Abstract—

Derivatives of 1,2,4-triazine-3-thione are interesting objects for study due to their wide range of application as medicinal drugs, substances with optoelectronic properties, and precursors for the synthesis of new pyridine systems by the Diels–Alder reaction. In this study, alkylation of 5-phenyl-2,3-dihydro-1,2,4-triazine-3-thione (1) with 3-chloro-2-methylprop-1-ene, 2,3-dibromoprop-1-ene, 1-bromo-3-methylbut-2-ene and 4-bromobut-1-ene yielded previously unknown 3-(2-methylprop-1-enyl)-, 3-(2-bromoprop-1-enyl)-, 3- prenylsulfanyl-, and 3-butenylsulfanyl-5-phenyl-1,2,4-triazines (2a–2d). The ¹H NMR spectrum of compound 2b showed a downfield shift of the SCH₂-group and the vinyl group proton signal by 0.48 and 0.60 ppm compared with similar signals in the spectrum of 3‑allylsulfanyl-5-phenyl-1,2,4-triazine. This may be due to the content of the bromine atom in the allyl fragment. The weakest signal in the ¹³C NMR spectra of compounds 2а–2d at 171.86–173.68 ppm belongs to the aromatic carbon atom of the triazine ring in the third position (C‑3) bonded to a sulfur atom and two nitrogen atoms. Using electrophilic heterocyclization of metallyl-, bromolyl-, prenyl-, and butenyl sulfides 2a–2d, the synthesis of new fused heterocyclic systems of the ionic type with a bridging nitrogen atom was carried out. At the same time, heterocyclization of the 2a, 2b compounds yielded [1,3]thiazolo[3,2-b][1,2,4]triazinium halides; heterocyclization of compounds 2c, 2d gave [1,3]thiazino[3,2-b][1,2,4]triazinium halides. The ¹H NMR spectra of triazinium halides show a characteristic downfield shift of the H-6 aromatic proton signal compared to the similar signal in the spectrum of the initial sulfides 2а–2d. The ¹³C NMR spectra of triazinium halides feature a shift of the signal of the aromatic carbon atom bonded to the sulfur atom and two nitrogen atoms (to the range of 162.56–172.42 ppm), which can be explained by the occurrence of a positively charged nitrogen atom in their structure.

中文翻译：

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碘、溴作用下3-烯基硫基-5-苯基-1,2,4-三嗪的合成及亲电杂环化

摘要-

1,2,4-三嗪-3-硫酮衍生物因其作为药物、具有光电特性的物质以及通过狄尔斯-阿尔德反应合成新吡啶系统的前体的广泛应用而成为令人感兴趣的研究对象。在本研究中，5-苯基-2,3-二氢-1,2,4-三嗪-3-硫酮 ( 1 ) 与 3-氯-2-甲基丙-1-烯、2,3-二溴丙-1 进行烷基化-ene、1-bromo-3-methylbut-2-ene 和 4-bromobut-1-ene 生成以前未知的 3-(2-methylprop-1-enyl)-、3-(2-bromoprop-1-enyl)- 、3-异戊二烯基硫基-和3-丁烯基硫基-5-苯基-1,2,4-三嗪( 2a–2d )。化合物2b的1 H NMR谱显示SCH _2的低^场位移与 3-烯丙基硫基-5-苯基-1,2,4-三嗪光谱中的类似信号相比，β-基团和乙烯基质子信号提高了 0.48 和 0.60 ppm。这可能是由于烯丙基片段中溴原子的含量所致。化合物2а-2d的¹³ C NMR谱中171.86-173.68 ppm处的最弱信号属于与硫原子和两个氮原子键合的三嗪环第三位(C-3)的芳香碳原子。利用金属硫化物、溴硫化物、异戊二烯硫化物和丁烯硫化物2a-2d的亲电杂环化，合成了具有桥接氮原子的新型离子型稠合杂环系统。同时，2a、2b的杂环化化合物产生[1,3]噻唑并[3,2- b ][1,2,4]三嗪卤化物；化合物2c、2d的杂环化得到[1,3]噻嗪基[3,2- b ][1,2,4]三嗪鎓卤化物。^{三嗪卤化物的 1} H NMR 谱显示，与初始硫化物2а–2d谱中的类似信号相比，H-6 芳香质子信号具有特征性的低场位移。^{三嗪鎓卤化物的13} C NMR谱的特点是与硫原子和两个氮原子键合的芳香碳原子的信号发生了偏移（范围为 162.56–172.42 ppm），这可以通过带正电荷的出现来解释。它们结构中的氮原子。