Potassium Carbonate → Tert-butyl 4-(4-bromo-3-cyanopyrazol-1-yl)piperidine-1-carboxylate

Participants

Reaction Steps

4-bromo-2H-pyrazole-3-carbonitrile (500 mg), potassium carbonate (522 mg) and tert-butyl 4-methylsulfonyloxypiperidine-1-carboxylate (975 mg) in acetonitrile (15 ml) were stirred at 90° C. overnight. The mixture was concentrated and the residue was dissolved in ethylacetate, washed with water and brine, dried over magnesium sulfate and concentrated. The crude product was purified by flash chromatography on silica gel eluting with 10 to 50% ethyl acetate in petroleum ether. The solvent was evaporated to dryness to afford. tert-butyl 4-(4-bromo-3-cyano-pyrazol-1-yl)piperidine-1-carboxylate (627 mg) The product gave the following characterizing data: NMR Spectrum: (DMSOd6) 1.41 (s, 9H), 1.74 (dd, 1H), 1.78 (dd, 1H), 1.98-2.08 (m, 2H), 2.90 (bs, 2H), 3.95-4.11 (m, 2H), 4.46-4.57 (m, 1H), 8.45 (s, 1H).

Provenance & Evidence