Search

This computational study explores the copper (I) chloride catalyzed synthesis of (E)‐1‐(2,2‐dichloro‐1‐phenylvinyl)‐2‐phenyldiazene (2Cl‐VD) from readily available hydrazone derivative and carbon tetrachloride (CCl4). 2Cl‐VD has been extensively utilized to synthesize variety of heterocyclic organic compounds in mild conditions. The present computational investigations primarily focus on understanding the role of copper (I) and N1,N1,N2,N2‐tetramethylethane‐1,2‐diamine (TMEDA) in this reaction, TMEDA often being considered a proton scavenger by experimentalists. Considering TMEDA as a ligand significantly alters the energy barrier. In fact, it is only 8.3 kcal/mol higher compared to the ligand‐free (LF) route for the removal of a chlorine atom to form the radical ·CCl3 but the following steps are almost barrierless. This intermediate then participates in attacking the electrophilic carbon in the hydrazone. Crucially, the study reveals that the overall potential energy surface is thermodynamically favorable, and the theoretical turnover frequency (TOF) value is higher in the case of Cu(I)‐TMEDA complex catalyzed pathway. [ABSTRACT FROM AUTHOR]

Investigation into the interactions between drugs and biomolecules can offer a precise understanding of their biological behaviours in vitro and in vivo, providing crucial insights for designing new drugs. Herein, we report the design, synthesis, and characterization of a bicyclic hydrazone derivative, along with its potential as an inhibitor of human neutrophil elastase (HNE), a critical enzyme in the treatment of acute and chronic lung injuries. We present an improved protocol for the synthesis of the compound using N‐amino‐bicyclo[2.2.1]hept‐5‐ene‐2,endo‐3‐endo‐dicarboximide and 4‐(trifluoromethyl)benzaldehyde through a facile, one‐pot, catalyst‐free synthesis in dry ethanol at reflux temperature. Within 12 hours, bicyclic‐hydrazone derivative was obtained with yields of up to 75 % and was characterized using various spectroscopic techniques and computational analyses based on the DFT approach. In silico ADME/T profile of the compound was evaluated and molecular docking simulation was utilized to predict its potential as a HNE inhibitor. The binding energy values of the THI ligand to the chosen PDB ID: 5ABW, 3Q77, and 2RG3 target proteins were determined as −8.41, −7.20, and −7.27 kcal/mol, respectively. In silico analysis findings indicate that the THI compound has promising drug‐likeness properties and has the potential to be evaluated in the development of new HNE inhibitors. [ABSTRACT FROM AUTHOR]

The data on the synthesis of N-aminomorpholine hydrazones are presented. It is shown that the interaction of N-aminomorpholine with functionally substituted benzaldehydes and 4-pyridinaldehyde in isopropyl alcohol leads to the formation of corresponding hydrazones. The structure of the synthesized compounds was studied by 1H and 13C NMR spectroscopy methods, including the COSY (1H-1H), HMQC (1H-13C) and HMBC (1H-13C) methodologies. The values of chemical shifts, multiplicity, and integral intensity of 1H and 13C signals in one-dimensional NMR spectra were determined. The COSY (1H-1H), HMQC (1H-13C), and HMBC (1H-13C) results revealed homo- and heteronuclear interactions, confirming the structure of the studied compounds. The antiviral, cytotoxic, and antimicrobial activity of some synthesized hydrazones were investigated. It is shown that 2-((morpholinoimino)methyl)benzoic acid has a pronounced viral inhibitory property, comparable in its activity to commercial drugs Tamiflu and Remantadine. A docking study was performed using the influenza virus protein models (1930 Swine H1 Hemagglutinin and Neuraminidase of 1918 H1N1 strain). The potential binding sites that are complementary with 2-((morpholinoimino)methyl)benzoic acid were found. [ABSTRACT FROM AUTHOR]

Context: Hydrazones have been studied for a myriad of chemical and physiochemical properties, such as sensors, chelators and numerous biological activities. Experimental data indicates that hydrazones are unstable under cathodic potentials irrespective of the solvent. The single electron reduction of hydrazones to produce radical anions result in unstable species that cleaves at the N–N bond in a heterolytic manner. The literature has proposed a mechanism favouring the radical on the imine moiety, however in this study DFT calculations suggest the radical on the amine product is more likely upon bond cleavage. This has implications on electrochemical mechanisms, and the active molecule in biological studies viz the method of delivery to target areas. Methods: Density functional theory calculations were carried out using the GAMESS software package. The structures were optimized in the gas phase (B3LYP/6-31G(d,p)) as indicated by the absence of imaginary frequencies in the Hessian, and in CH3CN (B3LYP/6-31G(d,p)/SMD) with the Pople polarization functions. As a comparison, selected pathways were fully optimized using PBE0/6-31G(d,p) and PBE0/6-31G(d,p)/SMD for gas phase and CH3CN, respectively with the Pople polarization functions. The values were not significantly different (< 5% difference). As such only the B3LYP is evaluation is discussed. [ABSTRACT FROM AUTHOR]

Hydrazone‐linked covalent organic frameworks (COFs) with structural flexibility, heteroatomic sites, post‐modification ability and high hydrolytic stability have attracted great attention from scientific community. Hydrazone‐linked COFs, as a subclass of Schiff‐base COFs, was firstly reported in 2011 by Yaghi's group and later witnessed prosperous development in various aspects. Their adjustable structures, precise pore channels and plentiful heteroatomic sites of hydrazone‐linked structures possess much potential in diverse applications, for example, adsorption/separation, chemical sensing, catalysis and energy storage, etc. Up to date, the systematic reviews about the reported hydrazone‐linked COFs are still rare. Therefore, in this review, we will summarize their preparation methods, characteristics and related applications, and discuss the opportunity or challenge of hydrazone‐linked COFs. We hope this review could provide new insights about hydrazone‐linked COFs for exploring more appealing functions or applications. [ABSTRACT FROM AUTHOR]

