One-pot synthesis of benzimidazole using DMF as a multitasking reagent in presence CuFe 2 O 4 as catalyst

One Pot Synthesis of New Benzimidazole Derivatives with Exceptionally High Luminescence Quantum Efficiency

AIM AND OBJECTIVES

There are different approaches to the synthesis of benzimidazole. In this article, five new benzimidazole derivatives, BMPO, Me-BMPO, Di-MeBMPO, F-BMPO and Cl-BMPO where (BMPO=3-[(1H)-benzo[d]imidazol-2-yl]pyridin-2(1H)-one), have been prepared. Another study was carried out on luminescence properties and their potential applications for the detection of transition metal ions.

MATERIALS AND METHODS

From the one-pot synthesis approach, all the derivatives of the benzimidazole compounds were obtained. The compounds were characterized using HRMS, 1HNMR, 13CNMR, and X-ray crystallography. Herein, a mechanism has been deciphered by predicting the release of HCl(g).

RESULTS

All compounds showed a strong deep blue emission when dissolved in dimethylacetamide (DMA), with emission wavelengths at 423, 428, 435, 423, and 421 nm, and half-times of 3.64, 2.77, 2, 19, 3.42 and 3.52 ns, respectively. In addition, their emission quantum yields were determined to be 72, 50, 42, 73 and 80%.

CONCLUSION

Five new benzimidazole derivatives, BMPO, Me-BMPO, Di-MeBIPO, F-BIPO, and Cl-BIPO, have been successfully synthesized by the one-pot synthesis method, and their structures are characterized and confirmed. The compounds exhibited exceptional luminescence by emitting a strong blue light in DMA with high fluorescence quantum yields between 42~80%.

Recent achievements in the synthesis of benzimidazole derivatives

Benzimidazoles are a class of heterocyclic compounds in which a benzene ring is fused to the 4 and 5 positions of an imidazole ring. Benzimidazole refers to the parent compound, while benzimidazoles are a class of heterocyclic compounds having similar ring structures, but different substituents. Benzimidazole derivatives possess a wide range of bioactivities including antimicrobial, anthelmintic, antiviral, anticancer, and antihypertensive activities. Many compounds possessing a benzimidazole skeleton have been employed as drugs in the market. The application of benzimidazoles in other fields has also been documented. The synthesis of benzimidazole derivatives has attracted much attention from chemists and numerous articles on the synthesis of this class of heterocyclic compound have been reported over the years. The condensation between 1,2-benzenediamine and aldehydes has received intensive interest, while many novel methods have been developed. In this article, we will give a comprehensive review of studies on the synthesis of benzimidazole, which date back to 2013. We have also tried to describe reaction mechanisms as much as we can. The work might be useful for chemists who work in the synthesis of heterocycles or drug chemistry.

Bimetallic Metal-Organic Framework Derived Nanocatalyst for CO2 Fixation through Benzimidazole Formation and Methanation of CO2

In this paper, a bimetallic Metal-Organic Framework (MOF) CoNiBTC was employed as a precursor for the fabrication of bimetallic nanoalloys CoNi@C evenly disseminated in carbon shells. These functional nanomaterials are characterized by powdered X-ray diffraction (PXRD), Fourier Transform Infra-Red spectroscopy (FTIR), surface area porosity analyzer, X-ray photoelectron spectroscopy (XPS), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Hydrogen Temperature-Programmed Reduction (H2 TPR), CO2 Temperature-Programmed Desorption (CO2-TPD), and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). This nanocatalyst was utilized in the synthesis of benzimidazole from o-phenylenediamine in the presence of CO2 and H2 in a good yield of 81%. The catalyst was also efficient in the manufacture of several substituted benzimidazoles with high yield. Due to the existence of a bimetallic nanoalloy of Co and Ni, this catalyst was also employed in the methanation of CO2 with high selectivity (99.7%).

One-Pot Domino Reaction: Direct Access to Polysubstituted 1,4-Benzothiazine 1,1-Dioxide via Water-Gas Shift Reaction Utilizing DMF/H2O

Benzothiazine 1,1-dioxide (BTDO) is a privileged chemical motif, and its metal-free domino access is in high demand. Current BTDO production methods require costly metal catalysts or harsh reaction conditions. A facile domino approach to BTDO via a water-gas shift reaction (WGSR) employing sodium 2-nitrobenzenesulfinates and α-bromo ketones is presented. This strategy is cost-effective and environmentally beneficial. The optimized reaction conditions demonstrated remarkable chemical tolerance to a wide range of electrically and sterically varied substituents on both coupling partners.

