A Divergent Synthesis of Spiropyrazole Derivatives Containing Iminolactone and/or Cyclic Imide Moiety
作者:Eiichi Masumoto、Hiroshi Maruoka、Fumi Okabe、Toshihiro Fujioka、Kenji Yamagata
DOI:10.1002/jhet.1946
日期:2015.1
approach to spiropyrazole derivatives containing iminolactone and/or cyclic imide moiety starting from 1H‐pyrazole‐4‐acetic acid derivative is described. Hydrolysis of C‐cyanomethylated 1H‐pyrazole‐4‐acetic acid methyl ester (1), which was easily prepared from 1H‐pyrazole‐4‐acetic acid derivative by a C‐cyanomethylation, led to the C‐cyanomethylated 1H‐pyrazole‐4‐acetic acid (2). Compound 2 was reacted
描述了一种从1 H-吡唑-4-乙酸衍生物开始的,包含亚氨基内酯和/或环状酰亚胺部分的螺并吡唑衍生物的方法。的水解Ç -cyanomethylated 1个ħ吡唑-4-乙酸甲酯(1),将其容易地从1个制备ħ吡唑-4-乙酸衍生物通过Ç -cyanomethylation,导致Ç -cyanomethylated 1 ħ -吡唑-4-乙酸(2)。在回流的氯仿中,在氯化锡(Ⅳ)的存在下,使化合物2与乙醇反应,得到关键的中间体亚氨酸乙酯(3)。在N,N-二甲基甲酰胺中进行3的氢化钠辅助内酯化,得到含有亚氨基内酯部分的螺吡唑衍生物(4)。另一方面,在不存在溶剂的情况下用乙酸钠对3进行热处理导致另一分子内环化,从而产生含有环酰亚胺部分的螺并吡唑衍生物(6)。