单质碘催化合成苹果酯

Catalytic Synthesis of 2-Methyl-2-ethyl Acetoacetate-1,3-dioxolane with Iodine

以单质碘为催化剂,通过乙酰乙酸乙酯和乙二醇反应合成了苹果酯,考察了乙酰乙酸乙酯与乙二醇摩尔比、碘催化剂用量、反应时间对产品收率的影响,并用单质碘催化剂与其他催化剂进行催化活性比较。结果表明,在乙酰乙酸乙酯与乙二醇摩尔比1∶1.8,单质碘催化剂用量占反应物总量0.3%,环己烷为带水剂,反应时间1.0h条件下,苹果酯产品收率可达73.2%;单质碘催化剂与其他催化剂相比较,具有反应时间短、催化剂用量少、产品收率高等优点。

2 - Methyl - 2 - ethyl acetoacetate - 1,3 - dioxolane was synthesized from ethyl acetoacetate and ethylene glycol using I2 as catalyst. The effects of molar ratio of ethyl acetoacetate to ethylene, the catalyst dosage and reaction time on the yield of 2 - methyl - 2 - ethyl acetoacetate - 1,3 - dioxolane were investigated. Comparison of catalytic activity of different catalysts was made. Experimental result showed that yield of 2 - methyl - 2 - ethyl acetoacetate - 1,3 - dioxolane could reach 73.2 % under the conditions as follows： molar ratio of ethyl acetoacetate to ethylene 1 ： 1.8, the dosage of catalyst 0.3 % based on feed stocks, cyclohexane as carrying - water reagent, and the reaction time 1.0 hour. The catalyst had a fairly high catalytic activity for the ketalation reaction, and had the characteristics in short reaction time, less catalyst dosage and high yield.