One-pot Multicomponent Reaction Research Articles

Acid-Mediated Multicomponent Domino Reaction for the Synthesis of N-substituted Isoindolinones

A one-pot multicomponent reaction of 2-carboxy-benzaldehyde, nitrile/aniline and a nucleophile (N, N- disubstituted aniline) generated a variety of functionalized N-substituted isoindolinone derivatives. The metal-free intramolecular cyclization reaction furnished products in good to excellent yields across various substrates. This environmentally friendly multi-component reaction offers a sustainable method for synthesizing a diverse library of N-substituted isoindolinone derivatives under acidic conditions. The cascade reaction triggers formation of a C-C and two C-N bonds involving carbonyl and carboxyl groups in the presence of nitrile/aniline. Additionally, in the absence of nitrogen source, 3-substituted isobenzofuran-1(3H)-ones were synthesized.

Facile one-pot synthesis of N-pyridinylaminonaphthol derivatives and their antibacterial evaluation against multidrug-resistant Staphylococcus aureus.

The escalating severity of the menace posed by bacterial resistance has rendered the existing antibiotics less effective, thus necessitating the discovery of new antibacterial agents. The current study reports the exploration of substituted N-pyridinylaminonaphthols produced by a straightforward, one-pot multicomponent reaction process as antibacterial agents. The synthesized derivatives were assessed in vitro for their antibacterial properties against a panel of bacterial pathogens. The analogs 4b, 4g, 4h, 4i, 4j, 4l, 4r, and 4t exhibited potent inhibitory activity with minimum inhibitory concentration (MIC) values of 1-2 µg/mL. Notably, 4b, 4l, and 4t displayed an excellent selectivity index. Additionally, they were active against the multidrug-resistant bacterial strains, with 4l exhibiting the best activity against methicillin-resistant Staphylococcus aureus and vancomycin resistant staphylococcus aureus with a MIC of 1 µg/mL. 4l showed synergism with gentamycin and showed bactericidal property in a concentration-dependent manner. Furthermore, the molecule 4l inhibited the DNA gyrase supercoiling activity. Absorption, distribution, metabolism, excretion/toxicity parameters and pharmacokinetic properties were assessed via in silico techniques, which elucidate the potential mode of action. These findings demonstrate the potential of the N-pyridinylaminonaphthol derivatives as antibacterial agents against multidrug-resistant S. aureus.

Green Chemistry and In silico Techniques for Synthesis of Novel Pyranopyrazole and Pyrazolo-pyrano-pyrimidine Derivatives as Promising Antifungal Agents.

Every year Invasive Fungal Infections (IFI) are globally affecting millions of people. Candida albicans and Aspergillus niger have been reported as the most infectious and mortality-inducing fungal strains among all pathogenic fungi. To tackle this problem in the current study Pyranopyrazoles and Pyrazolopyrano- pyrimidine derivatives were developed using molecular hybridization, green chemistry and one-pot multicomponent reaction. In the present work, New Chemical entities (NCE's) were developed on the basis of Structure activity relationship. All designed NCE's were screened for ADMET studies using the QikProp module of Schrodinger software. NCE's with zero violations were further docked on the crystal structure of 14α demethylase, cytochrome P450 and thymidine synthase (PDB ID: 5V5Z, 7SHI, 1BID). Selected molecules were synthesized using green chemistry techniques and evaluated for in vitro antifungal activity against Candida albicans and Aspergillus niger. Designed NCE's (B1-12 and C1-11) showed favorable results in ADMET studies. In the docking study six compounds from series-B and five molecules from series- C showed good dock score and binding interaction when compared with the standard drugs. Compounds B-3 and C-4 showed the highest zone of inhibition activity against Candida albicans, where as B-1 and C-3 had shown highest zone of inhibition activity against Aspergillus niger. Bicyclic ring (series B) showed better activity as compare to fused tricyclic ring (series C).

Ni-Fe2O3@SiO2-Pr-DBU: A novel efficient magnetically retrievable catalyst for one-pot synthesis of dihydropyrano [3,2-c] chromene

In the present work, Ni-Fe2O3@SiO2-Pr-DBU was synthesized as a novel magnetically separable nano-catalyst and characterized by various techniques like Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM), Vibrating-sample magnetometry (VSM), Transmission electron microscopy (TEM) and Elemental analysis by energy dispersive X-ray (EDX). The catalytic efficiency of NiFe2O3@SiO2-Pr-DBU was explored in the synthesis of dihydropyrano[3,2-c] chromenes through a one-pot multicomponent reaction of 4-hydroxycoumarin, malononitrile, and aryl aldehydes in aqueous solution at ambient temperature condition. An external magnet easily removed the nano-sized magnetic core catalyst from the synthesized reaction mixture. It was recycled for five successive runs while maintaining its potential and adhering to our green synthesis approach. We used dihydropyrano chromene, a highly biologically active commercial compound, to prepare some novel derivatives.

