In a reaction flask, 1,4-dibromobutane (216 g, 1.0 mol) and 40% sodium hydride (90 g, 1.5 mol) were added, and the mixture was slowly heated to 50°C under nitrogen protection. Methyl acetoacetate (116 g, 1.0 mol) was slowly added, maintaining the temperature below 55°C. After the addition was complete, the mixture was heated and stirred at 50°C for 3 hours. The reaction was monitored by TLC until the reactants were fully reacted. Then, 1N... The pH of the reaction solution was adjusted to 8-9 with HCl solution, and the temperature was maintained at 60℃ for 2 hours. Then the temperature was lowered to 40℃. The organic phase was separated, washed once with 100 mL of saturated sodium chloride solution, dried with 5 g of anhydrous magnesium sulfate, and finally concentrated under vacuum to obtain 102 g of 1-CYCLOPENTYL-ETHANONE, with a yield of 91%.
