A series of arylidene thiosemicarbazides have been prepared by a new method, which was titled as transalkylidation. This method is an effective, fast, green and clean method. The mechanism of this reaction has been discussed. Moreover, we clarified the divergences of the structural assignments reported in the literature for the reaction of thiosemicarbazide and aldehydes or ketones in the presence of different catalysts. Where 1,2,4-triazolidine-3-thiones were incorrectly reported as sole product of such reaction, based on occurance of intramolecular cycloaddition of thiosemicarbazones formed in situ. Our findings proved that the reaction stops at earlier stage of thiosemicarbazone and neither cyclization to 1,2,4-triazolidine-3-thiones nor 2-amino-1,3,4-thiadiazoline take place. We have removed the confusion of the NMR interpretation of thiosemicarbazone and their cycloaddition product by carrying out ¹H-NMR, ¹³C-NMR, ¹⁵N-NMR and ¹H-¹⁵N HSQC experiments with temperature gradient. Furthermore, DFT-NMR calculations have been done to make structural distinguish between the three possible structural isomers for this reaction, namely, 1,2,4-triazolidene-3-thione, 2-amino-1,3,4-thiadiazoline and thiosemicarbazone.

已经通过一种新方法制备了一系列的亚芳基硫代氨基脲，其标题为烷基转移。该方法是一种有效，快速，绿色和清洁的方法。已经讨论了该反应的机理。此外，我们澄清了文献中报道的在不同催化剂存在下硫代氨基脲与醛或酮反应的结构分配的差异。其中1,2,4-三唑烷-3-硫酮被错误地报告为此类反应的唯一产物，这是基于分子内原位形成的硫代半氨基甲酮类化合物的环内加成反应。我们的发现证明，该反应在硫半脲的较早阶段停止，并且没有环化成1,2,4-三唑烷-3-硫酮或2-氨基-1,3,4-噻二唑啉。具有温度梯度的¹ H-NMR，¹³ C-NMR，¹⁵ N-NMR和¹ H - ¹⁵ N HSQC实验。此外，已经进行了DFT-NMR计算，以区分该反应的三种可能的结构异构体，即1,2,4-三唑亚甲基-3-硫酮，2-氨基-1,3,4-噻二唑啉和硫代半脲。