Green Synthesis and Evaluation of the Biological Activity of New Dihydropyridine Derivatives.

This work used silica-coated magnetic nanoparticles functionalized by iminodiacetic acid-cupper (Fe3O4@SiO2/IDA-Cu) to perform one-pot multicomponent reactions involving (1E,6E)-1,7-Bis(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5-dione (curcumine), primary amines, and activated acetylenic compounds in an aqueous medium at room temperature and to produce 1,4- dihydropyridine-2,3-dicarboxylate in high yields. Further research on this area uses diphenylpicrylhydrazine (DPPH) radical trapping to investigate the antioxidant properties of some generated 6,6´- methylene bis-1,4-dihydropyridine-2,3-dicarboxylates. Scholarly research now underway concentrates on examining the antibacterial characteristics of chemical substances that have been produced. The reagents or solvents that the research team utilized were of analytical quality, which means that their physical and chemical characteristics were unaltered. The Ft-IR spectra of the prepared nanocatalysts and the synthesized 6,6´-methylene bis-1,4-dihydropyridine-2,3-dicarboxylates in a KBr medium were recorded using a Shimadzu IR-460 spectrometer. In addition, a Bruker DRX-400 AVANCE spectrometer was used to get the 1H and 13C NMR spectra of the produced compounds. To get the spectrum of the compounds generated, the spectrometer was calibrated to 400 MHz, the solvent was CDCl3, and the internal standard was TMS. It should be mentioned that the mass spectra of the generated compounds, which have an ionization capability of 70 eV, were obtained using the Finnigan MAT 8430 spectrometer. Using spectroscopy investigation, including X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM), the synthetic catalyst Fe3O4@SiO2@IDA-Cu was approved for construction. Finnigan-MAT 8430 spectrometer was used to generate mass spectra of the chemicals that were created. To determine which element was present in the compounds that were formed, the Heraeus CHN-O-Rapid analyzer was used. The current study focused on creating new 6,6´-methylene bis-1,4-dihydropyridine-2,3- dicarboxylates 4 by combining curcumine 1, primary amines 2, and activated acetylenic compounds 3 in three-component processes. The reactions were performed in a water-based solution at normal ambient temperature, using Fe3O4@SiO2@IDA-Cu as a nanocatalyst that may be used multiple times. The findings demonstrated that the synthesized compounds displayed a significant antioxidant potential in comparison to conventional antioxidants. Furthermore, the produced compounds were evaluated for their antibacterial efficacy against both gram-positive and gram-negative bacteria. In conclusion, the multicomponent reactions involving curcumin, primary amines, and activated acetylenic chemicals were investigated in a water-based setting at normal room temperature. The reactions were carried out using a new type of catalyst called Fe3O4@SiO2@IDA-Cu, which is an organometallic nanocatalyst. This led to the creation of new versions of 6,6´-methylene bis-1,4-dihydropyridine-2,3- dicarboxylates with antioxidants and antibacterial activity.

Enhanced Catalytic Activity of Binuclear Oxidovanadium(IV) Bisbenzimidazole Linked Porphyrin Dimer for the Generation of Biologically Active 3,4-Dihydropyrimidinones and Their Corresponding Thiones.

Binuclear vanadyl(IV) porphyrin (V2BP), where two vanadium(IV) porphyrin macrocycles are linked through benzimidazole units at the β-positions, has been prepared and characterized with various techniques, such as UV-vis, Fourier transform-infrared, electron paramagnetic resonance, cyclic voltammetry, density functional transform calculations, and mass spectrometry. V2BP exhibits a red shift (Δλmax = 10 nm) in the Soret band as compared with unsubstituted parent vanadyl(IV) meso-tetraphenylporphyrin (VP). The synthesized binuclear vanadyl(IV) porphyrin (V2BP) has further been studied as a catalyst to explore a single-pot multicomponent Biginelli reaction producing biologically active 3,4-dihydropyrimidin-2-(1H)-one (DHPM)-based biomolecules and the corresponding thiones under solvent-free conditions and its catalytic activity has been compared with vanadyl(IV) meso-tetraphenylporphyrin (VP). Several reaction conditions, such as the amount of catalyst, time, solvent, and temperature, have been optimized to obtain the maximum yield of DHPMs or thiones. The synthesized β-functionalized V2BP porphyrin dimer manifests much higher conversion (84-95% yield) of DHPMs or the corresponding thiones under the optimized reaction conditions with high TON (4454-5037) and TOF (1113-1259 h-1) values for the one-pot multicomponent Biginelli reaction as compared to the literature. The catalyst exhibited excellent recyclability up to 10 cycles.