A bis-ferrocene macrocycle was synthesized by reversible acylhydrazone formation under thermodynamic control, starting from a ferrocene functionalized with hydrazide and protected aldehyde moieties. A hydrogen sulfate anion acts as a template to direct the synthesis specifically toward the macrocyclic dimer, due to a weak but selective binding interaction. This work highlights the utility of dynamic combinatorial chemistry as an approach to macrocycle synthesis. [ABSTRACT FROM AUTHOR]

This article discusses the synthesis of acyl hydrazides and hydrazones from activated amides, which are nitrogen-containing compounds found in pharmaceutical and agricultural compounds. The traditional method for synthesizing acyl hydrazides has limitations, but recent advancements in carbon-nitrogen bond activation reactions have opened up new possibilities. The article provides a comprehensive account of the results and methodologies for synthesizing these compounds, including the synthesis and characterization of various benzohydrazide compounds. The document also includes specific details for the synthesis and characterization of one compound, (E)-N'-(4-methylbenzylidene)benzohydrazide. The document provides experimental results, including yields, melting points, and spectroscopic data, and acknowledges the Korea Basic Science Institute for providing additional data. [Extracted from the article]

A method was developed for synthesizing previously unknown hydrazones containing two pharmacophoric fragments in their structure based on the reaction of phenyl/acylhydrazines with 1-(1-tosylpyrrolidin-2-yl)propan-2-one. Structure of the resulting hydrazones was established using 1H, 13C NMR, IR spectroscopy, and mass spectrometry (ESI-TOF) data. Based on 1D/2D correlation NMR experiments, it was found that the resulting hydrazones exist only as E-isomer. [ABSTRACT FROM AUTHOR]

We systematically investigated the first-order molecular hyperpolarizability, a second-order nonlinear optical phenomenon of 185 organic compounds comprising both benzophenone and benzophenone hydrazone derivatives. We considered compounds with different combinations of electron donor groups -H, -F, -CH3, -Cl, -Br, OCH3, -NH2, -NHCH3, -NHC2H5, -N(CH3)2, and electron acceptor group -NO2 attached to the para positions R1 or R2 of the aromatic rings. The reported first-order molecular hyperpolarizability values were obtained by quantum-chemical calculations using semiempirical and density functional theory approaches in the gas phase. Our results reveal that BP-25 (R1 = NO2, R2 = N(CH3)2) and BPH-39 (R1 = N(CH3)2, R2 = NO2) exhibited the highest dynamic first-order molecular hyperpolarizability value of about . These findings underline the potential of specific BP and BPH derivatives as candidates for photonic applications, particularly for developing second harmonic generation crystals. [ABSTRACT FROM AUTHOR]

In the presence of ethanol solvent and glacial acetic acids, triazole reacted with different aromatic aldehydes such as 4-methoxybenzaldehyde, 4-hydroxybenzaldehyde, and benzaldehyde to form the imines group known as Schiff bases. Triazole Schiff bases are triazole hydrazone and their derivatives, VA, VB, and VC. The structures of these synthetic triazole hydrazone derivatives were characterized by means of FT-IR and mass spectrometry. The purities and quality of the compounds were evaluated using TLC. It was established, that the active ingredient in the synthesised triazole hydrazone was more effective against the infections than cefuroxime. [ABSTRACT FROM AUTHOR]

Using a diazonium combination of aniline and 1,3‐diphenylpropane‐1,3‐dione, the Japp‐Klingemann reaction yielded the 1,3‐diphenyl‐2‐(2‐phenylhydrazono)propane‐1,3‐dione ligand (HL). The copper (II) complex has been made using copper (II) acetate salt. The geometry of HL and its Cu (II) chelate were described through CHN analyses, FTIR, UV–Visible, XRD, TGA, and magnetic susceptibility tests. According to the spectral data, the ligand exhibits monobasic bidentate behavior by connecting through the N atom of hydrazone moiety (=N − NH−) by deprotonating beside the oxygen atom of the carbonyl (C=O) group forming octahedral geometry. Density functional theory (DFT) calculations were done by molecular studio software to examine the optimal geometry of HL and its complexity. MCF‐7 and HepG‐2 cell lines demonstrated anticancer action in response to the HL and its copper (II) complex. Additionally, inhibition zone diameter was used to assess the in vitro antibacterial action of HL and particular complex toward Gram +ve bacteria Staphylococcus aureus and Gram‐ve bacteria Escherichia coli (E. coli). Both viscosity and absorption spectra of Calf‐thymus DNA binding experimentations were used to examine the compounds. [ABSTRACT FROM AUTHOR]

Cd (II), Mn (II), Zn (II), Cr (III), and Fe (III) complexes of a carbohydrazone ligand H4EBC, prepared by the reaction of ethyl acetate and carbohydrazide, have been prepared and fully characterized. The ligand H4EBC acted as a bidentate carbohydrazone with Cd (II) and coordinated through the nitrogen of both (‐NH) and (C=N)azomethine groups, while with Mn (II) and Zn (II), it acted as a neutral NN bidentate ligand. In complexes with Fe (III) and Cr (III), H4EBC acts a bi‐negative tetra‐dentate, coordinating through the oxygen atoms of both enolized (C=O)ester groups and the nitrogen of both (C=N)azomethine groups. To illustrate the proposed geometries and chemical reactivity of the compounds, we employed DFT calculations. Additionally, thermal studies provided insights into the stability of the isolated compounds. Interestingly, the prepared complexes demonstrated emission broad bands at various wavelengths, indicating ligand to metal charge transfer. Based on the inhibition of DNA destruction, the complexes can be ranked in the following order: [Cd(H4EBC)Cl2].2H2O] (1) > H4EBC > [Mn(H4EBC)Cl2)].(H2O)2] (2) > [Zn(H4EBC)Cl2].2H2O] (3) > [Fe(H2EBC)Cl(H2O)].H2O (5) > [Cr(H2EBC)Cl (H2O)].H2O (4). Regarding erythrocyte hemolysis, the order of effectiveness can be arranged as follows: (2) > (1) > H4EBC > (5) > (3) > (4). We further investigated the compounds for their potential in antitumor activity against two cell lines and antimicrobial behavior. [ABSTRACT FROM AUTHOR]

