An efficient synthetic route to construct diverse pyrazole-based chalcones from 1-phenyl-1H-pyrazol-3-ols bearing a formyl or acetyl group on the C4 position of pyrazole ring, employing a base-catalysed Claisen–Schmidt condensation reaction, is described. Isomeric chalcones were further reacted with N-hydroxy-4-toluenesulfonamide and regioselective formation of 3,5-disubstituted 1,2-oxazoles was established. The novel pyrazole-chalcones and 1,2-oxazoles were characterized by an in-depth analysis of NMR spectral data, which were obtained through a combination of standard and advanced NMR spectroscopy techniques.

中文翻译：

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1-Phenyl-1H-pyrazol-3-ol 合成新型杂环查耳酮及其表征

采用碱催化的 Claisen-Schmidt 缩合反应，从 1-苯基-1 H-吡唑-3-醇（在吡唑环的 C4 位上带有甲酰基或乙酰基）构建多种吡唑基查尔酮的有效合成途径是描述。异构查耳酮进一步与N-羟基-4-甲苯磺酰胺反应，并建立了3,5-二取代1,2-恶唑的区域选择性形成。新型吡唑查耳酮和 1,2-恶唑通过对 NMR 光谱数据的深入分析进行了表征，这些数据是通过标准和先进的 NMR 光谱技术相结合获得的。