyst (135 mg, 1.269 mmol, mass % = 10%) was added. The reaction mixture was stirred for 2 hours at room temperature under hydrogen atmosphere. After completion of the reaction, the catalyst was removed by filtration and the filtrate was concentrated under vacuum. The residue was purified by silica gel column chromatography with dichloromethane/methanol as eluent (v/v=50/1 to 25/1) to afford the title product tert-butyl 4-(4-amino-1H-pyrazol-1-yl)piperidine-1-carboxylate as a brown oil (955 mg, 78.7% yield). lc-MS (ESI, cationic) m/z: 211.1 [M-55]+.