N-Benzylacetoacetamide

4-Methyleneoxetane-2-one (60.00 g, 713.69 mmol) was dissolved in DCM (600 mL), and the solution was placed at 0 °C. Aniline (91.76 g, 856.43 mmol) was added dropwise to obtain the reaction system. The reaction system was then transferred to room temperature and stirred overnight.

After the reaction was complete, the reaction mixture was concentrated under reduced pressure. The resulting residue was slurried for 1 hour with a mixed solvent of petroleum ether and ethyl acetate (10/1 (v/v), 200 mL), filtered, and the filter cake was washed with a mixed solvent of petroleum ether and ethyl acetate (10/1 (v/v), 100 mL) to give the title compound as a yellow solid (136.38 g, 100%).

N-Benzylacetoacetamide can be used to prepare the compound 1-acetyl-N-benzylcyclopentaneformamide: Acetylacetylbenzylamine (100.00 g, 522.93 mmol) and K2CO3 (216.50 g, 1568.79 mmol) were suspended in DMF (1 L), and 1,4-dibromobutane (169.36 g, 784.4 mmol) was added dropwise to the solution at room temperature to obtain the reaction system. The reaction system was then stirred overnight at room temperature. After the reaction was completed, the reaction mixture was concentrated under reduced pressure, the residue was diluted with water (500 mL), and extracted with ethyl acetate (500 mL x 3). The organic phases were then combined. Next, the combined organic phases were washed with saturated brine (500 mL x 3) and dried over anhydrous sodium sulfate. The mixture was then filtered, the filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (petroleum ether/ethyl acetate (v/v) = 8/1) to give the title compound as a white solid (69.50 g, 54%).

Light Yellow Powder