Reactions of 2-Mono- and 2,6-Disubstituted 4-Pyrones with Phenylhydrazine as General Method for the Synthesis of 3-(N-Phenylpyrazolyl)Indoles
作者:D. L. Obydennov、B. I. Usachev、V. Ya. Sosnovskikh
DOI:10.1007/s10593-014-1603-3
日期:2015.1
in protic and aprotic solvents, leading to phenylhydrazones of 3-(3-R-1-phenylpyrazol-5-yl)- or 3-(5-R-1-phenylpyrazol-3-yl)pyruvic acids (or esters), respectively. 6-Di(tri)fluoromethylcomanic acids (or esters) reacted analogously, forming the corresponding phenylhydrazones with RF group in the side chain. The obtained phenylhydrazones underwent Fischer reaction under acidic conditions, forming the
苯肼在质子和非质子溶剂中与6-取代的4-吡喃-2-羧酸(或酯)发生区域选择性反应,生成3-(3-R-1-苯基吡唑-5-基)-或3-(5 -R-1-苯基吡唑-3-基)丙酮酸(或酯)。6-二(三)氟甲基甲酸酯(或酯)类似地反应,形成具有R F的相应苯hydr组在侧链中。所得的苯Fi在酸性条件下进行费歇尔反应,形成各自的3-(N-苯基吡唑基)吲哚。与马来酸及其酯相反,2-取代的4-吡喃酮的反应非选择性地发生,并给出了区域异构的吡唑与侧链上的苯基hydr基团或3-(N-苯基吡唑基)吲哚的混合物。提出了一种机制来解释溶剂对反应过程的影响。