The molecular mechanism of the rearrangement of 3-substituted 1-nitro-1H-pyrazoles into the corresponding 5-nitro-1H-pyrazoles was explored on the basis of the DFT computational study. It was found that these transformations proceed via two-step mechanism. The first step can be interpreted as [1,5]-sigmatropic NO₂ shift, whereas the second step can be interpreted as [1,5]-sigmatropic proton shift.

中文翻译：

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关于N-硝基吡唑重排的分子机理问题

在DFT计算研究的基础上，探索了3-取代的1-硝基-1 H-吡唑重排为相应的5-硝基-1 H-吡唑的分子机理。已发现这些转换通过两步机制进行。第一步可以解释为[1,5] -sigmatropic NO ₂位移，而第二步可以解释为[1,5] -sigmatropic质子位移。