Synthesis and Crystal Structures of 4,5-Dihydroimidazo[1,5-b]pyrazol-6-ones
| Autor: | Francisco Ródenas, Enrique Alarcón, José A. Sandoval, Antonio Guirado, María del Mar Sánchez Vera, Delia Bautista, Bruno Martiz |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
pyrazolines
Materials Science (miscellaneous) Hydrazine Chloral Crystal structure Pyrazole 010402 general chemistry Electrochemistry Ring (chemistry) 01 natural sciences Medicinal chemistry Catalysis Biomaterials imidazo-[1 5-b]pyrazolones lcsh:Chemistry chemistry.chemical_compound Hydrogen chloride heterocycles 010405 organic chemistry Organic Chemistry Aromatization 0104 chemical sciences acetophenones chemistry lcsh:QD1-999 chloral |
| Zdroj: | SynOpen, Vol 04, Iss 04, Pp 71-83 (2020) |
| ISSN: | 2509-9396 |
| DOI: | 10.1055/s-0040-1707304 |
| Popis: | The synthesis of previously unattainable 2,5-disubstituted 4,5-dihydroimidazo[1,5-b]pyrazol-6-ones has been developed. Electrochemical reductions of readily available 2,2,2-trichloroethylideneacetophenones were followed by reaction with hydrazine, leading to 3-aryl-5-dichloromethyl-2-pyrazolines. These were treated with isocyanates to obtain the corresponding aminocarbonyl derivatives, which were found to be able to form an otherwise almost inaccessible imidazo[1,5-b]pyrazole ring system via a one-step reaction involving internal condensation followed by hydrogen chloride elimination and aromatization. The molecular structures of 2-(4-methylphenyl)-5-tosyl-4,5-dihydroimidazo[1,5-b]pyrazol-6-one, 5-dichloromethyl-N-(4-chlorophenyl)-4,5-dihydro-3-p-tolylpyrazole-1-carboxamide, and 5-(4-bromophenyl)-2-p-tolyl-4,5-dihydroimidazo[1,5-b]pyrazol-6-one were determined by X-ray crystallographic analysis. |
| Databáze: | OpenAIRE |
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