Hydrazones display an interesting profile of biological activities, which includes mainly antimicrobial and antiproliferative properties. Hydrazones also play an important role in the synthesis of heterocyclic rings and in coordination chemistry. Currently, the synthesis of complexes of hydrazones with transition metals is quite frequently reported in the scientific literature. The interest in this topic is largely due to diverse biological activities of the metal complexes of hydrazones that in some cases are much more effective than hydrazones themselves. This review focuses on the complexes of hydrazones with transition metals which display antibacterial, antitubercular, antifungal and anticancer activities. In the following subchapters devoted to a given activity, an attempt has been made to present the most active complexes of hydrazones, their trends in their activity and application in medicinal chemistry. The paper presents the literature data from 2009 to 2023. This review constitutes a useful guide for the researchers who intend to synthesize and investigate complexes of hydrazones in terms of their antimicrobial and anticancer activities. [ABSTRACT FROM AUTHOR]

A highly sensitive micelle-induced sensory has been developed for detection of long-chain aldehydes as potential biomarkers of respiratory cancers. The micelle-like sensor was fabricated through the partial self-assembly of CTAB and S2 surfactants, containing a fluorescent hydrazine-functionalized dye (Naph-NH2). In principle, long-chain aldehydes with amphiphilic character act as the induced-fit surfactants to form well-entrapped micellar particles, as well as react with Naph-NH2 to form hydrazone derivatives resulting in fluorescent enhancement. The limit of detection (LOD) of micellar Naph-NH2/CTAB/S2 platform was calculated to be ∼ 64.09–80.98 µM for detection of long-chain aldehydes, which showed fluorescent imaging in lung cancer cells (A549). This micellar sensory probe demonstrated practical applicability for long-chain aldehyde sensing in human blood samples with an accepted percent recovery of ~ 94.02–102.4%. Beyond Naph-NH2/CTAB/S2 sensor, the milcellar hybrid sensor was successfully developed by incorporating a micelle-like platform with supramolecular gel regarding to carboxylate-based gelators (Gel1), which showed a tenfold improvement in sensitivity. Expectedly, the determination of long-chain aldehydes through these sensing platforms holds significant promise for point-of-care cancer diagnosis and therapy. [ABSTRACT FROM AUTHOR]

For the first time, the interaction of aroyl containing pyrano[2,3-d]isoxazolone derivatives with various hydrazines was studied. It was shown that the considered process includes formation of corresponding hydrazones followed by Boulton–Katritzky rearrangement. As a result, the general method for the synthesis of substituted 1,2,3-triazoles bearing an allomaltol fragment was elaborated. The suggested approach can be applied to various aromatic and heterocyclic hydrazines. At the same time for unsubstituted hydrazine the Boulton–Katritzky recyclization is not implemented. In this case the opening of the pyranone ring was observed leading to pyrazolylisoxazole derivatives. Both types of aforementioned structures were proved by X-ray analysis.

The chemically triggered reversible switching of pH‐responsive hydrazones involves rotary motion‐induced configurational changes, serving as a prototype for constructing an array of molecular machines. Typically, the configurational isomerization of such switches into two distinct forms (E/Z) occurs through the alteration of the pH the medium, achieved by successive additions of acid and base stimuli. However, this process results in intermittent operation due to the concomitant accumulation of salt after each cycle, limiting switching performance to only a few cycles (5–6). In this context, we introduce a novel strategy for the autonomous E/Z isomerization of hydrazones in acetonitrile using pulses of trichloroacetic acid as a chemical fuel. The use of this transient acid enabled reversible switching of hydrazones even after 50 cycles without causing significant fatigue. To test the broad viability of the fuel, a series of ortho/para‐substituted hydrazones were synthesized and their switching performance was investigated. The analysis of kinetic data showed a strong dependency of switching operations including the lifetime of transient state, on the electronic properties of substituents. Finally, a distinct color change from yellow to orange due to reversible switching of the para‐methoxy substituted hydrazone was employed for the creation of rewritable messages on commercially available paper. [ABSTRACT FROM AUTHOR]

Hydrazones as organometallic equivalents have emerged as a general and sustainable strategy to utilize naturally abundant aldehydes and ketones as feedstocks while only releasing water and nitrogen gas as byproducts. Yet the addition of these carbanion equivalents to carbonyl compounds has been limited to the use of precious metals as catalysts and hazardous solvents under an inert atmosphere. Herein, we report the development of a manganese-based catalyst system for the addition of aldehydes to carbonyl compounds producing secondary and tertiary alcohols with yields of up to 91%. Furthermore, this method has proven robust and reproducible under aqueous and aerobic conditions to employ an earth-abundant metal catalyst, hence advancing hydrazone umpolung chemistry to be more sustainable and operationally simple. [ABSTRACT FROM AUTHOR]

The method for the preparation of 3,6-disubstituted 1,2,4-triazines based on condensation reaction between easily available α-imino esters and isonitrosoacetophenone hydrazones was reported. The significant differences in reaction conditions, ratio of products, and yields between the developed method and the earlier reported approach were demonstrated. The corresponding 2,5-disubstituted pyridines were synthesized from the prepared 1,2,4-triazines, and their photophysical properties were studied. Studies of the photo-physical properties revealed low and moderate luminescence quantum yields, and negligible solvatochromic behavior in case of 4-methoxyphenylpyridine derivative due to the role of donating methoxy group, however, with a low linearity of a Lippert–Mataga plot. Nevertheless, 2,5-disubstituted pyridines are of interest due to simple protocols of synthesis, moderate photophysical properties, and potential applicability in different scientific and industrial areas. [ABSTRACT FROM AUTHOR]

