Acetic Acid → (R)-ethyl 1-(2-(1-(4-chloro-1H-pyrazol-1-yl)cyclopropyl)-3H-imidazo[4,5-b]pyridin-5-yl)piperidine-3-carboxylate

Participants

Reaction Steps

Acetic acid (0.5 mL, 8.88 mmol), ethyl 1-(4-chloro-1H-pyrazol-1-yl)cyclopropanecarbimidate (445 mg, 1.78 mmol), a catalytic amount of sulfur, and triethylamine (0.8 mL, 5.92 mmol) were added to a suspension of (R)-ethyl 1-(5,6-diaminopyridin-2-yl)piperidine-3-carboxylate dihydrochloride (500 mg, 1.48 mmol) in ethanol (25 mL) at room temperature. The reaction mixture was heated at reflux for 18 h, then was concentrated under reduced pressure. The resulting residue was partitioned between ethyl acetate and water. The organic layer was dried over sodium sulfate, filtered and concentrated under reduced pressure. The crude material was purified via column chromatography (100-200 mesh silica gel, 25-70% ethyl acetate in petroleum ether) to afford (R)-ethyl 1-(2-(1-(4-chloro-1H-pyrazol-1-yl)cyclopropyl)-3H-imidazo[4,5-b]pyridin-5-yl)piperidine-3-carboxylate (300 mg). MS (ES+) (M+H) 415.2.

Provenance & Evidence