Bentonite Supported NiTiO3 Composite as Heterogeneous Catalyst for Synthesis 2,4-Disubstituted Benzo[4,5]imidazo[1,2-a]pyrimidine

IF 2.3 4区化学 Q3 CHEMISTRY, PHYSICAL

Catalysis Letters Pub Date : 2025-04-17 DOI:10.1007/s10562-025-05016-6

Periasamy Vinoth Kumar, Selvaraj Mohana Roopan, Gunabalan Madhumitha

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引用次数: 0

Abstract

In this study, an eco-friendly synthesis of 2,4-disubstituted benzo [4,5]imidazo[1,2-a]pyrimidine analogs was developed using a microwave approach, utilizing Carissa edulis fruit extract stabilized NiTiO₃ nanoparticles decorated with a bentonite clay (NiTiO₃/bentonite) composite as an effective heterogeneous catalyst. A facile ultrasonication method was employed to prepare different loading of NiTiO₃/bentonite composites (5%, 10%, 15%, 20%, and 25%). Owing to its high surface area and active sites the NiTiO₃/bentonite composite was demonstrated to be an effective heterogeneous catalyst that provides high yields of 2,4-disubstituted benzo [4,5]imidazo[1,2-a]pyrimidine. The moderate surface area and active sites, chemical states, high thermal stability, and purity of the NiTiO₃/bentonite composites were confirmed using BET, XPS, TGA, XRD, and FT-IR. FE-SEM and elemental mapping were performed. HR-TEM analysis revealed that the NiTiO₃ nanoparticles had an aggregated spherical shape with an average particle size of 22 nm and a d-spacing of 0.21 nm. Various optimization parameters, including solvent, catalyst type, catalyst loading, temperature, microwave power was explored for synthesis of 2,4-disubstituted benzo [4,5]imidazo[1,2-a]pyrimidine. Mechanistic investigation reveals that initially, the aldehyde and ketone produce α, β-unsaturated ketone through Claisen-Schmidt condensation. Resulting intermediate reacts with 2-aminobenzimidazole followed by intramolecular cyclization and dehydrogenation process yielding the final product. The optimal NiTiO₃/bentonite catalyst achieved up to 94% yield with high turnover number and turnover frequency. Remarkably, the prepared heterogenous catalyst shows high catalytic activity, offering excellent yields even after six recycling cycles.

Graphical Abstract

NiTiO₃/Bentonite catalyst used Synthesis of 2,4-Disubstituted Benzo[4,5]imidazo[1,2-a]pyrimidine’s

查看原文本刊更多论文

膨润土负载NiTiO3复合材料合成2,4-二取代苯并[4,5]咪唑[1,2-a]嘧啶的非均相催化剂

本研究利用膨润土（NiTiO3/膨润土）复合材料修饰的Carissa edulis果实提取物稳定的NiTiO3纳米颗粒作为有效的非均相催化剂，利用微波法制备了2,4-二取代苯并[4,5]咪唑[1,2-a]嘧啶类似物。采用简易超声法制备不同负载率（5%、10%、15%、20%、25%）的NiTiO3/膨润土复合材料。由于具有较高的比表面积和活性位点，NiTiO3/膨润土复合材料被证明是一种有效的非均相催化剂，可以高产出2,4-二取代苯并[4,5]咪唑[1,2-a]嘧啶。通过BET、XPS、TGA、XRD、FT-IR等测试手段证实了NiTiO3/膨润土复合材料具有比表面积适中、活性位点适中、化学状态良好、热稳定性好、纯度高等特点。进行了FE-SEM和元素映射。hrtem分析表明，NiTiO3纳米颗粒呈球状聚集状，平均粒径为22 nm， d-间距为0.21 nm。考察了溶剂、催化剂类型、催化剂负载、温度、微波功率等优化条件对2,4-二取代苯并[4,5]咪唑[1,2-a]嘧啶的合成效果。机理研究表明，醛和酮最初通过Claisen-Schmidt缩合反应生成α， β-不饱和酮。所得到的中间体与2-氨基苯并咪唑反应，然后进行分子内环化和脱氢过程，得到最终产物。优化后的NiTiO3/膨润土催化剂转化率高达94%，转化率高，转化率高。值得注意的是，制备的多相催化剂具有较高的催化活性，即使经过六次循环也能获得优异的收率。用nitio3 /膨润土催化剂合成2,4-二取代苯并[4,5]咪唑[1,2-a]嘧啶

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来源期刊

Catalysis Letters 化学-物理化学

CiteScore

5.70

自引率

3.60%

发文量

327

审稿时长

1 months

期刊介绍： Catalysis Letters aim is the rapid publication of outstanding and high-impact original research articles in catalysis. The scope of the journal covers a broad range of topics in all fields of both applied and theoretical catalysis, including heterogeneous, homogeneous and biocatalysis. The high-quality original research articles published in Catalysis Letters are subject to rigorous peer review. Accepted papers are published online first and subsequently in print issues. All contributions must include a graphical abstract. Manuscripts should be written in English and the responsibility lies with the authors to ensure that they are grammatically and linguistically correct. Authors for whom English is not the working language are encouraged to consider using a professional language-editing service before submitting their manuscripts.