In this study, ethyl 3-aminothieno[2,3-b]pyridine-2-carboxylate was taken as a versatile precursor for the one-pot three-component synthesis of related fused pyrimidine hybrids. The tandem protocol involved the reaction of 3-aminothieno[2,3-b]pyridine, dimethylformamide-dimethylacetal, and amines. The reaction afforded a new series of the target pyrimidine hybrids, linked to different arene units, in good to excellent yields. The prior reaction was evaluated in different solvents under traditional heating or microwave irradiation. Moreover, the influence of reaction temperature was also examined. The optimal conditions were obtained under microwave irradiation in dioxane at 110°C for 40 to 60 min. Additionally, by repeating the previous tandem reaction using the appropriate amines at reaction times of 20 to 60 min, a new series of pyrimidine hybrids linked to alkyl, arylthiazole, and benzo[d]thiazole units has been prepared in good to excellent yields. Furthermore, the utility of bis(amines) was examined to conduct the synthesis of new bis(pyrimidine) hybrids linked to aliphatic cores, in excellent yields, using the same protocol at 30 min reaction time.

中文翻译：

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3-Aminothieno[2,3-b]pyridine-2-carboxylate：微波辅助三组分合成新型吡啶并[3',2':4,5]thieno[3,2-d]pyrimidin-4的有效前体(3H)-一杂种

在这项研究中，3-氨基噻吩并[2,3- b ]吡啶-2-羧酸乙酯被用作一锅三组分合成相关稠合嘧啶杂化物的通用前体。串联方案涉及 3-氨基噻吩并[2,3- b]吡啶、二甲基甲酰胺-二甲基缩醛和胺。该反应提供了一系列新的目标嘧啶杂化物，它们与不同的芳烃单元相连，收率很好。在传统加热或微波辐射下，在不同溶剂中评估先前的反应。此外，还研究了反应温度的影响。最佳条件是在二恶烷中在 110°C 下微波辐射 40 到 60 分钟。此外，通过使用适当的胺在 20 到 60 分钟的反应时间重复之前的串联反应，一系列新的嘧啶杂化物与烷基、芳基噻唑和苯并[ d] 噻唑单元已经以良好到极好的收率制备。此外，检查了双（胺）的效用，以在 30 分钟的反应时间内使用相同的方案以优异的产率合成与脂肪族核心相连的新双（嘧啶）杂化物。