Objective: A new series of pyrazole-3-carbaldehyde derivatives from new hydrazones by using the Vilsmeier–Haack reaction were synthesized. Pyrazoles have the characteristic qualities of the aromatic system, which are generally quite evident in their structures having insecticide, herbicide, and healthful significance as anti-inflammatory properties and antipyretic medication actions. Pyrazole compounds have a wide spectrum of bioactivity as reported in the literature, which encourages synthesis and testing of the antimicrobial activity for synthesis compounds. Methods: P-acetamido-phenol, and 2-mercaptobenzoimidazole, which used as a starting materials for synthesis pyrazole-3-carbaldehyde derivatives. The biological activity of some prepared compounds was also tested against two G-positive bacteria and two G-negative bacteria, in addition to C. albinos fungi. A molecular modeling study of some prepared compounds showed good binding strength with the target protein. Results and Discussion: Compound N-(4-((5-(4′-(4-formyl-1-phenyl-1H-pyrazole-3-carbonyl)-[1,1′-biphenyl]4-yl)-1,3,4-oxadiazol-2-yl)methoxy) phenyl)acetamide passes a good activity against Staphylococcus aurous; the compound 3-(4′-(5-(((1H-benzo[d]imidazol-2-yl)thio)methyl)-1,3,4-oxadiazol-2-yl)-[1,1′-biphenyl]-4-carbonyl)1-phenyl-1H-pyrazole-4-carbaldehyde passes good active with C. albinos. Molecular modeling was studied for the compounds prepared with human corona virus NL63, compound N-(4-((5-(4′-(4-formyl-1-phenyl-1H-pyrazole-3carbonyl)-[1,1′-biphenyl]-4-yl)-1,3,4-oxadiazol-2-yl)methoxy)phenyl)acetamide has best docking score –181.9 kcal/mol, while compound 3-(4′-(5-(((1H-benzo[d]imidazol-2-yl)thio)methyl)-1,3,4-oxadiazol-2-yl)[1,1′-biphenyl]-4-carbonyl)-1-(4-nitroph enyl)-1H-pyrazole-4-carbaldehyde has best hydrogen-bonding with –10 kcal/mol. In general, the binding by hydrogen bonding and steric interference was high, which leads to the conclusion that the prepared compounds have an effect on the Corona virus. Conclusions: The prepared compounds have biological activity and have good binding force with the Corona virus protein NL63, thus disrupting its work, and ccording to the toxicity assessment, the synthesized compounds belong to the third class (III). [ABSTRACT FROM AUTHOR]

Hydrazones are a large group of compounds with antibacterial, antituberculosis, antifungal, anticonvulsant, antiviral, antiprotozoal, anticancer and anti-inflammatory properties. Ten newly synthesized hydrazones were tested for their antimicrobial and antituberculosis activities. Screening tests were performed using the disk diffusion method. Then, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration were determined for the most promising compounds. Synergy of the action of the tested substances with reference drugs was also tested. Drugs standardly used in the treatment of tuberculosis: rifampicin and isoniazid were used as reference substances. Based on the obtained results, fractional inhibitory concentration coefficients were calculated for individual combinations. The tested ones showed weak antimicrobial activity. They didn't show either synergism of action with rifampicin and isoniazid. Then, experimental and theoretical lipophilicity parameters were determined for the obtained derivatives. The research was carried out using reversed-phase high-performance liquid chromatography (RP-HPLC), in which the mobile phase is a mixture of methanol and water. To confirm the validity of the chromatographic technique used, both experimental and calculated lipophilicity parameters were correlated. The correlation matrix of these relationships was subjected to principal component analysis (PCA). [ABSTRACT FROM AUTHOR]

In this paper, we report the synthesis and the structure–activity relationship study of three hydrazone analogs; the Schiff base hydrazone SBH and 2, 4-dinitrophenylhydrazones H1 & H2 derived from (E)-chalcones, to identify the active fragment of each structure. This identification has been carried out following in vitro biological evaluation, which revealed that the analogs H1 and H2 showed significant antibacterial activity due to their (E)-chalcone fragments characterized by proton NMR data and demonstrated by the docked view with emphasis on the involvement of these moieties in the interaction with the DNA gyrase, and thus contributes to the pharmacophore modeling. At the same time, SBH exhibited the highest free radical DPPH scavenging power associated with hydrogen bonding and conjugated push−pull chromophores, which were elucidated by reported vibrational assignments and absorption spectra. The DFT optimizations gave rise to non-planar and distorted structures around the hydrazone group with comparable geometrical parameters. The chemical descriptors predict comparable biological activities, while the BDE necessary for the H-abstraction indicated the best antioxidant activity for the Schiff base hydrazone SBH compound. 2, 4-Dinitrophenylhydrazone analogs with (E)-chalcone and/or push-pull moieties were synthesized and characterized. The in-vitro and in-silico studies were carried out both to find the structure-activity relationship and to model the pharmacophore. [ABSTRACT FROM AUTHOR]

C-H borylation is a powerful strategy for the construction of C-B bonds due to the synthetic versatility of C-B bonds. Various transition metals affect the powerful functionalization of C-H bonds, of which Ir is the most common. Substrate-directed methods have enabled directed Ir-catalyzed C-H borylation at the ortho position. Amongst the powerful directing groups in Ir-catalyzed C-H borylation are N-containing carbocyclic systems. This review covers substrate-directed Ir-catalyzed ortho-C-H borylation of aromatic C(sp2)-H bonds in N-containing carbocyclic compounds, such as anilines, amides, benzyl amines, hydrazones, and triazines. [ABSTRACT FROM AUTHOR]