Green and Convenient Synthesis of Pharmaceutically Active Mono and Bis-dihydroquinazolines via a One-pot Multicomponent Reaction Under Sulfamic Acid Catalysis

Introduction: Multicomponent reactions (MCRs) and green chemistry are essential criteria for the development of efficient chemical syntheses for valuable organic compounds. Method: The design, synthesis, and development of sustainable procedures for the production of novel biological and pharmaceutical molecules have gained high importance. Herein, an environmentally benign synthesis of mono- and bis-2,3-dihydroquinazolin-4(1H)-ones as pharmaceutically active compounds was carried out in good to high yields of 80-99% within 45-120 minutes. Result: The desired products were synthesized via three-component and pseudo five-component condensations of isatoic anhydride, a primary amine (aniline or ammonium acetate), and an aldehyde/dialdehyde using sulfamic acid (20%) as a solid acidic catalyst under the solvent-free condition at 100°C. Conclusion: The easy work-up procedure, metal-free and environmentally benign catalyst, green reaction conditions for performing MCRs, and high yields of pure products are some advantages of the presented protocol.

Ultrasound Assisted and SO4-2/SnO2-Catalyzed One-Pot Multicomponent Reaction for the Synthesis of 1,2,3,4,6-Pentasubstituted Piperidines

Ultrasound Assisted and SO4-2/SnO2-Catalyzed One-Pot Multicomponent Reaction for the Synthesis of 1,2,3,4,6-Pentasubstituted Piperidines

Synthesis of Polysubstituted Pyridines via Nitrogen-doped Graphene Catalyzed One-Pot Multicomponent Reaction under Solvent-Free Conditions

Abstract: Polysubstituted pyridine derivatives were produced with high to excellent yields in the presence of nitrogen-doped graphene (NDG) as a dual acid-based catalyst. NDG efficiently catalyzes the multicomponent reaction between arylaldehydes, diethyl-acetylene dicarboxylates, malononitrile, and ammonium acetate under solvent-free conditions at 80°C to afford the polysubstituted pyridines in short reaction times. The structures of the synthesized pyridines were established by Ft-IR, 1H, and 13C NMR spectroscopic analysis. The advantages of this method include the in-situ oxidation of prepared 1,4-dihydropyridines, one-pot procedure, solventless system, operational simplicity, and no column chromatography. Additionally, neither toxic solvents nor catalysts are needed, and the procedure can be very reliable among the reported methodologies. The yields and reaction times in the presence of four times recycled catalyst are in comparable to the fresh catalyst.

Synthesis and biological evaluation of new 2-Amino-7-hydroxy-8-methyl-4-aryl-4H-chromene-3-carbonitrile derivatives

A series of new 2-amino-7-hydroxy-8-methyl-4-aryl-4H-chromene-3-carbonitrile derivatives (4a-4g) have been synthesized by a one-pot multicomponent reaction of 2-methylresorcinol (1) and malononitrile (2) with various aldehydes (3). All the synthesised compounds (4a-4g) have been characterised using FT-IR, 1H NMR, 13C NMR, HR-MS and evaluated for swarming behaviour, biofilm formation, biofilm disruption and urease activity against P. mirabilis (MTCC-425). Among all the synthesized compounds, compounds 4a, 4b and 4g showed slightly inhibited swarming behaviour and compounds 4f and 4g inhibited biofilm formation with increasing concentration. SEM (Scanning Electron Microscope) imaging shows that compound 4e effectively disrupts the preformed biofilm. Also, compounds 4d and 4e showed 40% reduction in urease activity. The SAR studies of synthesized compounds are elaborated in detail to provide key structural features. Furthermore, molecular docking studies against urease could provide a mechanistic basis for the inhibition. The per-residue interaction analysis suggested the involvement of non-bonded and bonded interactions with the active site of urease. Hence, the aim of the below study was to synthesize new chromene derivatives and study their biological activities.

