Abstract In this study, Fe3O4@urea/HITh-SO3H MNPs as a new, efficient, and recyclable solid acid magnetic nanocatalyst was synthesized and characterized using various methods including Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, energy-dispersive X-ray spectroscopy, and X-ray powder diffraction. After the characterization of this new magnetic nanocatalyst, it was efficiently utilized for the promotion of the one-pot synthesis of 7-aryl-8H-benzo[h]indeno[1,2-b]quinoline-8-one and indeno[2′,1′:5,6]pyrido[2,3-d]pyrimidine derivatives via three-component reaction of the 1,3-indanedione, aldehyde, and 1-naphthylamine/1,3-dimethyl-6-aminouracil under solvent-free conditions at 80°C. The procedure gave the desired heterocyclic structures in high-to-excellent yields and short reaction times. Also because of the magnetic nature of the nanocatalyst, it can be separated with an external magnetic field and reused at least six runs without any considerable decrease in the catalytic behavior.

中文翻译：

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Fe3O4@urea/HITh-SO3H作为一种高效且可重复使用的催化剂，用于无溶剂合成7-芳基-8H-苯并[h]茚并[1,2-b]喹啉-8-酮和茚并[2',1] ':5,6]吡啶并[2,3-d]嘧啶衍生物

摘要 本研究采用傅里叶变换红外光谱、热重分析、扫描电子显微镜、透射电子显微镜、振动分析等多种方法合成并表征了 Fe3O4@urea/HITh-SO3H MNPs 作为一种新型、高效、可回收的固体酸性磁性纳米催化剂。样品磁力测定、能量色散 X 射线光谱和 X 射线粉末衍射。在表征这种新型磁性纳米催化剂后，它被有效地用于促进7-芳基-8H-苯并[h]茚并[1,2-b]喹啉-8-one和茚并[2]的一锅法合成',1':5,6]吡啶并[2,3-d]嘧啶衍生物通过1,3-茚二酮、醛和1-萘胺/1,3-二甲基-6-氨基尿嘧啶在溶剂下的三组分反应- 80°C 的自由条件。该程序以高到极好的收率和短反应时间提供了所需的杂环结构。同样由于纳米催化剂的磁性，它可以用外部磁场分离并重复使用至少六次，而催化行为没有任何显着降低。