In the present study, new series of benzoxazolin-2-one linked to a variety of hydrazones and azoles were synthesized and assessed for their antibacterial properties against different bacterial microorganisms. All the synthesized target compounds were characterized by 1H NMR, 13C NMR and IR spectroscopy, and elemental analysis as well. The antibacterial activity of the synthesized compounds was evaluated according to the bacteriostatic and bactericidal activity against the tested pathogen strains by determining the minimum inhibition (MIC) and minimum bactericidal (MBC) concentrations and MBC/MIC ratios. The MIC was evaluated by the broth dilution and the MBC was evaluated by plating methods. The in vitro analysis suggested that some compounds, namely, amide, 5-chlorobenzimidazole, hydrazones with a 3-chloro substitution on the additional phenyl ring, and hydrazones with 2-furyl and 5-nitro-2-furyl substituents, demonstrated wide antibacterial activity against Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Salmonella Enteritidis. The most sensitive strains appeared to be Gram-negative E. coli and Gram-positive B. subtilis, while S. aureus showed some resistance. The most resistant pathogen was found to be S. enteritidis. The remaining compounds demonstrated moderate to low antibacterial potential. The research results have shown that benzoxazolinone-based derivatives are suitable for the development of a library of compounds and can be used in the future development of antibacterial drugs against various Gram-positive and Gram-negative pathogens, which is of great importance in therapy practice. [ABSTRACT FROM AUTHOR]

A method for synthesizing silyl arylsulfonyl hydrazones as silyldiazomethane precursors has been developed. Although silyldiazomethanes are an important class of diazo compounds, their use in intramolecular cyclization reactions has not been fully explored despite the rich chemistry of diazo compounds, particularly metal carbenoid chemistry. The fundamental challenge underlying the absence of such studies is the lack of a method for synthesizing silyldiazomethanes with functional groups that can react with metal carbenoids. The method reported here provides access to variety of silyl arylsulfonyl hydrazones with functional groups such as ethers, carbamates, and alkynes, which can serve as reaction sites for metal carbenoids. A one‐pot hydrazone formation using unstable formylsilane formed in situ is key to a successful synthesis. The use of 2,4,6‐trimethylbenzenesulfonohydrazide contributed toward achieving broad generality in hydrazone formation. The synthetic potential of this method was demonstrated through the generation of silyldiazomethane and its transformation to several silacycles. [ABSTRACT FROM AUTHOR]

A new mode of reactivity of N‐sulfonylhydrazones towards alkynes is described: ketone‐derived N‐tosylhydrazones (NTHs) bearing α‐H atoms behave as [NN] synthons in their reactions with alkoxy alkynyl Fischer carbene complexes (FCCs) and only the two N atoms are incorporated into the newly formed pyrazole ring. The scope of the reaction, leading to 5‐methoxy‐N‐alkenyl pyrazoles, proved to be wide regarding both partners; thus, a variety of aryl and primary, secondary, and tertiary alkyl substituents are tolerated within the FCC, while aryl alkyl NTHs, symmetric and asymmetric dialkyl NTHs and NTHs derived of cyclic ketones can be also employed. In addition, the reaction can be performed at large scale and applied for late‐stage diversification of natural products. A reasonable reaction mechanism is also proposed, which is supported by deuteration experiments and DFT calculations. [ABSTRACT FROM AUTHOR]

Our research has demonstrated that mechanochemical activation is more effective with solid reagents. We have showcased the practicality of Bertagnini's salts, also called aldehyde‐bisulfite adducts, which are crystalline, simplifying preparation and storage. These salts are stable substitutes for liquid aldehydes and ketones that have been employed in reductive amination, synthesizing aza‐heterocycles and hydrazones within mechanochemistry. The technique's effectiveness broadens the substrate scopes, simplifies purification, reduces reaction times, and yields the desired products ranging from 38–91%. Additionally, the thermal stability of the bisulfite adducts has been confirmed through TGA (Thermogravimetric analysis) analysis. [ABSTRACT FROM AUTHOR]

Since the development of the chemistry and applications of boron dipyrromethene dyes (BODIPYs), numerous other platforms based on boron complexes of N‐donor ligands have emerged as molecular optoelectronic materials. By tailoring the structure of the ligand bound to boron, the optical and electronic properties of a compound can be precisely tuned for unique properties, such as aggregation‐induced emission (AIE) in the case of boron difluoride hydrazones (BODIHYs). We examine the impact of modifying the typical bidentate hydrazone ligand structure used to prepare BODIHYs to enable a tridentate coordination mode to produce boron complexes of tridentate acyl pyridylhydrazones. This change allows for the use of arylboronic acids as sources of boron and facilitates the inclusion of complex organic components at the boron centre, including the formation of dye‐dye conjugates. The synthesized compounds exhibit distinct optical and electronic properties when compared to BODIHYs, such as reversible electrochemical reduction and up to a >300 nm pseudo‐Stokes shift in the solid state, all of which were supported by density functional theory calculations. [ABSTRACT FROM AUTHOR]

Herein we report the first microwave‐assisted one‐pot three‐step metal‐free [4+2] procedure for the synthesis of 5,6‐substituted‐3‐hydrazinyl‐1,2,4‐triazines directly from commercially available aromatic and heteroaromatic ketones. The 3‐hydrazinyl‐1,2,4‐triazine can be isolated or further elaborated, after a simple work‐up, by direct condensation with different aldehydes or ketones to provide highly functionalized hydrazone‐derivatives. This protocol represents a rapid, efficient, and sustainable approach for the development of new highly functionalized 1,2,4‐triazine derivatives with potential biological interest. [ABSTRACT FROM AUTHOR]

