Mass Spectra of New Heterocycles: XXX. Study of 2-(Alkylsulfanyl)pyridines by Electron Ionization Mass Spectrometry

IF 0.9 4区 化学 Q4 CHEMISTRY, ORGANIC
L. V. Klyba, E. R. Sanzheeva, N. A. Nedolya, O. A. Tarasova
{"title":"Mass Spectra of New Heterocycles: XXX. Study of 2-(Alkylsulfanyl)pyridines by Electron Ionization Mass Spectrometry","authors":"L. V. Klyba,&nbsp;E. R. Sanzheeva,&nbsp;N. A. Nedolya,&nbsp;O. A. Tarasova","doi":"10.1134/S1070428025601669","DOIUrl":null,"url":null,"abstract":"<p>The behavior of a representative series of previously unknown 2-(alkylsulfanyl)pyridines, prepared starting from isothiocyanates, acetylene or allene carbanions, and alkylating agents via the intermediate formation and aromatization of 6-(alkylsulfanyl)-2,3-dihydropyridines, under electron ionization (70 eV) has been studied for the first time. All studied compounds formed stable molecular ions (<i>M</i><sup>+•</sup>, <i>I</i><sub>rel</sub> 21–100%). In most cases, the primary fragmentation pathway involved the loss of a hydrogen atom to give an [<i>M</i> – H]<sup>+</sup> ion. Moreover, for 3-ary(hetaryl)-substituted pyridines, except for 6-(vinyloxymethyl)-2-(methylsulfanyl)-3-phenylpyridine and 6-methyl-2-(methylsulfanyl)pyridine, this is the main fragmentation pathway. The other significant primary fragmentation pathways of the molecular ions of the synthesized compounds were associated with the fragmentation of the alkylsulfanyl group to form [<i>M</i> – Me]<sup>+</sup>, [<i>M</i> – SH]<sup>+</sup>, [<i>M</i> – SCH]<sup>+</sup>, [<i>M</i> – SCH<sub>2</sub>]<sup>+•</sup>, [<i>M</i> – SMe]<sup>+</sup>, or [<i>M</i> – SEt]<sup>+</sup> ions, depending on the nature and position of substituents in the pyridine ring. The introduction of a substituent (R, OR, SR), where R = Alk &gt; Me, into the pyridine molecule gives rise to a competing fragmentation pathway for the <i>M</i><sup>+•</sup> ion, associated with the loss of an alkene molecule. The fragmentation pathways of the molecular ions of 2-(alkylsulfanyl)pyridines with an OR substituent in the pyridine ring depends on whether the charge is localized on the oxygen or the sulfur atom. In the case of longer chain alkyl substituents (R = Bu, MeCHOEt), McLafferty rearrangement occurs along with simple bond cleavage. The fragment ions formed from the molecular ions of 3-aryl(hetaryl)pyridines are stabilized through the rearrangement into polycyclic aromatic structures that undergo little further fragmentation.</p>","PeriodicalId":766,"journal":{"name":"Russian Journal of Organic Chemistry","volume":"61 8","pages":"1427 - 1439"},"PeriodicalIF":0.9000,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Russian Journal of Organic Chemistry","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1134/S1070428025601669","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CHEMISTRY, ORGANIC","Score":null,"Total":0}
引用次数: 0

Abstract

The behavior of a representative series of previously unknown 2-(alkylsulfanyl)pyridines, prepared starting from isothiocyanates, acetylene or allene carbanions, and alkylating agents via the intermediate formation and aromatization of 6-(alkylsulfanyl)-2,3-dihydropyridines, under electron ionization (70 eV) has been studied for the first time. All studied compounds formed stable molecular ions (M+•, Irel 21–100%). In most cases, the primary fragmentation pathway involved the loss of a hydrogen atom to give an [M – H]+ ion. Moreover, for 3-ary(hetaryl)-substituted pyridines, except for 6-(vinyloxymethyl)-2-(methylsulfanyl)-3-phenylpyridine and 6-methyl-2-(methylsulfanyl)pyridine, this is the main fragmentation pathway. The other significant primary fragmentation pathways of the molecular ions of the synthesized compounds were associated with the fragmentation of the alkylsulfanyl group to form [M – Me]+, [M – SH]+, [M – SCH]+, [M – SCH2]+•, [M – SMe]+, or [M – SEt]+ ions, depending on the nature and position of substituents in the pyridine ring. The introduction of a substituent (R, OR, SR), where R = Alk > Me, into the pyridine molecule gives rise to a competing fragmentation pathway for the M+• ion, associated with the loss of an alkene molecule. The fragmentation pathways of the molecular ions of 2-(alkylsulfanyl)pyridines with an OR substituent in the pyridine ring depends on whether the charge is localized on the oxygen or the sulfur atom. In the case of longer chain alkyl substituents (R = Bu, MeCHOEt), McLafferty rearrangement occurs along with simple bond cleavage. The fragment ions formed from the molecular ions of 3-aryl(hetaryl)pyridines are stabilized through the rearrangement into polycyclic aromatic structures that undergo little further fragmentation.

Abstract Image

新杂环的质谱:XXX。电子电离质谱法研究2-(烷基磺酰)吡啶
本文首次研究了以异硫氰酸酯、乙炔或烯碳离子和烷基化剂为起始原料,在70 eV的电子电离条件下,6-(烷基磺酰)-2,3-二氢吡啶中间生成和芳构化制备的具有代表性的系列2-(烷基磺酰)吡啶的行为。所有化合物均形成稳定的分子离子(M+•,Irel 21-100%)。在大多数情况下,主要的断裂途径包括氢原子的损失,得到一个[M - H]+离子。此外,除了6-(乙烯氧基甲基)-2-(甲基磺胺基)-3-苯基吡啶和6-甲基-2-(甲基磺胺基)吡啶外,对于3-芳(乙基)取代吡啶来说,这是主要的断裂途径。根据取代基在吡啶环上的性质和位置,化合物分子离子的其他主要断裂途径与烷基磺酰基断裂形成[M - Me]+、[M - SH]+、[M - SCH]+、[M - SCH2]+•、[M - SMe]+或[M - SEt]+离子有关。在吡啶分子中引入取代基(R, OR, SR),其中R = Alk > Me,会引起M+•离子的竞争性断裂途径,并伴有烯烃分子的损失。具有OR取代基的2-(烷基磺胺基)吡啶分子离子的断裂路径取决于电荷是定位在氧原子上还是硫原子上。对于长链的烷基取代基(R = Bu, MeCHOEt), McLafferty重排伴随着简单的键裂解发生。由3-芳基(乙基)吡啶分子离子形成的片段离子通过重排形成多环芳香族结构而稳定下来,这种结构很少再发生碎片化。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
CiteScore
1.40
自引率
25.00%
发文量
139
审稿时长
3-6 weeks
期刊介绍: Russian Journal of Organic Chemistry is an international peer reviewed journal that covers all aspects of modern organic chemistry including organic synthesis, theoretical organic chemistry, structure and mechanism, and the application of organometallic compounds in organic synthesis.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:604180095
Book学术官方微信