反应详情

cis(±)-Benzyl (1-carbamoyl-3-methoxypiperidin-4-yl)carbamate obtained in Example (103b) (0.92 g, 3 mmol), ethyl α-chloroacetoacetate (3.29 g, 20 mmol) and sodium bicarbonate (0.84 g, 10 mmol) were stirred at 120° C. for three hours. The reaction solution was diluted with ethyl acetate, washed with water and brine, and dried over anhydrous magnesium sulfate. Following concentration under reduced pressure, the residue was purified by silica gel column chromatography (elution solvent: ethyl acetate/hexane=1/4, 1/2, 2/1, 4/1) to obtain 0.39 g of the title compound as a light brown solid (27%).

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