Alkyl 2-Aryl-2-thioxoethanoates and -thioates: Preparation, Dimerization, and EPR Spectra of the Corresponding Radical Anions
作者:Jürgen Voss、Andrzej Sawluk∗、Gisela Lange、Gunadi Adiwidjaja
DOI:10.1080/10426500902855240
日期:2009.5.14
subsequent treatment of the resulting Bunte salts with sodium hydroxide in a two-phase system. Under elimination of sulfite, the deep-blue colored thiones were generated. These labile compounds could not always be isolated from the solutions in a pure state. Instead, frequently the [2+2]-dimers (dialkyl 2,4-diaryl-1,3-dithietane-2,4-carboxylates) or other follow-up products were obtained. Nevertheless, the
标题化合物通过相应的α-卤代羧酸酯或α-卤代硫代羧酸酯与硫代硫酸四乙基铵反应并随后在两相系统中用氢氧化钠处理所得的Bunte盐来制备。在消除亚硫酸盐的情况下,产生深蓝色的硫酮。这些不稳定的化合物不能总是以纯净的状态从溶液中分离出来。相反,经常获得[2+2]-二聚体(二烷基2,4-二芳基-1,3-二硫杂环丁烷-2,4-羧酸酯)或其他后续产物。尽管如此,即使二聚体溶液被内部电解还原,单体自由基阴离子的 EPR 谱也可以被记录下来。在几种情况下观察到额外的 EPR 光谱,我们将其分配给二烷基 2,3-二芳基-2-丁烯-1 的自由基阴离子,4-dioate 自由基阴离子源自相应的 1,3-dithietanes 的电子诱导硫挤出。当 1,4-苯-双-α-硫代酯或-硫代-硫醇酯在更负的电极电位下被电还原时,观察到自由基三阴离子。