Regioselective synthesis and through-space 13C–19F spin–spin coupling NMR of new tetracyclic 3-(trifluoromethyl)-spiro(chromen[4,3-c]pyrazole-4,1′-cycloalkanes)
作者:Helio G. Bonacorso、Fábio D. Garcia、Chaiene R. Belo、Aniele Z. Tier、Clarissa P. Frizzo、Marcos A.P. Martins、Nilo Zanatta
DOI:10.1016/j.jfluchem.2014.07.011
日期:2014.10
for 24 h, a new series of seven examples of a new spiro-condensed heterocyclic system, namely 1(2)-methyl(phenyl)-3-(trifluoromethyl)-1,4(2,4)-dihydro-spiro(chromen[4,3-c]pyrazole-4,n′-cycloalkanes) – where cycloalkanes are cyclopentane, cyclohexane, and cycloheptane for n = 1; and tetrahydro-2H-pyran for n = 2 – were isolated at yields of between 35% and 51%. Finally, the structures of new spiro heterocycles
本文首先描述了一种有效的选择性和区域选择性方法,用于一个新的系列2,2,2-三氟-1- [4-甲氧基螺(2的合成ħ -苯并吡喃-2,1'-环烷烃)-3-基] ethanones从螺[苯并二氢吡喃-2,1'-环烷烃] -4-酮(Kabbe的加合物)。当从四个螺酮(Kabbe的加合物)得到的烯醇醚和/或缩醛的混合物的三氟乙酰化反应在45℃的温度下进行,得到的38-61%的产率,采用无水氯仿作为溶剂。随后,当三氟乙酰化的Kabbe加合物与苯肼和甲基肼在回流的乙醇中以1:1的摩尔比反应24小时时,新的七个螺环稠合杂环系统的新例子为1(2)-甲基(苯基)-3-(三氟甲基)-1,4-(2,4) -二氢-螺(苯并吡喃并[4,3-Ç ]吡唑-4,Ñ '环烷烃) - ,其中环烷烃是环戊烷,环己烷,和环庚烷为Ñ = 1; 和四氢-2- ħ吡喃为Ñ = 2 -分别以35%和51%之间的产率分离。最后,用辅助