Investigation of O-phenacyl ethers of N-arylquinone imines intramolecular cyclization has demonstrated that it could proceed via two possible pathways: the C-C-bond formation or C-N bond formation, yielding 1,4-benzox-azines or 1,3-benzoxazoles. It has been established that the key factor determining the pathway of the cyclization reaction is the nature of the substituent in the phenyl ring of the benzoyl fragment of O-phenacyl ethers of N-arylquinone imine. The presence of an acceptor substituent leads to the formation of spirooxazine, whereas the absence of a substituent or the presence of a significant donor effect leads to the formation of oxazole product. The structures of the obtained compounds were studied by HRMS and NMR spectroscopy, including various twodimensional NMR techniques. The structural features of four benzoxazine compounds, one benzoxazolone, and two by-products were studied in detail using single crystal X-ray diffraction analysis. Intermolecular interactions and cavities in crystals of spirocyclohexadienes of the 1,4-benzoxazines series were studied using the CrystalExplorer 21.5 software package.

This study reports the synthesis and comprehensive characterization of two novel dinuclear copper(II) complexes derived from 2-(5-methoxy-1-methylbenzimidazol-2-yl)-1-(4-methoxyphenyl)ethanol (HL). The reaction of HL with copper(II) acetate hydrate and copper(II) nitrate trihydrate in tetrahydrofuran yielded dinuclear complexes formulated as [CuL(CH3COO)]2 & sdot;2MeCN (1) and [CuLH(NO3)DMF]2 & sdot;DMF (2), respectively. The compounds were characterized by elemental analysis, IR and 1H NMR spectroscopy, and single-crystal X-ray diffraction analysis. Structural elucidation revealed that both complexes feature a Cu2O2 rhombic core with the copper centers bridged by alkoxide oxygen atoms. Magnetic susceptibility measurements in the temperature range of 5-300 K demonstrated strong antiferromagnetic exchange interactions in both complexes, with exchange coupling constants of J =-401 +/- 11 cm-1 for 1 and J =-445 +/- 5 cm-1 for 2. Broken-symmetry density functional theory (BS-DFT) calculations corroborated the experimental magnetic data and provided insight into the electronic structure and magnetic exchange pathways. The observed differences in magnetic behavior are discussed in relation to structural variations induced by the different coordinating anions.

N-(3′,5′-Di-tert-butyl-4′-hydroxyphenyl)-N-(2″-hydroxyphenyl)-4-nitrobenzamide was found to be an alternative product in the cyclization reaction of O-(4-nitrobenzyl) ether of N-phenylquinone imine proceeding through the formation of a benzoxazole ring. The structure of the product was established by 1H and 13C NMR spectroscopy, high-resolution MS spectrometry, and X-ray diffraction analysis. Quantum chemical calculations of plausible mechanism of the formation of this compound were carried out.

Preliminary ab initio calculations led to the synthesis of novel substituted thiazolium salts, analogs of Alagebrium, which were further explored in vitro for their potential as inhibitors of the glycation reaction utilizing three distinct assays: inhibition of fluorescent AGEs formation, anticrosslinking, and deglycation. Despite the unidirectionality of the assays, distinct differences were observed in the mechanisms of interference and activity manifestation by the compounds. The gathered data permitted the formation of hypotheses about the molecular fragments of the studied antiglycators that are of utmost significance in each assay, thereby guiding future design endeavors. Potential mechanisms of actions are discussed therein. The compound 4-meth-yl-3-[2-(4-methylbiphenyl-4-yl)-2-oxoethyl] thiazolium bromide displayed high activity across all three assays, establishing it as a lead compound. The cytotoxicological properties of the compounds were evaluated using LDH and MTT assays. However, the lead compound exhibited cytotoxicity, indicating the need for additional investigations aimed at decreasing toxicity while maintaining activity. The targeted thiazolium salts were synthesized through an N -alkylation reaction between the corresponding thiazoles and phenacyl bromides.

