Hydroxy chalcones undergo simple cyclizations with phenylhydrazine to afford 2-pyrazolines under microwave irradiation in the presence of glacial AcOH as cyclizing agent, also undergo simple cyclizations with hydroxylamine to afford 2-isoxazolines under microwave irradiation in the presence of KOH, and new cyclohexenone derivatives. Some valuable intermediates in the synthesis of fused heterocycles, have been prepared through K2CO3 which activate the cyclocondensation of hydroxychalcones with ethyl acetoacetate. The obtained results indicate that the microwave irradiation give shorter reaction times and cleaner reactions for synthesis of biologically important compounds.
羟基
查耳酮与
苯肼发生简单的环化反应,在以冰
乙醇为环化剂的微波辐照下生成 2-
吡唑啉;与
羟胺发生简单的环化反应,在以 KOH 为环化剂的微波辐照下生成 2-
异恶唑啉和新的
环己烯酮衍
生物。通过 K2CO3 激活羟基
查耳酮与
乙酰乙酸乙酯的环缩合,制备出了合成融合杂环的一些有价值的
中间体。研究结果表明,微波辐照可以缩短合成
生物重要化合物的反应时间,并使反应更清洁。