In this study, we discuss the utility of bis(cyanoacetamides) as versatile precursors to the piperazine‐mediated synthesis of a wide spectrum of bis(thieno[2,3‐b ]pyridine) derivatives, linked to aliphatic spacers via thioethers. The proposed tandem protocol involved the reaction of bis(cyanoacetamides) with two equivalents of the appropriate cinnamonitriles in dioxane in the presence of six equivalents of piperazine at reflux for 4 hours. Then, two equivalents of the appropriate halogen‐containing reagents were added and the reaction was heated at reflux for further 3 hours. The bis(thieno[2,3‐b ]pyridines) were taken as a key intermediates to new bis(4‐oxopyrido[3′,2′:4,5]thieno[3,2‐d ]pyrimidines). The above derivatives were reacted with the appropriate hydrazonyl chloride derivatives in dioxane in the presence of triethylamine to yield the corresponding bis([1,2,4]triazoles) with a related fused pyridothienopyrimidine moiety. The new structures were elucidated by IR, NMR spectral data, as well as elemental analyses.

中文翻译：

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哌嗪介导的双（噻吩并[2,3-b]吡啶）串联合成：相关的稠合[1,2,4]三唑并[4,3-a]嘧啶的多功能前体

在这项研究中，我们讨论了双（氰基乙酰胺）作为通用的前体在哌嗪介导的宽范围的双（噻吩并[2,3- b ]吡啶）衍生物合成中的用途，这些衍生物通过硫醚与脂肪族间隔基连接。拟议的串联方案涉及双（氰基乙酰胺）与两当量的适当肉桂腈在二恶烷中，六当量哌嗪的存在下回流反应4小时。然后，加入两当量的适当的含卤素试剂，并将反应加热回流三小时。bis（thieno [2,3- b ]吡啶）被用作新bis（4-oxopyrido [3'，2'：4,5] thieno [3,2- d ]的关键中间体]嘧啶）。在三乙胺存在下，使上述衍生物与适当的酰氯酰氯在二恶烷中反应，得到具有相关的稠合吡啶并噻吩并嘧啶部分的相应双（[[1,2,4]三唑）。通过IR，NMR光谱数据以及元素分析来阐明新结构。