1029413-55-5

4-Amino-1-(1-Boc-piperidin-4-yl)-1H-pyrazole is used as a reactant in the preparation of pyrazolyl-substituted diaminopyrimidines as dual inhibitors of KDR and Aurora B kinases.

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]+.

[1] Patent: WO2017/44434, 2017, A1. Location in patent: Paragraph 0409
[2] Patent: WO2017/48675, 2017, A1. Location in patent: Paragraph 0456
[3] Patent: CN106478651, 2017, A. Location in patent: Paragraph 1004; 1005; 1006
[4] Patent: CN106478607, 2017, A. Location in patent: Paragraph 0673; 0674; 0675
[5] Patent: WO2015/123722, 2015, A1. Location in patent: Page/Page column 90