Ацилювання індолілзаміщених β-кетонітрилів. Шлях до нових похідних індоло[2,3-c]пірилію та β-карболіну
Aim. To synthesize 4-cyanoindolo[2,3-c]pyrilium salts and examine their reactivity towards N-nucleophiles.Results and discussion. The acylation reaction of 2-(indolyl-3)-2-aroylacetonitriles under acid catalysis conditions was studied. 4-Cyanoindolo[2,3-c]pyrillium borofluorides were obtained, and k...
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| Datum: | 2020 |
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| Hauptverfasser: | , , |
| Format: | Artikel |
| Sprache: | Ukrainian |
| Veröffentlicht: |
National University of Pharmacy
2020
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| Online Zugang: | https://ophcj.nuph.edu.ua/article/view/ophcj.20.206021 |
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| Назва журналу: | Journal of Organic and Pharmaceutical Chemistry |
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Journal of Organic and Pharmaceutical Chemistry| Zusammenfassung: | Aim. To synthesize 4-cyanoindolo[2,3-c]pyrilium salts and examine their reactivity towards N-nucleophiles.Results and discussion. The acylation reaction of 2-(indolyl-3)-2-aroylacetonitriles under acid catalysis conditions was studied. 4-Cyanoindolo[2,3-c]pyrillium borofluorides were obtained, and ketonitrile enolacylates were isolated as by-products of the reaction. Treatment of the 4-cyanoindolo[2,3-c]pyrilium salts with ammonia led to 4-cyano-β-carbolines while the interaction of the salts with hydrazine hydrate resulted in formation of pyrazolo[3’,4’:5,6]pyrido[3,4‑b]indoles – derivatives of a new heterocyclic system. The latter are formed via recyclization involving the pyran ring and the cyano group.Experimental part. Upon the treatment of 2-(indolyl-3)-2-aroylacetonitriles with acetic anhydride/tetrafluoroboric acid mixture, the acylation of the indole fragment in position 2 was followed by cyclization, resulting in formation of 4-сyanoindolo[2,3-c]pyrilium salts. The reactivity of the pyrylium salts was studied on the examples of their interaction with N-nucleophiles – ammonia and hydrazine hydrate. The structure of the compounds synthesized was confirmed by 1H NMR, IR spectroscopy and elemental analysis.Conclusions. It has been found that moderate yields of 4-сyanoindolo[2,3-c]pyrilium salts are the result of competing acylation of the hydroxyl group of enol ketonitrile, which blocks the pyran ring formation. Recylization of the salts with ammonia leads to 4-cyano-β-carbolines. Transformation of the pyran ring with hydrazine hydrate proceeds with the participation of the cyano group as a tandem reaction with formation of pyrazolo[3’,4’:5,6]pyrido[3,4-b]indoles.Received: 22.06.2020 Revised: 03.10.2020 Accepted: 23.10.2020 |
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