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

Participants

Reaction Conditions

Reaction Steps

A 1 L, 1-neck flask was charged with 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (20.0 g, 103 mmol), and DMF (250 mL). The reaction mixture was cooled to 0° C. and NaH (2.73 g, 108 mmol) (95%) was added. The reaction mixture was stirred at 0° C. for 1 hour. tert-Butyl 4-(methylsulfonyloxy)piperidine-1-carboxylate (30.2 g, 108 mmol; prepared as in WO 06/021881) was added and the reaction mixture was heated at 100° C. overnight. The reaction mixture was cooled to ambient temperature and diluted with water. The reaction mixture was extracted with EtOAc, and the organic layer washed with brine, dried over sodium sulfate, filtered and concentrated. The crude material was purified on a Biotage 40S column eluting with EtOAc/Hexane 10% to 25% EtOAc. The product was isolated as a white solid (11.3 g, 29%).

Provenance & Evidence