Organoselenium-Catalyzed C2,3-Diarylation of N-H Indoles.

An organoselenium-catalyzed C2,3-diarylation of unprotected N-H indoles with electron-rich aromatics has been developed. This one-pot multicomponent tandem cross-dehydrogenation coupling reaction allows for the incorporation of two different aromatic groups to indoles. More importantly, this approach offers significant advantages, including a high atom and step economy, eliminating the need for prepreparation of the reaction substrates, streamlining the synthetic process and enhancing its practicality. Overall, this organoselenium-catalyzed C2,3-diarylation reaction presents an efficient and versatile strategy for the functionalization of indole derivatives.

One-pot multicomponent reaction: An efficient synthesis of 4-(HET)Aryl-substituted pyrazolo-quinolinones.

Pyrazolo-quinolinones (PQs) are a versatile class of Organic chemistry and it was found that they have very advanced functionally promising as selective compounds due to their scaffold and demonstrated low toxicity and considerable clinical promise. Moreover, these compounds have an important role in different applications such as analytical reagents, technical, pharmaceutical development, and biological markers. So, we aimed to synthesize and characterize new 4-(Het)aryl-substituted Pyrazole-quinolinones. Synthesis of One-Pot Multicomponent Reaction was carried out with the reaction of 5-amino-3-methyl-1H-pyrazole 1a, and 5-amino-3-phenyl-1H-pyrazole 1b and dimedone 2 with some (het)aryl aldehydes 3 using ethanol. Characterizations such as the linear structures and the regiospecificity of the reactions were determined by using NMR, GC-MS, IR, and UV measurements. This research will be very useful for all methods and procedures using multi-one-point reactions which are very popular in the synthesis of heterocyclic systems for pyrazole- quinoline skeleton synthesis.

TCS/ZnCl2 as a controlled reagent for the Michael addition and heterocyclic cyclization based on the phenyl pyrazolone scaffold with docking validation as a Covid-19 protease inhibitor

TCS/ZnCl2 is presented as a new catalyst for achieving the Michael addition adduct 5a-g by the reaction of phenyl pyrazolone 4 as the Michael donor and arylidene derivatives 3a-g as the Michael acceptor. The one-pot multi-component reaction of the same fragments' scaffolds as aldehydes 1a-g, malononitrile (2), and phenyl pyrazolone 4 with the same catalyst gives pyrano[2,3-c]pyrazole derivatives 6a-g as final products. The prepared compounds undergo docking validation as COVID-19 protease inhibitors and are compared with hydroxychloroquine as a reference drug. KEY WORDS: Pyranopyrazole, multi-component reactions, TCS/ZnCl2 catalyst, COVID-19, the energy score, hydroxychloroquine Bull. Chem. Soc. Ethiop. 2024, 38(4), 1119-1127. DOI: https://dx.doi.org/10.4314/bcse.v38i4.24

A efficient, regioselective and solvent free synthesis of 5,9-dihydropyrimido[4,5-e][1,2,4]triazolo[1,5-a]pyrimidine-6,8(4H,7H)-diones derivatives in presence nanocatalyst sulfuric acid grafted with silica-3-aminotriazol

In this research, SO3H-functionalized Silica grafted 3-amino triazol has been prepared and identified through FT-IR, XRD, EDX, Fe-SEM, and TGA spectra. 3-chloropropyltriethoxysilane was first reacted with silica nanoparticles and then treated with 3-amino-1H-1,2,4-triazoles and grafted finally with chlorosulfonic acid to prepare SiO2@(CH2)3-AT/SO3H (SNPS-AT/SO3H). Afterward, the catalytic efficiency has been investigated as a homogeneous and recyclable catalyst for the solvent-free synthesis of 5,9-dihydropyrimido[4,5-e][1,2,4]triazolo[1,5-a]pyrimidine-6,8(4H,7H)-diones by the one-pot multi-component reaction of aromatic aldehydes with 3-amino-1H-1,2,4-triazoles and 1,3-dimethyl barbituric acid under thermal (100 °C) conditions.