We investigated the reactivity of various furans towards 2-azidobenzaldehydes, heterocyclic azidoaldehydes, and substituted 2-azidobenzyl alcohols to synthesize 2-(2-azidobenzyl)furan derivatives, revealing the azide group's remarkable compatibility with typical Friedel-Crafts reaction conditions. Additionally, we demonstrated that these derivatives could be efficiently synthesized via a diazotization/azidation sequence from 2-(2-aminobenzyl)furans containing electron-donating substituents, successfully avoiding undesirable side reactions. Furthermore, we developed a synthetic methodology for preparing 2-(2-acylvinyl)indoles, involving the thermal generation of nitrenes to initiate furan ring opening. Notably, our approach utilizes the azidoaryl group and the furan ring separated by a saturated carbon atom that distinguishes it from known indole syntheses in which these moieties are conjugated. The broad applicability and high efficiency of our method, using readily available starting materials, highlight its potential as a versatile synthetic tool.

An efficient approach to the synthesis of novel 2,3-diaryl-3,4-dihydro-2H-benzo[4,5]imidazo[2,1-b][1,3,4]thiadiazines via a base-catalyzed intramolecular cyclization of 2-arylmethylthio-N-arylidene-1H-benzo[d]imidazol-1-amines has been developed. The use of alkali is critical for the annulation of the thiadiazine ring. In the absence of strong bases, the starting compounds undergo deamination with elimination of benzonitrile and formation of 2-arylmethylthiobenzimidazoles.

The acid-catalyzed reaction of 4-chloro-2,7-dimethyl- 1,8-naphthyridine with 4,6-di-tert-butyl-3-nitro-1,2-benzoquinone leads to new bis-1,3-tropolones. The crystal structures of the obtained bis-1,3-tropolones were determined by X-ray diffraction analysis; the spectral and luminescent properties, the structural and energy characteristics of the compounds were examined. The cytotoxic effect in vitro against cancer cell lines A549, H1299, HT29, CT26 and B16F10 was assessed using MTT assay.

By the condensation of 4-amino-5-R-2,4-dihydro-3H-1,2,4-triazole-3-thiones with anthracene-9- carbaldehyde, respective 4-[(anthracene-9′-ylmethylene)amine)]-5-R-2,4-dihydro-3H-1,2,4-triazole-3-thiones are prepared and structurally characterized by NMR, UV, IR spectroscopies, high-resolution mass spectrometry, and single crystal XRD. The effect of a substituent at position 5 in triazole moieties of azomethines obtained on their head-to-head or head-to-tail crystal packings is determined.

A series of novel Zn(II) bischelate complexes based on azomethines of 2-(N-tosylamino)benzaldehyde and aromatic amines (aniline, 4-methylaniline, 4-methoxyaniline, 2-methoxylaniline, and 4-ethoxylanine) were designed and synthesized with the aim of studying their photo- and electro-luminescent properties. The structures of the synthesized azomethines and their complexes were studied by elemental analysis, infrared (IR) and proton nuclear magnetic resonance (1H NMR) spectroscopy. The structure of the Zn(II)-complexes was determined using X-ray diffraction analysis. In the solid state, azomethines exhibit bright luminescence in the yellow part of the spectrum with high emission efficiency and quantum yields of approximately 50 %. Zinc complexes based on them exhibit noticeable luminescence in the solid state and in solutions of methylene chloride. Compared to azomethines, the luminescence maxima of Zn(II) complexes are hypsochromically shifted, and they exhibit pronounced blue-green luminescence. The OLED devices based on zinc(II) complexes emit strong bluishgreen light with a peak maximum at 478-490 nm. The device with the best parameters has a maximum luminance of 2103 cd/m2, a current efficiency of 14.0 cd/A, and an overall efficiency of 4.8 %, with a turn-on voltage of 3.6 V.

Mono-, di-, and trifluorophenyl substituted in different positions of amine fragments bis [2-[[(E)-((fluorophenyl)iminomethyl]-N-(p-tolylsulfonyl)anilino]zinc(II) complexes were synthesized. Their crystal structure, photo- and electroluminescent properties, and protistocidal, fungistatic, and antibacterial activities were studied. It has been shown that the introduction of fluorine atoms and an increase in their number in the ligand structure of the resulting metal complexes promote the luminescence quantum yields and values of performance and brightness in EL cells compared to their previously studied chlorine-substituted analogs.

