Regioselectivity of N-substitution in bis-alkylation of 1,2,4-triazolo[1,5-a]benzimidazole-2-thione
| Autor: | Lyudmila N. Divaeva, Gennadii S. Borodkin, Tat’yana A. Kuz’menko, Anatolii S. Morkovnik, V. V. Kuz'menko |
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| Rok vydání: | 2012 |
| Předmět: |
chemistry.chemical_classification
Carbon disulfide Benzimidazole Base (chemistry) Stereochemistry Chemistry Substitution (logic) Regioselectivity General Chemistry Alkylation Medicinal chemistry chemistry.chemical_compound Density functional theory Two-dimensional nuclear magnetic resonance spectroscopy |
| Zdroj: | Russian Chemical Bulletin. 61:1161-1168 |
| ISSN: | 1573-9171 1066-5285 |
| DOI: | 10.1007/s11172-012-0158-7 |
| Popis: | Cyclization of the corresponding N-substituted 1,2-diaminobenzimidazoles with carbon disulfide in refluxing DMF leads to 3-methyl- and 3-benzyl-1,2,4-triazolo[1,5-a]benzimidazole-2-thiones. Based on the results of their S-alkylation, quantum chemical calculations by the density functional theory method, and 1D and 2D NMR spectroscopic studies, it was concluded that the bis-alkylation of N-unsubstituted 1,2,4-triazolo[1,5-a]benzimidazole-2-thione in the presence of a base proceeds with the formation of N(4)-derivatives of 2-alkylthio-1,2,4-triazolo[1,5-a]benzimidazole, rather than N(3)-derivatives as was believed earlier. |
| Databáze: | OpenAIRE |
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