A green, rapid, and efficient methodology is developed for the synthesis of 1‐phenyl‐3,5‐pyrazolidinedione (3) by the reaction of malonic acid with phenyl hydrazine in the presence of phosphorous oxychloride under solvent‐free conditions. The later compound 3 was used as a versatile precursor for green synthesis of chalcone derivatives (4a‐h) and spiroheterocyclic compounds (5a‐h) with good to excellent isolated yields. The chemical structures of the synthesized compounds were elucidated on the basis of elemental and spectral analyses.

中文翻译：

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绿色合成研究和一些基于螺吡唑烷的具有潜在生物活性的杂环的光谱表征

开发了一种绿色，快速，有效的方法，用于在无溶剂条件下，通过丙二酸与苯基肼在氯氧化磷存在下的反应，来合成1-苯基-3,5-吡唑烷二酮（3）。后来的化合物3用作绿色合成查尔酮衍生物（4a-h）和螺杂环化合物（5a-h）的通用前体，具有良好的分离产率。在元素分析和光谱分析的基础上阐明了合成化合物的化学结构。