CuPd bimetallic nanoparticles supported magnetic ionic liquid-derived N-doped carbon as a highly efficient heterogeneous catalyst for the one-pot oxidative multicomponent reactions

BackgroundMulticomponent reactions often rely on aldehydes as the reactants, limiting their widespread use. To enhance the versatility and scope of these reactions, aldehydes can be replaced with alcohols. MethodsIn this study, nitrogen-doped magnetic carbon nanostructures modified with imidazolium-based ionic liquid (Fe3O4@NC-IL) were prepared. These nanostructures were synthesized by a one-pot hydrothermal carbonization method using ferric chloride in the presence of glucose, urea, epichlorohydrin and 1-methylimidazole as carbon source, nitrogen source, linker and ionic liquid, respectively. Then, CuPd bimetallic nanoparticles were immobilized on the synthesized nanostructures by a wet chemical reduction process. Significant findingsThe catalytic activity of the nanostructures was evaluated in the oxidation of alcohol under base-free conditions. The results indicate that the CuPd bimetallic catalyst exhibited better catalytic performance than both Cu and Pd monometallic catalysts, suggesting a synergistic effect between copper and palladium. Also, a non-ionic liquid-based catalyst was synthesized and used in the model reaction to study the effect of imidazolium ionic liquid species on the catalytic activity. The results showed that these species enhanced the catalytic activity. Finally, the catalytic activity of the synthesized structure was evaluated through a one-pot tandem oxidative synthesis of dihydropyrimidinones (Biginelli reaction) and dihydropyridines (Hantzsch reaction).

Polymer Supported Nitrogen-Bridged Symmetrical Binuclear Dioxidomolybdenum(VI) Complexes and Their Homogeneous Analogues as Potential Catalysts for Efficient Synthesis of 2-Amino-3-Cyano-4H-Chromenes/Pyrans.

Reaction of 2-chloromethyl-1H-benzimidazole with known intermediates (i-iii), prepared from diaminoguanidine hydrochloride with salicylaldehyde, 5-bromosalicylaldehyde or 3,5-di-tert-butylsalicylaldehyde, in the presence of triethylamine (NEt3) led to the formation of benzimidazole appended new ligands, H4L1-H4L3 (I-III). The homogeneous nitrogen-bridged symmetrical binuclear complexes, [(MoVIO2)2(L1)(H2O)2] (1), [(MoVIO2)2(L2)(H2O)2] (2) and [(MoVIO2)2(L3)(MeOH)2] (3) have been isolated by reacting these ligands with [MoVIO2(acac)2] in a 1 : 2 molar ratio in refluxing methanol. Using 1 : 1 (ligand to Mo precursor) molar ratio under above reaction conditions resulted in the corresponding mononuclear complexes, [MoVIO2(H2L1)(MeOH)] (4), [MoVIO2(H2L2)(H2O)] (5) and [MoVIO2(H2L3)(MeOH)] (6). The binuclear heterogeneous compounds [(MoVIO2)2(L1)(DMF)2]@PS (PS-1), [(MoVIO2)2(L2)(DMF)2]@PS (PS-2) and [(MoVIO2)2(L3)(DMF)2]@PS (PS-3) have been obtained by immobilization of 1-3 onto chloromethylated polystyrene (PS) beads. All synthesized ligands, homogeneous as well as supported compounds have been characterized by elemental analyses and various spectroscopic methods. Single crystal X-ray diffraction study of complexes 1 and 3 confirms their nitrogen-bridged symmetrical binuclear structures while 4 is mononuclear. Heterogeneous compounds (PS-1-PS-3) have further been studied by microwave plasma atomic emission spectroscopy, X-ray photoelectron spectroscopy, and field emission scanning electron microscopy along with energy dispersive spectroscopy. These compounds (homogeneous and heterogeneous) were explored for catalytic applications to one-pot multicomponent reactions (MCRs) for efficient synthesis of biologically active 2-amino-3-cyano-4H-chromenes/pyrans (21 examples). Optimising various reaction parameters helped in achieving as high as 97 % yields of products. Though, only half equivalent of the binuclear complexes (1-3) was required compared to mononuclear analogues (4-6) to achieve comparable yields, heterogeneous catalysts have an added advantage due to their stability and recyclability. Suitable reaction mechanism has also been proposed based on isolated intermediates.