(1) Background: The aim of the work is the evaluation of in vitro antiproliferative and pro-apoptotic activity of four benzimidazole derivatives containing colchicine-like and catechol-like moieties with methyl group substitution in the benzimidazole ring against highly invasive breast cancer cell line MDA-MB-231 and their related impairment of tubulin dynamics. (2) Methods: The antiproliferative activity was assessed with the MTT assay. Alterations in tubulin polymerization were evaluated with an in vitro tubulin polymerization assay and a docking analysis. (3) Results: All derivatives showed time-dependent cytotoxicity with IC50 varying from 40 to 60 μM after 48 h and between 13 and 20 μM after 72 h. Immunofluorescent and DAPI staining revealed the pro-apoptotic potential of benzimidazole derivatives and their effect on tubulin dynamics in living cells. Compound 5d prevented tubulin aggregation and blocked mitosis, highlighting the importance of the methyl group and the colchicine-like fragment. (4) Conclusions: The benzimidazole derivatives demonstrated moderate cytotoxicity towards MDA-MB-231 by retarding the initial phase of tubulin polymerization. The derivative 5d containing a colchicine-like moiety and methyl group substitution in the benzimidazole ring showed potential as an antiproliferative agent and microtubule destabilizer by facilitating faster microtubule aggregation and disrupting cellular and nuclear integrity. [ABSTRACT FROM AUTHOR]

Heterocycles that pair main group elements and nitrogen are extremely important within the π‐conjugated heterocycles research community. Compared to the vast number of boron‐nitrogen heterocycles, those that include phosphorus are less common. Furthermore, the use of phosphorus‐nitrogen triple bonds of any type to prepare such compounds is unprecedented. Here, we pair pyridyl hydrazonide ligands with phosphadiazonium cations and demonstrate that the chelated Mes*NP group is directly implicated in the photophysical and redox properties observed for the resulting heterocycles. In doing so, we introduce a novel building block for the production of phosphorus‐containing heterocycles that could find use in small molecule activation and catalysis or as the functional component of emerging organic electronics. [ABSTRACT FROM AUTHOR]

The necessity of the development of compounds with effectiveness in therapy against infective diseases has increased in the last 3 years in connection with the spread of COVID-19. The current study aimed to summarize the pharmacological activities of metal-based organic compounds against different viral diseases, including COVID-19. A systematic literature review was carried out by using data sources in Medline, Pub Med, SCOPUS, and Science Direct. The used methods were collecting data, summarizing, and analyzing information. Antiviral properties exert metal complexes with ligands, such as: hydrazones; thiosemi-carbazones: Pt(II), Pd(II); Ga(III); Pd(II); Co(III), Ni(II), Cu(II)); fluoroquinolones, quinoline: Pd(II); phenylquinoline, phenylpyridine; tetrahydropyrimidines: Ag(I); phenanthroline: Cu(II); Valacyclovir: Cu(II)). Complexes of Zn(II). Co(II), Cu(II), Ni(II), Mg(II), Mn(II), and Zn(II) exert antiviral effects against the DNA Herpes simplex viruses HSV-1, HSV-2. Co(II), effective towards the HIV are complexes of the following metals: Au(II), Co(II), Cu(II), Fe(III), La(III), Mg(II). Ni(II), Pd(II), Pt(II), Ru(II). Against the HIV have been described to be active complexes of the following metals: Au(II), Co(II), Cu(II), Fe(III), La(III), Mg(II), Ni(II), Pd(II), Pt(II), and Ru(II). In connection with the continued spread of the severe acute respiratory syndrome – Coronavirus 2 (SARS-CoV-2), today's very actual strategy is the development of effective COVID therapeutics. The perspective trend in the creation and investigation of potential agents for the effective application towards SARS-CoV-2, are Auranofin and Cu(II), Ni(II), Mn(II), and Zn(II) complexes of Coumarin. [ABSTRACT FROM AUTHOR]

Pyridoxal and pyridoxal 5′-phosphate are aldehyde forms of B6 vitamin that can easily be transformed into each other in the living organism. The presence of a phosphate group, however, provides the related compounds (e.g., hydrazones) with better solubility in water. In addition, the phosphate group may sometimes act as a binding center for metal ions. In particular, a phosphate group can be a strong ligand for a gold(III) ion, which is of interest for researchers for the anti-tumor and antimicrobial potential of gold(III). This paper aims to answer whether the phosphate group is involved in the complex formation between gold(III) and hydrazones derived from pyridoxal 5′-phosphate. The answer is negative, since the comparison of the stability constants determined for the gold(III) complexes with pyridoxal- and pyridoxal 5′-phosphate-derived hydrazones showed a negligible difference. In addition, quantum chemical calculations confirmed that the preferential coordination of two series of phosphorylated and non-phosphorylated hydrazones to gold(III) ion is similar. The preferential protonation modes for the gold(III) complexes were also determined using experimental and calculated data. [ABSTRACT FROM AUTHOR]

Despite efforts, available alternatives for the treatment of leishmaniasis are still scarce. In this work we tested a class of 15 quinolinylhydrazone analogues and presented data that support the use of the most active compound in cutaneous leishmaniasis caused by Leishmania amazonensis. In general, the compounds showed activity at low concentrations for both parasitic forms (5.33–37.04 μM to promastigotes, and 14.31–61.98 μM to amastigotes). In addition, the best compound (MHZ15) is highly selective for the parasite. Biochemical studies indicate that the treatment of promastigotes with MHZ15 leads the loss of mitochondrial potential and increase in ROS levels as the primary effects, which triggers accumulation of lipid droplets, loss of plasma membrane integrity and apoptosis hallmarks, including DNA fragmentation and phosphatidylserine exposure. These effects were similar in the intracellular form of the parasite. However, in this parasitic form there is no change in plasma membrane integrity in the observed treatment time, which can be attributed to metabolic differences and the resilience of the amastigote. Also, ultrastructural changes such as vacuolization suggesting autophagy were observed. The in vivo effectiveness of MHZ15 in the experimental model of cutaneous leishmaniasis was carried out in mice of the BALB/c strain infected with L. amazonensis. The treatment by intralesional route showed that MHZ15 acted with great efficiency with significantly reduction in the parasite load in the injured paws and draining lymph nodes, without clinical signs of distress or compromise of animal welfare. In vivo toxicity was also evaluated and null alterations in the levels of hepatic enzymes aspartate aminotransferase, and alanine aminotransferase was observed. The data presented herein demonstrates that MHZ15 exhibits a range of favorable characteristics conducive to the development of an antileishmanial agent. [ABSTRACT FROM AUTHOR]

