环戊二烯合成甲基环戊二烯

研究了以环戊二烯、金属钠和一氯甲烷为原料合成甲基环戊二烯的过程,包括制备环戊二烯钠和环戊二烯钠甲基化两步反应。实验结果表明,反应温度及环戊二烯与钠的摩尔比对甲基环戊二烯的收率影响显著。环戊二烯与钠的反应温度初期应控制在0~5℃,以减少环戊二烯二聚反应的发生;后期应升至40℃,以加快反应速率。环戊二烯钠与一氯甲烷甲基化反应的最佳条件为:反应温度25℃、环戊二烯与钠的摩尔比2.25、溶剂二乙二醇二甲醚与钠的摩尔比1.9。在此条件下,甲基环戊二烯的收率高达84.8%,二甲基环戊二烯的收率仅为1.6%。

Synthesis of Methylcyclopentadiene from Cyclopentadiene

Methylcyclopentadiene was synthesized from cyclopentadiene,metallic sodium and methane chloride by a two-step method,which included synthesis of cyclopentadiene sodium by reaction of cyclopentadiene with metallic sodium and successive methylation of cyclopentadiene sodium with methane chloride.The product can raise octane number of gasoline in environmental-friendly manner.Reaction temperature and ratio of cyclopentadiene to sodium in the first step can remarkably influence yield of methylcyclopentadiene.Reaction temperature of this step should be controlled in range of 0-5 ℃ in initial stage of reaction to minimize cyclopentadiene dimerization,and controlled at 40 ℃ in the later stage to accelerate the reaction.For methylation between cyclopentadiene sodium and methyl chloride,the optimal reaction conditions are: temperature 25 ℃,mole ratio of cyclopentadiene to sodium 2.25 and mole ratio of diethylene glycol dimethylether(solvent) to sodium 1.9.Under the conditions,yield of methylcyclopentadiene reaches 84.8% and yield of undesired byproduct dimethylcyclopentadiene is only 1.6%.