Vol 89, No 11 (2019)
- Year: 2019
- Articles: 26
- URL: https://journals.rcsi.science/1070-3632/issue/view/13716
Article
Benzene Alkylation with Cycloolefins under the Action of [Et3NH]+[Al2Cl7]− Ionic Liquid
Abstract
Benzene alkylation with mono- and bicyclic olefins under the action of an inorganic ionic liquid [Et3NH]+[Al2Cl7]− with the formation of benzene cycloalkyl derivatives in 58–98% yield has been performed for the first time. It has been found that the increase in the olefin cycle size improves the selectivity with respect to monocycloalkyl derivatives.
Synthesis of Phthalic Aldehyde and Its Diacetals
Abstract
Acyclic phthalaldehyde diacetal without cyclic 1,3-dihydro-1,3-dimethoxybenzo[c]furan impurity has been obtained via the reaction of 1,2-bis(dibromomethyl)benzene with trimethyl orthoformate (1:6) at 90°C in the presence of 10 mol% of ZnCl2. Hydrolysis of phthalaldehyde diacetal has led to the formation of phthalaldehyde without HBr evolution. The reaction of phthalaldehyde with trimethyl orthoformate in the presence of trifluoroacetic acid has proceeded abnormally, with the formation of the cyclic diacetal. The acyclic diacetal has been phosphorylated by chlorophosphines and the action of PCl3 and a P(III) acid ester in sequence.
Pyridoxal Azomethine Salts
Abstract
The reactions of 4-methylpiperazin-1-amine, 2-amino- and 4-aminomethylpiperidines with pyridoxal afforded the corresponding azomethines. Their reactions with organic and inorganic acids lead to the formation of salt derivatives of pyridoxal azomethines.
Synthesis and Fungicidal Activity of Substituted N-(Alkoxy)-1-(3-pyridinyl)methanonimines
Abstract
A number of new substituted N-(alkoxy)-1-phenyl- and N-(alkoxy)-1-cyclohexyl-1-(3-pyridinyl)-methanonymines were prepared by reacting the corresponding N-hydroxyl derivatives with benzyl chloride under phase transfer catalysis in a 10% NaOH-benzene system, as well as with 1-bromohexane and bromocyclohexane in DMF in the presence of NaH. The fungicidal activity of the obtained compounds was studied in vitro towards phytopathogenic fungi Venturia inaequalis, Rhizoctonia solani, Fusarium oxysporum, F. moniliforme, and Helminthosporium sativum.
Synthesis and Some Transformations of 7-Substituted 8-Chlorotheophyllines
Abstract
Alkylation of 8-chlorotheophylline by alkenyl(propargyl) halides yields 7-alkenyl(propargyl)-8-chlorotheophyllines. The reaction of 8-chlorotheophylline with 1,3-dichloropropan-2-ol leads to the formation of oxazolo[2,3-f]purinium system. 7-Alkenyl-8-chlorotheophyllines react with bromine to give dibromoalkyl-8-chlorotheophyllines. The reaction of 7-methallyl-8-chlorotheophylline with m-chloroperbenzoic acid affords the corresponding oxirane.
Tri-n-butylphosphine-Catalyzed Phosphonoethylation Reactions of Hydrophosphoryl Compounds
Abstract
An efficient method for the synthesis of 1,2-bisphosphoryl compounds based on the addition of hydrophosphoryl derivatives to O,O-diethyl vinylphosphonate was developed. The reaction proceeds in mild conditions under catalysis with tri-n-butylphosphine and leads to the formation of the corresponding target products with high yield.
One-Step Synthesis of Phosphorylated Vinylacethylene Derivatives
Abstract
A one-step method for the preparation of 3-substituted 2-(diethylphosphoryl)but-1-en-3-ynes was developed based on the reaction of phosphorylated α-allene alcohols with methanesulfonic anhydride in the presence of triethylamine. The obtained vinylacetylene derivatives are of interest as promising precursors for the creation of organophosphorus heterocyclic compounds.
