Hydrochloric Acid → tert-Butyl cis(+/-)-4-{[(4-chloro-5-ethyl-1H-imidazol-2-yl)carbonyl]amino}-3-methoxypiperidine-1-carboxylate

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Reaction Steps

WSC hydrochloride (580 mg, 3.02 mmol) and DMAP (125 mg, 1.02 mmol) were added to a solution of tert-butyl cis(±)-4-amino-3-methoxypiperidine-1-carboxylate obtained in Example (1e) (230 mg, 0.99 mmol) and ethyl 4-chloro-5-ethyl-1H-imidazole-2-carboxylate obtained in Example (1d) (85 mg, 0.49 mmol) in DMA (5 mL), and the mixture was stirred at room temperature for three hours. Dilute hydrochloric acid was added to the reaction solution, followed by extraction with ethyl acetate. Then, the organic layer was washed with water, saturated aqueous sodium bicarbonate solution and brine, and dried over anhydrous sodium sulfate. Following concentration under reduced pressure, the residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=1/1, ethyl acetate) to obtain 117 mg of the title compound as a pale yellow solid (62%).

Provenance & Evidence