New Efficient Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Catalyzed by Benzotriazolium-Based Ionic Liquids under Solvent-Free Conditions

Synthesis of dihydropyrimidinones via urea-based multicomponent reactions

Multicomponent reactions (MCRs) have emerged as powerful tools in organic chemistry, enabling the rapid and efficient assembly of complex molecular architectures. Urea-based multicomponent reactions have gained significant attention due to their versatility and broad applicability. In this review, we highlight recent developments in this area, with a focus on dihydropyrimidinones, and provide an in-depth analysis of the diverse synthetic pathways and applications of urea-based MCRs, shedding light on their fundamental mechanisms, reaction conditions, and potential for green and sustainable synthesis.

Magnetic BiFeO3 nanoparticles: a robust and efficient nanocatalyst for the green one-pot three-component synthesis of highly substituted 3,4-dihydropyrimidine-2(1H)-one/thione derivatives

In this research, magnetic bismuth ferrite nanoparticles (BFO MNPs) were prepared through a convenient method and characterized. The structure and morphological characteristics of the prepared nanomaterial were confirmed through analyses using Fourier-transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), elemental mapping, powder X-ray diffraction (XRD), N2 adsorption-desorption isotherms and vibrating sample magnetometry (VSM) techniques. The obtained magnetic BFO nanomaterial was investigated, as a heterogeneous Lewis acid, in three component synthesis of 3,4-dihydropyrimidin-2 (1H)-ones/thiones (DHPMs/DHPMTs). It was found that the BFO MNPs exhibit remarkable efficacy in the synthesis of various DHPMs as well as their thione analogues. It is noteworthy that this research features low catalyst loading, good to excellent yields, environmentally friendly conditions, short reaction time, simple and straightforward work-up, and the reusability of the catalyst, distinguishing it from other recently reported protocols. Additionally, the structure of the DHPMs/DHPMTs was confirmed through 1H NMR, FTIR, and melting point analyses. This environmentally-benign methodology demonstrates the potential of the catalyst for more sustainable and efficient practices in green chemistry.

Synthesis, Molecular docking, and in silico ADME Studies of Dihydropyrimidine Derivatives using Tetrabutylphosphonium Methanesulphonate Ionic Liquid as a catalyst Under Solvent Free Conditions

This paper describes the synthesis and characterization of tetrabutylphosphonium methanesulphonate ionic liquid and its use for the first time as a catalyst in multicomponent reaction for one-pot synthesis of Dihydropyrimidine derivatives from various aromatic aldehydes, methyl or ethyl acetoacetate and urea or thio-urea under the solvent-free conditions at 120 oC. About twenty-one different dihydropyrimidine derivatives have been synthesized in excellent yields. The advantage of this method is a solvent-free condition, the requirement of a small amount of catalyst, shorter reaction time, easy workup procedure and non-involvement of any hazardous organic solvent and toxic catalyst. This catalyst was easily prepared and showed excellent level of reusability. Also the molecular docking study was performed to evaluate interactions between the active compounds with Leishmania Pteridine reductase 1(PTR1). Further the theoretical evaluation of ADME properties in silico was investigated for their oral bioavailability to predict the safer efficacy of the synthesized compounds.

Biginelli Reaction Mediated Synthesis of Antimicrobial Pyrimidine Derivatives and Their Therapeutic Properties

Antimicrobial resistance was one of the top priorities for global public health before the start of the 2019 coronavirus pandemic (COVID-19). Moreover, in this changing medical landscape due to COVID-19, finding new organic structures with antimicrobial and antiviral properties is a priority in current research. The Biginelli synthesis that mediates the production of pyrimidine compounds has been intensively studied in recent decades, especially due to the therapeutic properties of the resulting compounds, such as calcium channel blockers, anticancer, antiviral, antimicrobial, anti-inflammatory or antioxidant compounds. In this review we aim to review the Biginelli syntheses reported recently in the literature that mediates the synthesis of antimicrobial compounds, the spectrum of their medicinal properties, and the structure-activity relationship in the studied compounds.

An Overview of Synthesis and Biological Activity of Dihydropyrimidine Derivatives

Dihydropyrimidine derivatives are most important scaffolds due to structure similarities with natural products it is a hetrocyclic compound. The chemistry of Dihydropyrimidine is a blossoming field. Various reaction schemes for the preparation of Dihydropyrimidines and produce different biological effect and offer vast scope in the field of medicinal chemistry. This article goal to analysis the work reported the recent chemistry and pharmacological activities of dihydropyrimidine derivatives.

