Condensations of 1,4-Cyclohexanediones and Secondary Aromatic Amines. The Formation of Alkyldiarylamines and Triarylamines
作者:Kazuo Haga、Masayuki Oohashi、Ryohei Kaneko
DOI:10.1246/bcsj.57.1586
日期:1984.6
Condensation of 1,4-cyclohexanedione with N-alkylarylamines gives N-alkyl-N-arylanilines, and that with diarylamines gives triarylamines. A mechanism involving dehydration of monoenamines of the 1,4-dione is proposed for the reaction. Relative rates of substituted N-ethylanilines on competitive reactions plotted vs. Hammet’s σ values gave −2.0 as the ρ value. In separate reactions, however, a different
1,4-环己二酮与N-烷基芳基胺缩合得到N-烷基-N-芳基苯胺,与二芳基胺缩合得到三芳基胺。该反应提出了一种涉及 1,4-二酮单烯胺脱水的机制。相对于 Hammet σ 值绘制的竞争反应中取代 N-乙基苯胺的相对比率给出 -2.0 作为 ρ 值。然而,在单独的反应中,产率有不同的趋势,即与对氯和对硝基衍生物反应的容易程度。这种差异是根据用作实际催化剂的胺的共轭酸的酸度来解释的。