A photocatalytic radical carbophosphorylation/cyclization of N-homoallyl aldehyde hydrazones with phosphine oxides was developed under metal-free conditions, achieving phosphorylated tetrahydropyridazines in yields up to 95%. Phosphorylated dihydropyrazoles were also constructed, by reacting N-allyl aldehyde hydrazones with phosphine oxides under the same conditions. [ABSTRACT FROM AUTHOR]

Synthesis of nitro-substituted [1,2,4]triazolo[1,5-a]pyrimidines based on oxidative cyclization of the corresponding nitropyrimidinyl hydrazones of aromatic aldehydes was developed. The reactions of 2-aryl-6-nitro-[1,2,4]triazolo[1,5-a]pyrimidines and their structural analogs (2-aryl-6,8-dinitro-[1,2,4]triazolo[1,5-a]pyridines) with different C-nucleophiles were studied. Nucleophilic addition to the pyridine and pyrimidine rings carried out under mild base-free conditions gave new stable 1.5-dihydro-[1,2,4]triazolo [1,5-a]-pyridines and 1.5-dihydro-[1,2,4]triazolo[1,5-a]pyrimidines in the yields up to 94%. [ABSTRACT FROM AUTHOR]

N-(Iminyl)pyridinium salts are a rare and poorly explored class of pyridine derivatives. In this work, we propose a method for the synthesis of these compounds from methyl nicotinate and hydrazones of aromatic ketones. The method involves N-arylation of pyridine with 2,4-dinitrophenol tosylate and subsequent reaction of the arylpyridinium salt with the amino group of N-unsubstituted hydrazones (the Zincke reaction). [ABSTRACT FROM AUTHOR]

Given the importance of molecular structure in pharmacological activity and interaction with biological receptors, we conducted a study on the 3,4-dihydroxybenzaldehyde hydrazone derivative of 5-methoxy-indole carboxylic acid (5MICA) and a newly synthesised analogue bearing a 2-methoxy-4-hydroxyphenyl ring using single-crystal X-ray diffraction. We studied the ability of the two compounds to scavenge hypochlorite ions using luminol-enhanced chemiluminescence and their potential to modulate oxidative damage induced by iron on the biologically significant molecules lecithin and deoxyribose in order to evaluate possible antioxidant and prooxidant effects. The X-ray study revealed highly conserved geometry and limited rotation and deformation freedom of the respective indole and phenyl fragments. Interestingly, a conformational difference between the two independent molecules in the asymmetric unit of 3b was found. The X-ray study revealed a combination of hydrogen bonding interactions, short contacts, and π–π stacking stabilizing the specific three-dimensional packing of the molecules of 3a and 3b in the crystal structures. The three-dimensional packing of the molecules of 3b produced a zigzag layering projected along the c-axis. Both compounds effectively decreased luminol-dependent chemiluminescence in model systems with KO2-produced superoxide. They displayed opposite effects when applied in a xanthine/xanthine oxidase system. The hydrazones of 5MICA do not trigger a prooxidant effect or subsequent toxicity under conditions of iron-induced oxidative stress. The 3,4-dihydroxy-substituted derivative demonstrated excellent radical scavenging properties in all model systems, making it the lead compound for the development of compounds with combined neuroprotective and antioxidant properties. [ABSTRACT FROM AUTHOR]

As a type of elementary organic compounds containing N−N single bond, hydrazone involved chemical conversions are extremely extensive, but they are mainly limited to N2‐retention and N2‐removal modes. We report herein an unprecedented protocol for the realization of division utilization of the N2‐moiety of hydrazone by a radical facilitated N−N bond deconstruction strategy. This new conversion mode enables the successful combination of alkene carboamination and Hofmann‐Löffler‐Freytag reaction by the reaction of N‐homoallyl mesitylenesulfonyl hydrazones with ethyl difluoroiodoacetate under photocatalytic redox neutral conditions. Mechanism studies reveal that the reaction undergoes a radical relay involving addition, crucial remote imino‐N migration and H‐atom transfer. Consequently, a series of structurally significant ϵ‐N‐sulphonamide‐α,α‐difluoro‐γ‐amino acid esters are efficiently produced via continuous C−C bond and dual C−N bonds forging. [ABSTRACT FROM AUTHOR]

A new series of 2H‐chromene‐based hydrazones (10 a–w, 12 a–d, and 14 a–d) were efficiently synthesized by the reaction of substituted 2H‐chromene aldehydes (8 a–w) with various hydrazines (9, 11, and 13) in absolute ethanol under microwave irradiation as well as by lemon juice mediated conventional heating. The structures of synthesized target molecules were identified by spectroscopic analysis methods (1H NMR, 13C NMR, FT‐IR, and HRMS). The in vitro anticancer activity of the new 2H‐chromene‐based hydrazones were evaluated on the three breast cancer cell lines (MCF‐7, MDA MB‐231, and MDA MB‐468) by MTT assay. Among these synthesized compounds, 10 r and 12 b exhibited the most potent antiproliferative activities with IC50 values at 9.12±0.45 μM and 10.71±0.67 μM respectively, against MCF‐7 cell. Flowcytometric analysis revealed that these two potent compounds, 10 r and 12 b arrested the cell cycle at the G2/M phase and induced apoptosis of proteins in a dose‐dependent manner. It was further confirmed by Hoechst staining and Annexin V‐FITC assay. Additionally, compounds 10 r and 12 b were examined by in silico molecular docking, which revealed that compound 10 r displayed excellent binding affinity energy of around −10 kcal/mol with human HER2 receptor. Also, the ADME studies validated the hybrid compounds showing promising physicochemical, pharmacokinetic, and drug‐like attributes. Broadly, these results underscored the potential of 2H‐chromene‐based hydrazone derivatives as promising anticancer agents. [ABSTRACT FROM AUTHOR]

