固载聚乙二醇催化合成异黄樟油素

以聚乙二醇和固载聚乙二醇作为相转移催化剂, 在无溶剂条件下, 黄樟油素经催化异构合成异黄樟油素. 通过正交实验, 得到固载PEG-X (polyethylene glycol-X)催化最优工艺条件为: m(88.5%黄樟油)∶m(KOH)∶m(PEG-X)＝1∶0.2∶0.25, 反应温度90 ℃, 反应时间 5 h, 在此工艺条件下, 异黄樟油素得率为99.9%. 固载PEG-X催化剂循环使用10次后其催化活性未见下降. 结果显示, 固载聚乙二醇催化工艺具有操作简便、反应温度低、时间短、产率高以及对环境友好等优点. 用¹H NMR, GC-MS对异构黄樟油素结构进行了表征, 研究了固载聚乙二醇作为相转移催化剂合成异黄樟油素的反应机理.

Synthesis of Isosafrole Catalyzed by Polyethylene Gly-colSupported on Polystyrene

Isosafrole was synthesized from safrole by PEG-X (polyethylene glycol-X) or PEG-X supported on polystyrene as a phase-transfer catalyst in solvent-free conditions. According to orthogonal experiments, the optimum technological conditions were obtained as follows: m(88.5% safrole)∶m(KOH)∶m(PEG-X)＝1∶0.2∶0.25, temperature 90 ℃ and time 5 h. The yield of isosafrole was 99.9% under such conditions. The PEG-X supported on polystyrene can be used repeatedly for ten times without remarkable loss of catalytic activity. The results showed that this method provides several advantages such as a simple work-up procedure, a shorter reaction time, a lower reaction temperature, a higher yield and environmental friendliness. The structures of isosafrole were determined by ¹H NMR and GC-MS spectra. A possible mechanism for this reaction was proposed by PEG-X supported on polystyrene.