A facile and efficient approach for the direct thiocyanation of pyrazolin-5-ones via a radical mechanism has been established for the first time. A series of 4-thiocyanated 5-hydroxy-1H-pyrazoles were synthesized in fair to good yields by K₂S₂O₈-promoted direct thiocyanation of pyrazolin-5-ones with NH₄SCN at room temperature under simple and mild reaction conditions with atom- and step-economy and good functional group tolerance.

中文翻译：

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室温下用硫氰酸铵K2S2O8促进吡唑啉-5-酮的直接硫氰化

首次建立了一种通过自由基机理将吡唑啉-5-酮直接硫氰酸化的简便有效方法。在室温下，通过简单，温和的反应，通过K ₂ S ₂ O ₈促进吡唑啉-5-酮与NH ₄ SCN的直接硫氰化反应，合成了一系列4-硫氰酸化的5-羟基-1 H-吡唑，并以中等至良好的收率合成。具有原子经济和阶梯经济以及良好的官能团耐受性的条件。