Reaction of 3-(polyfluoroacyl)chromones with hydrazines: new regioselective synthesis of RF-containing pyrazoles
作者:V. Ya. Sosnovskikh、R. A. Irgashev、V. S. Moshkin、M. I. Kodess
DOI:10.1007/s11172-008-0291-5
日期:2008.10
Reactions of 3-(polyfluoroacyl)chromones with hydrazine, methyl-and phenylhydrazines proceed by the mechanism of nucleophilic 1,4-addition with subsequent pyrone ring opening and heterocyclization at the polyfluoroacyl group to 4-(2-hydroxyaroyl)-3-polyfluoro-alkylpyrazoles or at the aroyl group to 4-polyfluoroalkyl-2,4-dihydrochromeno[4,3-c]pyrazol-4-ols. Regiochemistry of the products was established
3-(多氟酰基)色酮与肼、甲基-和苯肼的反应通过亲核 1,4-加成机制进行,随后吡喃酮开环和多氟酰基杂环化为 4-(2-羟基芳酰基)-3-多氟-烷基吡唑或在芳酰基到 4-多氟烷基-2,4-二氢色基[4,3-c]吡唑-4-醇。产品的区域化学是基于二维实验 HSQC、HMBC 和 NOESY 和 X 射线衍射研究的数据建立的。