tert-butyl N-(2-oxocyclopentyl)carbamate → tert-Butyl N-[(2E)-2-{[5-(trifluoromethyl)pyridin-2-yl]methylidene}cyclopentyl]carbamate

Participants

Reaction Steps

To the suspension of diethyl ((5-(trifluoromethyl)pyridin-2-yl)methyl)phosphonate (2.0 g, 6.71 mmol) in THF (50 ml) at 0° C. was added potassium tert-butoxide (1.5 g, 13.42 mmol) and then stirred at room temperature for 30 minutes. To this was then added a solution of tert-butyl N-(2-oxocyclopentyl)carbamate (CAS number 477585-30-1; 1.62 g, 8.05 mmol) in THF (20 ml) and the resulting reaction was stirred at room temperature for 1 hour and then heated at reflux overnight. The reaction was quenched with water (50 ml) and extracted with ethyl acetate (3×100 ml). The combined organics were washed with brine, dried over sodium sulfate and concentrated in vacuo. The resulting residue was purified by column chromatography (silica, 0-15% ethyl acetate/n-hexane) to afford the title compound.

Provenance & Evidence