Ethyl 2,4-diamino-5-{[(2E)-2-(1-phenylethylidene)hydrazino]-carbonyl}thiophene-3-carboxylate (3) was synthesized via Gewald reaction that can be readily used as precursor to potentially interesting thiophenes. Compound 3 reacted with cyanoacetamide and/or malononitrile producing thienopyrimidines 4 and 5, respectively. Reaction of compound 3 with hydrazinecarbodithioic acid afforded pyrimidothienotriazepine 6. Treatment of compound 3 with ethylenediamine and carbon disulfide gave (imidazolinyl)thiophene 7. The latter compound can be used as building blocks for the synthesis of various heterocycles. Structures of the newly synthesized compounds were deduced based on their analytical and spectral data.

中文翻译：

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由乙基2,4-二氨基-5-{[（2）合成新型噻吩并嘧啶和噻二氮杂

通过Gewald反应合成了2,4-二氨基-5-{[（（2 E ）-2-（1-苯基亚乙基）肼基]-羰基}噻吩-3-羧酸乙酯（3 ），可以很容易地用作潜在的前体有趣的噻吩。化合物3与氰基乙酰胺和/或丙二腈反应，分别产生噻吩并嘧啶4和5 。化合物3与肼基二硫代硫酸反应，得到嘧啶并二氮杂ze平6 。用乙二胺和二硫化碳处理化合物3 ，得到（咪唑啉基）噻吩7。后一种化合物可用作合成各种杂环的基础。根据新合成化合物的分析和光谱数据推导其结构。