Addition reaction of azoles to acetone-d6: NMR and computational studies

The reactivity of imidazole, pyrazole, 1,2,4-triazole, 1,2,3-triazole, and tetrazole with acetone (propan-2-one) has been studied by 1H and 13C NMR using acetone-d6 as solvent at temperatures ranging from 173 to 300 K at 10 K intervals. Simultaneously, the reaction has been theoretically calculated...

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Detalles Bibliográficos
Autores: Claramunt, Rosa M., Sanz, Dionisia, Alkorta, Ibon, Elguero, José
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/369533
Acceso en línea:http://hdl.handle.net/10261/369533
Access Level:acceso abierto
Palabra clave:acetone addition
imidazole
tetrazole
pyrazole
triazoles
DFT calculations
DNMR
annular tautomerism
Descripción
Sumario:The reactivity of imidazole, pyrazole, 1,2,4-triazole, 1,2,3-triazole, and tetrazole with acetone (propan-2-one) has been studied by 1H and 13C NMR using acetone-d6 as solvent at temperatures ranging from 173 to 300 K at 10 K intervals. Simultaneously, the reaction has been theoretically calculated at the B3LYP/6-311++G(d,p) level, and experimental and theoretical results have been compared. The equilibrium constants between azoles and adducts α,α-dimethyl-azole-methanol were analyzed, assuming that the straight part of the plots –R ln Ke vs. 1/T can be used to determine ΔH and ΔS. Calculated and experimental data are related, but the theoretical values are proportionally higher. The tautomerism of triazoles and tetrazole has been considered in order to discuss the reactions.