Methyl Carbonium Ion Migration during the Reaction of 4-Chloro-5-methoxyl-3(2H)-pyridazinone with Trifluoroethylation Agents

To synthesize 4-chloro-5-methoxy-2-(β-trifluoroethyl)-3(2H)-pyridazinone (4), the reactions of 4-chloro-5-methoxy-3(2H)-pyridazinone (5) with RCH(2)CF(3) (R = I, TsO, MsO, TfO) in different solvents were studied. It was found that methyl group migration took place during this reaction. An oxonium sa...

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Detalles Bibliográficos
Autores principales: Li, Qin, Lin, Guichun, Liu, Li, Yang, Zhenjun, Zhang, Li-He
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Molecular Diversity Preservation International 2009
Materias:
Article
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6253874/
https://www.ncbi.nlm.nih.gov/pubmed/19223826
http://dx.doi.org/10.3390/molecules14020777
Descripción
Sumario:To synthesize 4-chloro-5-methoxy-2-(β-trifluoroethyl)-3(2H)-pyridazinone (4), the reactions of 4-chloro-5-methoxy-3(2H)-pyridazinone (5) with RCH(2)CF(3) (R = I, TsO, MsO, TfO) in different solvents were studied. It was found that methyl group migration took place during this reaction. An oxonium salt 9 was suggested as the active intermediate for the formation of the byproduct 4-chloro-5-methoxy-2-methyl-3(2H)-pyridazinone (7) and 4-chloro-2-methyl-5-(β-Trifluoroethoxy)-3(2)-pyridazinone (8).

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