Synthesis
CN92108607.5 reports a novel preparation method for 3,3-tetramethyleneglutarimide: 1,1-cyclopentanediacetic acid and urea are mixed in a ratio of 1:1.1-1:1.6 (molar ratio) and stirred at 150-200℃ for 0.5-2 hours. After the reaction, crude 8-azaspiro[4,5]decane-7,9-dione compound is obtained. Then, it is recrystallized with 30-60% ethanol and activated carbon to obtain white crystalline 3,3-tetramethyleneglutarimide compound with a yield of 80.1-89.5% and a melting point of 154-156℃.
The urea used is a readily available and inexpensive raw material. Furthermore, because acetic anhydride is not used, there are no special requirements for the reaction equipment. At the same time, the method of this invention simplifies the reaction steps compared to existing technologies. Therefore, this invention has the advantages of low raw material costs, simple equipment, and short reaction time. It is particularly suitable for industrial production.
