Unexpected Formation of Bis(hydrazinecarboximidamide) via Ultrasound Promoted Rearrangement of Epoxy Ketone
An efficient synthesis of aromatic pyrazoles via cyclocondensation of epoxy chalcones with hydrazine is reported. When aminoguanidine hydrochloride is the dinucleophilic specie the reaction leads to a mixture of amidino pyrazole and a minor amount (15%) of an interesting co-product identified as 2,2...
| Autores: | , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | Brasil |
| Recursos: | Universidade Federal de Mato Grosso do Sul (UFMS) |
| Repositorio: | Orbital - The Electronic Journal of Chemistry (Campo Grande) |
| Idioma: | inglés |
| OAI Identifier: | oai:periodicos.ufms.br:article/16499 |
| Acesso em linha: | https://periodicos.ufms.br/index.php/orbital/article/view/16499 |
| Access Level: | acceso abierto |
| Palavra-chave: | α,β-epoxy ketones pyrazoles ultrasound unexpected reaction |
| Resumo: | An efficient synthesis of aromatic pyrazoles via cyclocondensation of epoxy chalcones with hydrazine is reported. When aminoguanidine hydrochloride is the dinucleophilic specie the reaction leads to a mixture of amidino pyrazole and a minor amount (15%) of an interesting co-product identified as 2,2'-(1,3-diphenylpropane-1,2-diylidene)bis(hydrazinecarboximidamide) dihydrochloride by X-ray diffraction and NMR. A plausible mechanism for the co-product formation via rearrangement of the epoxy chalcone into 1,2-diketone followed by the condensation with aminoguanidine reaction is proposed. DOI: http://dx.doi.org/10.17807/orbital.v9i3.972 |
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