Insights into the structure and drug design of benzimidazole derivatives targeting the epidermal growth factor receptor (EGFR)

Tyrosine kinase overexpression could result in an unfavourable consequence of cancer progression in the body. A number of kinase inhibitor drugs targeting various cancer-related protein kinases have been developed and proven successful in clinical therapy. Benzimidazole is one of the most studied scaffolds in the search for effective anticancer drugs. The association of various functional groups and the structural design of the compounds may influence the binding towards the receptor. Despite numerous publications on the design, synthesis and biological assays of benzimidazole derivatives, their inhibitory activities against epidermal growth factor receptor (EGFR), a receptor tyrosine kinase (RTK), have not been specifically analysed. This review covers recent research reports on the anticancer activity of benzimidazole derivatives focusing on EGFR expression cell lines, based on their structure-activity relationship study. We believe it would aid researchers to envision the challenges and explore benzimidazole's potentials as tyrosine kinase inhibitors.

Recent advancements on Benzimidazole: A versatile scaffold in medicinal chemistry

Benzimidazole is nitrogen containing fused heterocycle which has been extensively explored in medicinal chemistry. Benzimidizole nucleus has been found to possess various biological activities such as anticancer, antimicrobial, anti-inflammatory, antiviral, antitubercular and antidiabetic. A number of benzimidazoles such as bendamustine, pantoprazole have been approved for the treatment of various illnesses whereas galeterone and GSK461364 are in clinical trials. The present review article gives an overview about the different biological activities exhibited by the benzimidazole derivatives as well as different methods used for the synthesis of benzimidazole derivatives for the past ten years.

Fabrication of Bimetal CuFe2O4 Oxide Redox-Active Nanocatalyst for Oxidation of Pinene to Renewable Aroma Oxygenates

This study report on the synthesis of spinel CuFe₂O₄ nanostructures by surfactant-assisted method. The catalysts were characterized by X-ray diffraction (XRD), laser Raman, transition electron microscope (TEM), scanning electron microscope (SEM), energy dispersive X-ray (EDX), hydrogen temperature programmed reduction (H₂-TPR), and Brunauer-Teller-Emmett-Teller (BET) surface area techniques. CuFe₂O₄ was active for pinene oxidation using tertiary butyl hydroperoxide (TBHP) to pinene oxide, verbenol, and verbenone aroma oxygenates. Under optimized reaction conditions, the spinel CuFe₂O₄ catalyst could afford 80% pinene conversion at a combined verbenol/verbenone selectivity of 76% within the reaction time of 20 h. The changes in catalyst synthesis solvent composition ratios induced significantly varying redox, phases, and textural structure features, which resulted in various catalytic enhancement effect. Characterization results showed the spinel CuFe₂O₄ catalyst possessing less than 5 wt% impurity phases, Cu(OH)₂, and CuO to afford the best catalytic performance. The CuFe₂O₄ catalyst was recyclable to up to five reaction cycles without loss of its activity. The recyclability of the bimetal CuFe₂O₄ oxide catalyst was simply rendered by use of an external magnet to separate it from the liquid solution.

Recent Uses of N,N-Dimethylformamide and N,N-Dimethylacetamide as Reagents

N,N-Dimethylformamide and N,N-dimethylacetamide are multipurpose reagents which deliver their own H, C, N and O atoms for the synthesis of a variety of compounds under a number of different experimental conditions. The review mainly highlights the corresponding literature published over the last years.

Beyond a solvent: triple roles of dimethylformamide in organic chemistry

N,N-Dimethylformamide (DMF) is frequently used as an aprotic solvent in chemical transformations in laboratories of academia as well as in those of chemical industry. In the present review, we will reveal that DMF is actually something much more than a solvent. It is a unique chemical since, as well as being an effective polar aprotic solvent, it can play three other important roles in organic chemistry. It can be used as a reagent, a catalyst, and a stabilizer.