3(5)-(2-Hydroxyphenyl)-5(3)-styrylpyrazoles: Synthesis and Diels?Alder Transformations
作者:Vera�L.�M. Silva、Artur�M.�S. Silva、Diana�C.�G.�A. Pinto、Jos�A.�S. Cavaleiro、Jos� Elguero
DOI:10.1002/ejoc.200400407
日期:2004.11
Reactions between cinnamoyl(2-hydroxybenzoyl)methanes and hydrazine hydrate in acetic acid gave 3-(2-hydroxyphenyl)-5-styrylpyrazoles, while the corresponding reactions with phenylhydrazine yielded 5-(2-hydroxyphenyl)-1-phenyl-3-styrylpyrazoles as the major products and 3-(2-hydroxyphenyl)-1-phenyl-5-styrylpyrazoles as by-products. The reaction mechanism of this transformation is discussed. The first
肉桂酰(2-羟基苯甲酰基)甲烷与水合肼在乙酸中反应生成 3-(2-羟基苯基)-5-苯乙烯基吡唑,而与苯肼的相应反应生成 5-(2-羟基苯基)-1-苯基-3-苯乙烯基吡唑主要产物为3-(2-羟基苯基)-1-苯基-5-苯乙烯基吡唑类为副产物。讨论了这种转变的反应机理。邻苯并醌二甲烷与 3-(2-羟基苯基)-5-苯乙烯基吡唑或 5-(2-羟基苯基)-1-苯基-3-苯乙烯基吡唑之间的第一次环加成反应得到 5-[2-(3-芳基-1, 2,3,4-四氢萘基)]-3-(2-羟基苯基)吡唑或3-[2-(3-芳基-1,2,3,4-四氢萘基)]-1-苯基-5-(2-羟基苯基)吡唑,分别。这些环加合物通过在干燥的 1,4-二恶烷中用 DDQ 氧化转化为相应的萘基吡唑。所有新衍生物的结构都已通过核磁共振光谱确定。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim