HCID 86664612, compound → HCID 67491791, compound

Participants

Reaction Conditions

Reaction Steps

A solution of tert-butyl 4-((5-bromo-1-tert-butyl-1H-pyrazol-4-yl)methyl)-4-isocyanatopiperidine-1-carboxylate (225 mg, 0.51 mmol) in THF (10 mL) was cooled to −78° C. and t-butyl lithium (0.6 mL, 1.7 M in pentane) was added, dropwise, over 2 minutes. The mixture was stirred 30 minutes at −78° C., warmed to 0° C., and then quenched with saturated aqueous NH4Cl (20 mL). The mixture was stirred 30 minutes at room temperature, diluted with water (25 mL), and then extracted with ethyl acetate (2×50 mL). The combined organics were dried over sodium sulfate, filtered and concentrated. The residue was purified by flash chromatography (12-100% ethyl acetate/heptane, 10 g silica gel) to yield 137 mg of tert-butyl 1′-tert-butyl-7′-oxo-1′,4′,6′,7′-tetrahydrospiro[piperidine-4,5′-pyrazolo[3,4-c]pyridine]-1-carboxylate as a colorless solid. +ESI (M-tBu) 307.2; 1H NMR (400 MHz, DMSO-d6, δ): 7.74 (s, 1H), 7.30 (s, 1H), 3.51 (m, 2H), 3.20 (m, 2H), 2.79 (s, 2H), 1.64 (s, 9H), 1.56 (t, J=5.8 Hz, 4H), 1.38 (s, 9H).

Provenance & Evidence