Two new Schiff base compounds of N‐{2‐[(E)‐сyclohexyliminomethyl]phenyl}‐4‐methylbenzenesulfonamide, N‐{2‐[(E)‐(4‐сyclohexylphenyl)iminomethyl]phenyl}‐4‐methylbenzenesulfonamide and their Zn(II) complexes have been synthesized and characterized by elemental analysis, FT‐IR and UV–Vis spectra, and single crystal X‐ray determination. In both complexes, Zn2+ ions have a tetrahedral environment with two nitrogen atoms of the tosylamide groups and two nitrogen atoms of the imine fragment. Time‐dependent density functional theory calculations have been performed on two zinc(II) complexes in order to assign their experimental UV–visible absorption bands. Zinc(II) complexes showed thermal stability up to 335–340°C under a nitrogen atmosphere by thermogravimetric analysis (TGA). The photoluminescent spectra show that both Zn(II) complexes in the solid state at room temperature emit blue luminescence with high emission quantum yields of 20% and 29%. The doped devices with configurations of indium tin oxide (ITO)/poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/N,N′‐Di(1‐naphthyl)‐N,N′‐diphenyl‐(1,1′‐biphenyl)‐4,4′‐diamine (NPD)/4,4′‐N,N′ ‐dicarbazolebiphenyl (CBP):Zinc(II) complex (5%)/1,3,5‐tris(N‐phenylbenzimidazole‐2‐yl) benzene (TPBI)/LiF/Al have been fabricated and investigated. The doped device based on the complex with the сyclohexylphenyl substituent of the ligand showed the best electroluminescent characteristics with maximum brightness Lmax of 3415 cd/m2, maximum current efficiency of 2.8 cd/A, and power efficiency of 1.9 lm/W, while the doped device with emitter on the base of the complex with the сyclohexyl substituent showed slightly worse electroluminescence (EL) performance with Lmax of 2105 cd/m2, maximum current efficiency of 2.1 cd/A, and power efficiency of 1.6 lm/W.

Конденсацией 4-амино-5-R-2,4-дигидро-3H-1,2,4-триазол-3-тионов с антрацен-9-карбальдегидом были получены соответствующие 4-[(антрацен-9‵-илметилен)амин)]-5-R-2,4-дигидро-3H-1,2,4-триазол-3-тионы, которые структурно охарактеризованы с привлечением методов спектроскопии ЯМР, УФ, ИК, масс спектрометрии высокого разрешения и РСА. Установлено влияние заместителя в положении 5 триазольного фрагмента полученных азометинов на их кристаллическую упаковку «голова к голове» или «голова к хвосту».

The S(O,N)-benzyl ethers of N-arylquinone imines undergo cyclization under the action of bases to form products of the benzothiazol, benzoxazole, and benzimidazole series, while under thermal conditions they undergo a non-catalyzed rearrangement to form spiro-cyclohexadiene derivatives of benzazines. The benzimidazole, spirobenzothiazine, and spirobenzoxazine structures were supported by the x-ray diffraction method. The possibility of intramolecular photochemical cyclization was investigated; ortho-S(O,N)-benzyl-substituted N-arylquinone imines show high photostability under UV irradiation. The features of the cyclization processes of quinone imine derivatives were revealed by DFT calculations using the wB97XD/6-311++G** method.

This work describes the synthesis of series hydrobromides of N-(4-biphenyl)methyl-N'-dialkylaminoethyl-2-iminobenzimidazoles, which, due to the presence of two privileged structural fragments (benzimidazole and biphenyl moieties), can be considered as bi-privileged structures. Compound 7a proved to activate AMP-activated kinase (AMPK) and simultaneously inhibit protein tyrosine phosphatase 1B (PTP1B) with similar potency. This renders it an interesting prototype of potential antidiabetic agents with a dual-target mechanism of action. Using prove of concept in vivo study, we show that dual-targeting compound 7a has a disease-modifying effect in a rat model of type 2 diabetes mellitus via improving insulin sensitivity and lipid metabolism.

2,3-Dihydro-1H-imidazo[1,2-a]benzimidazole in acetic acid, and its N-1-Me derivative in CHCl3, are brominated at position 6 with bromine. Less nucleophilic N-9-R derivatives do not enter into the reaction under these conditions, but, like their N-1-R isomers, they are quite effectively brominated by the KBrO3-HBr system, but at position 7, probably due to the transition of the reaction to the mode of bromination of protonated forms of substrates. N-1- and N-9-alkyl-6(7)-Br-2,3-dihydroimidazo[1,2-a]benzimidazoles can also be obtained by N-alkylation of 6(7)-Br-2,3-dihydroimidazo[1,2-a]benzimidazoles under neutral or basic conditions.

