MnO₂ Nanoparticles as Efficient Oxidant for Ultrasound-Assisted Synthesis of 2-substituted Benzimidazoles under Mild Conditions

In this article, a novel method for synthesis of 2-substituted benzimidazoles using MnO₂ nanoparticles as a convenient oxidant agent in ethanol-water (1:1) as solvent under ultrasound irradiation was demonstrated. In this protocol the desired products were purely obtained in high yields. The main advantages of this research are: mild procedure, simplicity of method, easily work-up, high yields, and short reaction times. The MnO₂ nanoparticles were synthesized through a solid-state reaction route using simple strarting materials. Furthermore, their structure was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR).

本文报道了一种以二氧化锰（MnO₂）纳米颗粒为便捷氧化剂，以乙醇-水（体积比1:1）为溶剂，在超声辐照条件下合成2-取代苯并咪唑类化合物的新颖方法。该方法可高收率获得高纯度目标产物。本研究的主要优势如下：反应条件温和、操作简便、后处理容易、收率优异且反应时长较短。二氧化锰纳米颗粒通过固相反应路线，以简单起始原料合成得到。此外，通过X射线衍射（X-ray Diffraction, XRD）、扫描电子显微镜（Scanning Electron Microscopy, SEM）以及傅里叶变换红外光谱（Fourier Transform Infrared Spectroscopy, FT-IR）对其结构进行了表征。