Straightforward practical synthetic approaches to 3,4-bis- and 3,4,5-tris(trifluoromethyl)pyrazoles have been developed. The key step of the both syntheses is a transformation of the carboxylic group in a pyrazole core into the trifluoromethyl group by sulfur tetrafluoride. The elaborated synthetic protocols allow gram-scale preparation of the target products. The obtained compounds are comprehensively characterized by means of crystallographic analysis, determination of pK_a values and fluorescence measurements.

中文翻译：

---

“已报告，但仍未知。” 仔细研究3,4-双-和3,4,5-三（三氟甲基）吡唑

已经开发出简单易用的实用合成方法来合成3,4-双-和3,4,5-三（三氟甲基）吡唑。两种合成的关键步骤是通过四氟化硫将吡唑核中的羧基转化为三氟甲基。详细的合成方案可实现目标产品的克级制备。通过晶体学分析，p K _a值的测定和荧光测量来全面表征获得的化合物。