Cesium carbonate → tert-butyl 4-[4-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl]piperidine-1-carboxylate

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Reaction Conditions

Reaction Steps

A mixture of tert-butyl 4-[(methylsulfonyl)oxy]piperidine-1-carboxylate (7.33 g, 26.2 mmol), 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (5.09 g, 26.2 mmol), and Cs2CO3 (12.8 g, 39.3 mmol) in DMF (50 mL) was heated at 100° C. for 24 h. The mixture was cooled to RT and diluted with water (100 mL) and extracted with EtOAc (3×60 mL). The combined organic phases were washed with water (3×50 mL), brine (50 mL), and dried over anhydrous sodium sulfate. The residue was purified by flash chromatography (20 to 40% ethyl acetate:hexanes) to afford 3.84 g (39%) of the title compound as a white solid. 1H NMR (400 MHz, CDCl3): δ 7.81 (s, 1H), 7.74 (s, 1H), 4.17-4.35 (m, 3H), 2.89 (m, J=11.12 Hz, 2H), 2.14 (d, J=14.65 Hz, 2H), 1.90 (qd, J=12.25, 4.42 Hz, 3H), 1.48 (s, 9H), 1.33 (s, 12H); MS (ESI): 379.15 [M+H]+; HPLC tR=3.17 min.

Provenance & Evidence