Synthesis of alkynyl-substituted pyrrole and 1,4-thiazepine derivatives

Yılmaz, Elif Serel
Heterocyclic compounds have a great importance in medicinal chemistry because of their presence in a number of pharmaceuticals. Among them, pyrroles and 1,4-thiazepines play a vital role in pharmaceutical chemistry because of their presence in a number of bioactive molecules and natural products. For this reason, the development of new synthetic methods for the synthesis of these compounds has attracted much attention. Recently, the cyclization of functionally-substituted alkynes has emerged as a valuable tool in the preparation of various heterocyclic and carbocyclic compounds. In this regard, N-propargylic β-enaminones have proven to be useful. In this study, we have anticipated that the cyclizations of N-(2,4-pentadiynyl)-β-enaminones would produce biologically important alkynyl-substituted pyrrole and 1,4-thiazepine derivatives. In the first part of this study, we have shown that conjugate addition of propargylamine to α,β-alkynic ketones followed by the coupling of the resulting N-propargylic β-enaminones with terminal alkynes, yields N-(2,4-pentadiynyl)-β-enaminones. When treated with a base such as sodium hydride, N-(2,4-pentadiynyl)-β-enaminones afforded alkynyl-substituted pyrrole derivatives. In the second part of this study, we have shown that when treated with Lawesson’s reagent, β-enaminones produced in situ N-(2,4-pentadiynyl)-β-enaminothiones that underwent intramolecular cyclization immediately to afford 2-(2-propyn-1-ylidene)-2,3-dihydro-1,4-thiazepines in good yields in one-pot manner. In conclusion, 7 novel alkynyl-substituted pyrrole and 12 novel 1,4-thiazepine derivatives were synthesized.


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Synthesis of five-membered heteroaromatic compounds such as pyrazoles, isoxazoles and 1,2,4-oxadiazoles are important for pharmaceutical industry and material science due to their applications. Although there are many methods to prepare such compounds, new variants continue to appear since they exhibit a wide range of biological and medicinal activities. In this thesis, new methods were developed for the synthesis of 4-iodopyrazoles, pyrazoles, isoxazoles, 1,2,4-oxadiazoles and/or 1,2,4-oxadiazepines. In th...
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Heterocyclic fused compounds have gained considerable attention for pharmaceutical applications since they show remarkable biological activities such as antitumor and/or anticancer activities. In particular, the synthesis of seven-membered ring embedded molecules is a challenging issue among organic chemists. Therefore, we have aimed to develop one-pot reaction for the synthesis of seven-membered-fused heterocyclic compounds. We have developed a new methodology for the synthesis of pyrrolo[2',1':3,4]quinoxa...
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Kanova, Nilay; Zora, Metin; Department of Chemistry (2020)
Heterocyclic compounds are a momentous area of synthetic organic chemistry because of their existence in bioactive molecules. Pyrroles, which are one of the most important classes of heterocyclic compounds, have great importance in pharmaceutical chemistry due to their biological activities. Having these characteristics makes them drawn attention of most chemists to develop new methodologies for the synthesis of pyrroles. Recently, the cyclization of Npropargylic β-enaminones has been used for the synthesis...
Synthesis of highly substituted alkynylpyridines and development of new methodologies for the synthesis of 1,4-oxazepines, 1,4-thiazepines and 5-methylpyridines /
Kelgökmen, Yılmaz; Zora, Metin; Department of Chemistry (2018)
Convenient syntheses of pyridines, 1,4-oxazepines and 1,4-thiazepines have become an important research area among organic chemists since they constitute scaffolds of many medicinal substances. Recently, N-propargylic β-enaminones have been widely used for the facile synthesis of potent biologically active heterocycles. Many research groups have focused on the proper synthesis of various heterocycles by using N-propargylic β-enaminones. One of the such recent reports using these precursors is the formation ...
Synthesis of 6-halogen-substituted 2-methylene-2,3dihydro-1,4-oxazepine derivatives
İbiş, Özge; Zora, Metin; Department of Chemistry (2017)
Heterocyclic compounds are important since they are present in life naturally or synthetically. Among heterocyclic compounds, seven-membered 1,4-oxazepines are giving more attention than ever due to their wide range of biological and medicinal activities. There are many studies about their synthesis and new ones continue to appear. In this study, synthesis of halogen-substituted 1,4-oxazepine derivatives was investigated, which may have potential for biological studies. For this purpose, α,β-alkynic ketone ...
Citation Formats
E. S. Yılmaz, “Synthesis of alkynyl-substituted pyrrole and 1,4-thiazepine derivatives,” M.S. - Master of Science, Middle East Technical University, 2018.