Quinazolin-4(3Н)-one derivatives are characterized by a wide range of pharmacological properties, among which the most significant one is a pronounced effect on the central nervous system. In this regard, a molecular design of biologically active compounds that have an analgesic activity due to the formation of ligand-receptor complexes with nociceptive and dopamine receptors, has been performed. The aim of the study was a molecular design and a subsequent targeted synthesis of 2-phenyl- and 2-benzyl derivatives of 4(3H)-quinazolinone with an analgesic activity, as well as the creation of a mathematical model in order to identify significant molecular descriptors. Materials and methods. A molecular design was carried out by a logical-structural approach using the PASS program with the identification of the biological activity of the predicted structures, as well as the energy calculation of the ligand-receptor interaction. The synthesis of 2-phenyl derivatives of 4(3H)-quinazolinone was carried out by the reaction of 2-aminobenzamide with aromatic aldehydes in polyphosphoric acid when heated, while the 2-benzyl derivatives were synthesized by fusing amides of anthranilic and homoveratric acids followed by sulfonation with sulfuric acid. The analgesic activity of the synthesized compounds was studied in the models of nociceptive reactions induced by chemical stimuli (a formalin test and “acetic acid writhings”). Results. A molecular design made it possible to identify promising structures in the series of 4(3H)-quinazolinone derivatives that affect nociceptive and dopamine receptors and have an analgesic activity. A modification was made to the synthesis of 2-phenyl- and 2-benzyl derivatives of 4(3H)-quinazolinone in order to increase the yield of the target products by a simpler and more cost-effective method. The predicted compounds were synthesized by cyclocondensation of anthranilic acid amide with aromatic aldehydes or with homoveraic acid amide. It follows from the primary pharmacological studies results that the synthesized substances are promising from the point of view of creating painkillers based on them. A structure-activity relationship between the molecular descriptors, which are largely responsible for the analgesic activity, and the results of biological tests, has been revealed. Conclusion. The use of computer modelling made it possible to identify the amino acid residues involved in the formation of the ligand-receptor complex with the nociceptive receptor, and to construct a mathematical model to explain the analgesic activity of 2-phenyl- and 2-benzyl derivatives of 4(3H)-quinazolinone. Modified procedures for the synthesis of target compounds have been proposed. The obtained coefficients of the approximation between the theoretical values and the data of the pharmacological experiment make it possible to state a sufficient reliability of the carried out studies.

This microreview discusses the latest examples (2012–2022) of the synthesis of pyrazolo[3,4- d ]-thiazoles, pyrazolo[4,3- d ]thiazoles, pyrazolo[4,3- b ][1,4]thiazines, and pyrazolo[3,4- b ][1,4]-thiazines via two main approaches: annulation of the pyrazole ring to the thiazole or thiazine ring and, conversely, annulation of the thiazole or thiazine ring to the pyrazole ring.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Two Zn(II) and Ni(II) complexes derived from the N-[2-(2-diethylphosphonylethyliminomethyl)phenyl]-4methylbenzenesulfonamide ligand (HL) with stoichiometry ML2 (M = Zn, Ni) have been synthesized. Their structures have been established using elemental analysis, IR, 1H NMR, UV-Vis spectroscopy, and synchrotron single-crystal X-ray diffraction. The Zn(II) and Ni(II) metal sites therein adopt the tetrahedral configuration. The DMSO and toluene solutions of the Zn(II) complex manifest photoluminescence in the blue-violet spectral range characterized by PL maxima at 436 and 432 nm and quantum yields of 0.15 and 0.30, respectively.

Isonicotinic acid N′-(10-oxo-10H-phenanthren-9-ylidene)hydrazide (HL) and its complexes ML2 and MHLCl2 [М = Cu(II), Ni(II), Co(II), Fe(II), and Zn(II)] were synthesized. The structure and properties of the obtained compounds were studied by 1H NMR, IR, and X-ray absorption spectroscopy. The hydrazide structure was determined by X-ray diffraction. Quantum-chemical calculations of its tautomeric forms and electronic absorption spectra were carried out. In ML2 chelate complexes, the ligand is coordinated to metal atoms in the enol form, whereas in MHLCl2 complexes it is coordinated in the keto form.