Indazole is an important scaffold in medicinal chemistry. At present, the progress on synthetic methodologies has allowed the preparation of several new indazole derivatives with interesting pharmacological properties. Particularly, the antiprotozoal activity of indazole derivatives have been recently reported. Herein, a series of 22 indazole derivatives was synthesized and studied as antiprotozoals. The 2-phenyl-2H-indazole scaffold was accessed by a one-pot procedure, which includes a combination of ultrasound synthesis under neat conditions as well as Cadogan’s cyclization. Moreover, some compounds were derivatized to have an appropriate set to provide structure-activity relationships (SAR) information. Whereas the antiprotozoal activity of six of these compounds against E. histolytica, G. intestinalis, and T. vaginalis had been previously reported, the activity of the additional 16 compounds was evaluated against these same protozoa. The biological assays revealed structural features that favor the antiprotozoal activity against the three protozoans tested, e.g., electron withdrawing groups at the 2-phenyl ring. It is important to mention that the indazole derivatives possess strong antiprotozoal activity and are also characterized by a continuous SAR.

中文翻译：

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2-苯基-2H-吲唑衍生物的合成，抗原生动物活性和化学信息学分析

吲唑是药物化学中的重要支架。目前，合成方法学的进展已允许制备几种具有令人感兴趣的药理特性的新型吲唑衍生物。特别地，最近已经报道了吲唑衍生物的抗原生动物活性。在此，合成并研究了一系列22种吲唑衍生物作为抗原生动物。通过一锅法获得2-苯基-2 H-吲唑支架，该方法包括在纯净条件下超声合成以及Cadogan环化的组合。此外，某些化合物已衍生化为具有适当的一组化合物，以提供结构-活性关系（SAR）信息。而这些化合物中的六种对溶组织性大肠杆菌的抗原生动物活性，G。intestinalis和T.vaginalis先前已有报道，另外16种化合物的活性针对这些相同的原生动物进行了评估。生物学测定揭示了有利于对所测试的三种原生动物的抗原生动物活性的结构特征，例如2-苯基环上的吸电子基团。值得一提的是，吲唑衍生物具有很强的抗原生动物活性，并且具有连续SAR的特征。