Novel pyridine bearing pentose moiety-based anticancer agents: design, synthesis, radioiodination and bioassessments

Pyridine compounds are one of the most important heterocyclic derivatives showing wide ranges in biological and pharmacological activities. Green chemistry eliminates or reduces the generation of hazardous compounds. It prevents pollution at a molecular level. The microwave technique used in heterocyclic compound synthesis is also an important branch of green chemistry techniques. In this study, we report designing and synthesizing a new pyridine-bearing pentose moiety via a one-pot multicomponent reaction using D-glucose and also investigate its behavior and reactivity toward some simple and heterocyclic amino derivatives. The chemical structures of the synthesized compounds were characterized and tested for their cytotoxic activities. Some of the test compounds exhibited slight to high cytotoxic activities against Caco2 (colon cancer) cells, HepG2 (hepatocellular carcinoma) cells and MCF-7 (human breast cancer) cells by MTT assay. The results showed clearly that compound 4 and compound 8 displayed strongest to moderate cytotoxic activity against the HepG2, Caco2 and MCF-7 respectively and compound 1 showed good activity against MCF-7 in comparison to the standard anticancer drug doxorubicin. These data were by cytopathological examination. An in-vivo radioactive tracing study of compound 4 proved its targeting ability to sarcoma cells in a tumor-bearing mice model. Our findings suggest that the synthesized compounds may be promising candidates as novel anticancer agents.

A Review on the Recent Multicomponent Synthesis of 4H-Pyran Derivatives

Abstract: 4H-Pyran is a well-known moiety, which appears in various natural and synthetic products. These compounds include various biological activities like anti-hepatotoxic, antitumor, anti-inflammatory, antioxidant, anti-spasmolytic, diuretic, estrogenic, anticoagulant, antifungal, antiviral, anti-helminthic, antimicrobial, hypothermal, anti-tubercular, anti-HIV, herbicidal, anticonvulsant and analgesic activity. This review has summarized an overview of general strategies that allow the design of 4H-pyran derivatives via catalyzed one-pot multicomponent reactions.

Reaction Optimization of Strontium Perchlorate Catalyzed Novel Protocol for Stereoselective Synthesis of Dihydropyrimidinones.

Hydrated strontium perchlorate [Sr(ClO4)2.3H2O] acts as a very strong oxidizing and dehydrating agent. Until now, it could not be reported as a catalyst in dehydration mechanism-based organic synthetic reactions. Therefore, it is important to find whether it could be an effective catalyst for one-pot multicomponent reactions (MCRs). The main objective of the present work is the development of a novel process for the synthesis of 1,4-dihydropyrimidinones through the one-pot multicomponent strategy using hydrated Sr(ClO4)2 as a catalyst. Furthermore, it includes process optimization, stereoselectivity, and spectroscopic characterization of the synthesized compounds. Conventional and microwave-supported synthesis of 1,4-dihydropyrimidinones using 20 mol % of hydrated Sr(ClO4)2 catalyst via the one-pot solvent-free reaction was discovered as a new catalytic MCR methodology. The box-Behnken design approach and advanced analytical techniques were used for process optimization and reaction analysis. The results confirmed that hydrated Sr(ClO4)2; works as an efficient catalyst for one-pot multicomponent organic synthesis under both conventional and microwave heating. It is an effective catalyst for laboratory synthesis of 1,4-dihydropyrimidinones stereoselectively with moderate to excellent yield without any undesirable effect. Microwave heating provided the desired product within 1-4 minutes. Moreover, this method provides easy isolation of the pure products simply by recrystallization, and without the use of a chromatographic purification method. The simplicity and neutrality of reaction conditions, easy post-reaction workup, higher satisfactory to excellent yield, effectiveness, the diversity of substrates, etc. render the hydrated Sr(ClO4)2 catalyst-based protocol for the stereoselective synthesis of 1,4-dihydropyrimidinones as a highly efficient method. Furthermore, it has been found to be safe un-der laboratory reaction conditions and no undesirable issues have been faced during the process.

Novel terpyridines as Staphylococcusaureus gyrase inhibitors: efficientsynthesis and antibacterialassessment viasolvent-drop grinding.

Aim: This study was designed to synthesize a novel series of terpyridines with potential antibacterial properties, targeting multidrug resistance. Materials & methods: Terpyridines (4a-h and 6a-c) were synthesized via a one-pot multicomponent reaction using 2,6-diacetylpyridines, benzaldehyde derivativesand malononitrile or ethyl 2-cyanoacetate. The reactions, conducted under grinding conditions with glacial acetic acid, produced high-yield compounds, confirmed by spectroscopic data. Results: The synthesized terpyridines exhibited potent antibacterial activity. Notably, compounds 4d and 4h demonstrated significant inhibition zones against Staphylococcusaureus and Bacillussubtilis, outperformingciprofloxacin. Conclusion: Molecular docking studies highlighted compounds 4d, 4hand 6c as having strong binding affinity to DNA gyrase B, correlating with their robust antibacterial activity, suggesting their potential as effective agents against multidrug-resistant bacterial strains.