反应详情

cis(±)-4-Chloro-N-(3-ethoxypiperidin-4-yl)-5-ethyl-1H-imidazole-2-carboxamide hydrochloride obtained in Example (131a) (200 mg, 0.593 mmol) was suspended in dichloromethane (5 mL). Methyl chloroglyoxylate (0.070 mL, 0.76 mmol), triethylamine (0.250 mL, 1.80 mmol) and DMAP (catalytic amount) were added under ice-cooling, and the mixture was stirred at room temperature for one hour. The reaction solution was diluted with ethyl acetate, washed with water 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=7/3→1/0) to obtain 208.1 mg of the title compound as a colorless oily substance (91%).

1. temperaturecooling
2. washwashed with water and brine
3. dry with materialdried over anhydrous sodium sulfate
4. concentrationconcentration under reduced pressure
5. customthe residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=7/3→1/0)