Water-soluble ammonium salts were prepared by the reaction of new sterically hindered isatin derivatives with analogues of Girard's reagents. The resulting isatin-3-hydrazones exhibit high antimicrobial and antiaggregation activity with low hemotoxicity. The dependence of physiological activity on the volume of the benzyl substituent was established. [ABSTRACT FROM AUTHOR]

One of the most serious threats to human health is the increasing prevalence of drug-resistant pathogens. The development of new antibiotics capable of combating drug resistance is critical. In various bacteria and plant species, 4-aminobenzoic acid (PABA) is produced and used as a substrate for folate generation. In this study, a new series of PABA analogs were synthesized and evaluated for their antimicrobial activity. Thirteen novel compounds were prepared by linking PABA hydrazide to sulfonate esters via a hydrazone bridge (4a–m). The structures of these compounds were characterized by 1H and 13C NMR and FT-IR spectroscopy as well as by LC-MS. Following structural characterization, all compounds were tested for their antimicrobial activity against Staphylococcus aureus (ATCC 29213), Enterococcus faecium (ATCC 19434), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), and Candida albicans (ATCC 10231) strains. Four compounds were found to have moderate antimicrobial activity against the P. aeruginosa strain. These compounds, including 4e, 4f, 4g, and 4m, containing a hydrazide-hydrazone sulfonate functionality, showed the best MIC value of 64 μg/mL. In addition, synergistic effects of ascorbic acid, salicylic acid, and N-acetyl cysteine (NAC) with synthesized compounds were also investigated. It was observed that the combination of compounds 4f and 4g with NAC showed antipseudomonal activity with MIC values of 32 μg/mL and 16 μg/mL, respectively, against the P. aeuriginosa strain. The antimicrobial activity of 4f and 4g was enhanced by two folds in combination with NAC. Our findings in this study can be crucial for the development of new potent antimicrobial agents. [ABSTRACT FROM AUTHOR]

The reaction of acetyl-containing furan-3-carboxylates with substituted hydrazines in an alcohol solution leads to the formation of substituted furan-3-carboxylate hydrazones. The resulting hydrazones have E-configuration, as determined by NMR spectroscopy and X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

A convenient visible–light–promoted phosphorylation reaction of α‐diazoesters with H‐phosphine oxides for the preparation of (Z)‐phosphinic hydrazones has been explored. This reaction could be performed under mild conditions to afford a series of (Z)‐phosphinic hydrazones in moderate to good yields through photoisomerization of C=N bond. [ABSTRACT FROM AUTHOR]

[Display omitted] Reaction of 3-hydroxy-2,5-di- tert -butyl-1,4-benzoquinone with phenylhydrazine hydrochloride mainly leads to the corresponding hydrazone at the position 1 existing in tautomeric equilibrium with 3,6-di- tert -butyl-4-(phenyl- diazenyl)catechol. Thermodynamic parameters of the tautomerization were evaluated by NMR spectroscopy. The hydrazone structure was confirmed by XRD study. [ABSTRACT FROM AUTHOR]

A novel series of 1,3,4-oxadiazole derivatives of mefenamic acid was obtained by reacting hydrazones of mefenamic acid with anhydrous acetic anhydride. The mefenamic hydrazones were obtained by reacting different substituted aldehydes with mefenamic acid hydrazide. All the compounds were characterized by spectral data and elemental analysis. Molecular docking studies of all the compounds were performed against COX-1/COX-2 enzymes. Compound 4 and compound 10 were found to have the highest potential to bind with COX-1 while compound 3, compound 6, and compound 10 were found to have the highest potential to bind with COX-2 enzyme.

Fluorinated imines (Schiff bases) and fluorinated hydrazones are of particular interest in medicinal chemistry due to their potential usefulness in treating opportunistic strains of bacteria that are resistant to commonly used antibacterial agents. The present review paper is focused on these fluorinated molecules revealing strong, moderate or weak in vitro antibacterial activities, which have been reported in the scientific papers during the last fifteen years. Fluorinated building blocks and reaction conditions used for the synthesis of imines and hydrazones are mentioned. The structural modifications, which have an influence on the antibacterial activity in all the reported classes of fluorinated small molecules, are highlighted, focusing mainly on the importance of specific substitutions. Advanced research techniques and innovations for the synthesis, design and development of fluorinated imines and hydrazones are also summarized. [ABSTRACT FROM AUTHOR]

A Pd‐catalyzed heterocyclization/carbonylation/arylation cascade reaction between β,γ‐unsaturated N−Ts hydrazones and commercially available arylboronic acids as coupling partners is described, producing 2‐pyrazoline‐ketone derivatives in 11–78% yield. A detailed statistical analysis of reactivity patterns of boronic acids provided key information about the limitations of the method, highlighting the challenges of degradation pathways. Our methodology offers a tool for synthesizing diverse 2‐pyrazoline‐ketone derivatives, expanding the toolbox of accessible N−N‐heterocycles. [ABSTRACT FROM AUTHOR]

New ammonium hydrazones have been synthesized by the reaction of Girard's reagents T and P with isatin derivatives that contain various alkyl or geranyl substituents in position 1. A pronounced anti-anthropo- and antiphyto-pathogenic effect of resulting compounds has been revealed. The n-octyl and octadiene derivatives have the highest selectivity for resistant strains of Staphylococcus aureus when there is no negative effect on the hemostasis system. The aggregation and adsorption properties of the compounds have been studied using tensiometry, conductometry, and UV spectroscopy. The found values of the critical micelle concentration of amphiphilic ammonium hydrazones are an order of magnitude lower than those of quaternary ammonium salts. [ABSTRACT FROM AUTHOR]