Synthesis, cytotoxic assessment, and molecular docking studies of 2,6-diaryl-substituted pyridine and 3,4- dihydropyrimidine-2(1H)-one scaffolds

Cancer is one of the main global health problems. In order to develop novel antitumor agents, we synthesized 3,4-dihydropyrimidine-2(1H)-one (DHPM) and 2,6-diaryl-substituted pyridine derivatives as potential antitumor structures and evaluated their cytotoxic effects against several cancer cell lines. An easy and convenient method is reported for the synthesis of these derivatives, employing cobalt ferrite (CoFe 2 O 4 @SiO 2 -SO 3 H) magnetic nanoparticles under microwave irradiation and solvent-free conditions. The structural characteristics of the prepared nanocatalyst were investigated by FTIR, XRD, SEM, and TGA techniques. In vitro cytotoxic effects of the synthesized products were assessed against the human breast adenocarcinoma cell line (MCF-7), gastric adenocarcinoma (AGS), and human embryonic kidney (HEK293) cells via MTT assay. The results indicated that compound 4r (DHPM derivative) was the most toxic molecule against the MCF-7 cell line (IC 50 of 0.17 μg/mL). Moreover, compounds 4j and 4r (DHPM derivatives) showed excellent cytotoxic activities against the AGS cell line, with an IC 50 of 4.90 and 4.97 μg/mL, respectively. Although they are pyridine derivatives, compounds 5g and 5m were more active against the MCF-7 cell line. Results showed that the candidate compounds exhibited low cytotoxicity against HEK293 cells. The kinesin Eg5 inhibitory potential of the candidate compounds was evaluated by molecular docking. The docking results showed that, among the pyridine derivatives, compound 5m had the most free energy of binding (-9.52 kcal/mol) and lowest Ki (0.105 μM), and among the pyrimidine derivatives, compound 4r had the most free energy of binding (-7.67 kcal/mol) and lowest Ki (2.39 μM). Ligand-enzyme affinity maps showed that compounds 4r and 5m had the potential to interact with the Eg5 binding site via H-bond interactions to GLU116 and GLY117 residues. The results of our study strongly suggest that DHPM and pyridine derivatives inhibit important tumorigenic features of breast and gastric cancer cells. Our results may be helpful in the further design of DHPMs and pyridine derivatives as potential anticancer agents.

1, 1'-Sulfinyldiethylammonium Bis (Hydrogen Sulfate) as a Recyclable Dicationic Ionic Liquid Catalyst for the Efficient Solvent-free Synthesis of 3, 4-Dihydropyrimidin-2(1H)-ones via Biginelli Reaction

OBJECTIVE

A facile and efficient method for synthesis of 3, 4-dihydropyrimidin-2(1H)-ones via Biginelli reaction catalyzed by a novel dicationic Brönsted acidic ionic liquid, [(EtNH2)2SO][HSO4]2, has been successfully developed.

MATERIALS AND METHODS

3, 4-Dihydropyrimidin-2(1H)-ones were synthesized through one-pot condensation of aromatic aldehydes, ethyl acetoacetate, and urea under solvent-free conditions using [(EtNH2)2SO][HSO4]2 as a novel catalyst. The progress of the reaction was monitored by thin-layer chromatography (ethyl acetate / n-hexane = 1 / 5). The products have been characterized by IR, 1H NMR, 13C NMR, and also by their melting points.

RESULTS

In this research, a library of dihydropyrimidinone derivatives was synthesized via Biginelli reaction under solvent-free conditions at 120oC using [(EtNH2)2SO][HSO4]2 as a catalyst. Various aromatic aldehydes, as well as heteroaromatic aldehydes, were employed, affording good to high yields of the corresponding products and illustrating the substrate generality of the present method. In addition, the prepared dicationic Brönsted acidic ionic liquid can be easily recovered and reused.

CONCLUSION

1, 1'-Sulfinyldiethylammonium bis (hydrogen sulfate), as a novel dicationic ionic liquid, can act as a highly efficient catalyst for the synthesis of 3, 4-dihydropyrimidin-2(1H)-ones under solvent-free conditions.

Special Issue: "Organic Reactions in Green Solvents"

To overcome the well-established drawbacks of conventional organic solvents (toxicity, non-biodegradability, flammability, accumulation in the atmosphere) remarkable research efforts have been recently devoted to the replacement of traditional organic reaction media by the so-called Green Solvents. In this sense, the choice of a safe, non-toxic, biorenewable and cheap reaction media is a crucial goal in organic synthesis. Thus, this Special Issue on “Organic Reactions in Green Solvents” has been aimed to showcase a series of stimulating contributions from international experts within different sub-areas of organic synthesis in Green Solvents (ranging from metal- to organo-catalyzed organic reactions).