The Preparation of Lithium Acetylide-Ethylenediamine
The Preparation of Lithium Acetylide-Ethylenediamine
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DOI：
10.1021/jo01045a069
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发表时间：
1963-10
影响因子：
3.6
通讯作者：
O. F. Beumel;R. F. Harris
中科院分区：
文献类型：
--
作者：
O. F. Beumel;R. F. Harris
高于85时，反应A变得非常快，并发生大量的直接酰胺形成。我们的系统在约80 ℃回流，并产生几乎定量的还原（反应B）。直接酰胺的形成也因游离乙二胺保持在最低限度而最小化。与所引用的工作相反，其中乙二胺是溶剂，因此存在大量过量，乙二胺在其反应时加入，而烃过量。有利于还原而不是直接酰胺形成的两个因素的净结果是基于锂金属的85-95%的产率，与之形成对比的是，使用比苯过量四倍的锂，基于苯的51%环己烯和1.4%环己烷的产率。在我们的工作中没有检测到环己烷。通过在中途点接种反应，总是可以获得结晶材料。
Above 85 reaction A becomes very fast and considerable direct amide formation takes place. Our system refluxes at about 80 and gives nearly quantitative reduction (reaction B). Direct amide formation also is mini-mized by the fact that free ethylenediamine is kept to a minimum. In con-trast to the work cited where ethylenediamine is the solvent and, therefore, is present in large excess, the ethylenediamine was added as it reacted while the hydrocarbon was in excess. The net result of the two factors favoring reduction over direct amide formation is a yield of 85-95% based on lithium metal in contrast to a yield of 51% cyclohexene and 1.4% cyclohexane based on benzene using a fourfold excess of lithium over benzene. No cyclohexane was detected in our work. the crystalline material could always be obtained by seeding the reaction at the half-way point.