Some Features of Reaction of 2-Methyl-1,4-naphthoquinone with H-Phosphonium Salts Based on Diphenylphosphine
Abstract
It was shown that the direction of the reaction of 2-methyl-1,4-naphthoquinone with H-phosphonium salts obtained from diphenylphosphine and trifluoromethanesulfonic or trifluoroacetic acids depends on the nature of the anion. Structure of the obtained mono- and diphosphinates, as well as the quasi-phosphonium salt, was established by NMR spectroscopy and single crystal X-ray diffraction methods.
A Study of Electronic Structure of Diethyldiphenylsilane by X-Ray Emission Spectroscopy and Density Functional Theory Methods
Abstract
X-Ray spectroscopy and DFT study of the electronic structure and chemical bonds of the silicon atom and its surrounding in the molecule of (HC=C)2SiPh2 has been performed. The X-ray emission Si Kβ1 spectrum has been registered and the electronic structure of diethynyldiphenylsilane and C2H2 has been simulated. The valence bands electronic states density distribution for the silicon atom and the carbon atoms of the phenyl and ethynyl groups has been obtained. The theoretical results are in good agreement with the experimental ones, allowing detailed description of the mechanism of the electronic structure formation of the valence bond in (HC≡C)2SiPh2.
Effect of Chemical Composition of Fullerenes on the Structure and Internal Rotation Barrier of Encapsulated Ammonia Borane Molecule
Abstract
Investigation of the structure and conformational properties of ammonia borane molecule in the cavity of C60, C12B24N24, B36N24, C70, B41N29, C80, C14B33N33, and B47N33 fullerenes using the DFT PBE/3ζ method has shown the predominance of the staggered conformation of the encapsulated molecule. The guest molecule has bared a notable negative charge and, as compared to the free molecule of ammonia borane, has a shortened B←N coordination bond. The internal rotation barrier about this bond has depended on the composition of the fullerene shell so that the decrease in the number of carbon atoms due to the replacement with boron-nitrogen fragments has almost always resulted in a notable decrease in the ΔG≠298 value. In this case, the minimal energy of the activation barrier, 1.3–1.8 times lower than that simulated for the free molecule, has been observed for the clusters with the boron-nitrogen-carbon links in the fullerene shell.
Thermochemistry of the Acid-Base Interactions in Aqueous Solutions of Isonicotinic and Picolinic Acids
Abstract
The calorimetric method was employed to measure the heat effects of the interaction of isonicotinic and picolinic acids with HNO3in aqueous solutions over different pH ranges at 298.15 K and ionic strengths of 0.5, 1.0, and 1.5 against potassium nitrate. The heat effects of stepwise dissociation of the acids were determined. The standard thermodynamic characteristics (ΔrH°, ΔrG°, ΔrS°, ΔCp°) of the acid-base reactions in aqueous solutions of isonicotinic and picolinic acids were calculated.
Model of Solvation and Association Processes in Non-Electrolytes Solutions
Abstract
A model of a solution of non-electrolytes has been considered, which is a superposition of equilibrium processes of solvation, homo- and heteroassociation. The chemical potentials and activity coefficients of the components have been calculated for a binary solution considering only symmetric solvation. The model has been verified to calculate the density of binary solutions with high agreement with experimental data.
Synthesis, Structure, and Luminescence Properties of Boron Complex with 4-Bromo-2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenoxide Ligand
Abstract
A boron complex with 4-bromo-2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenoxide ligand has been synthesized, and its photoluminescence properties in solution and in the solid phase have been examined. The structure of the complex has been determined by X-ray analysis. Non-classical intermolecular interaction (halogen bond) between the bromine and fluorine atoms has been detected in the crystal structure of the complex.
Acid—Base Interactions and Complexation of β-Substituted Porphyrazines with Magnesium Salts in Proton-Acceptor Media
Abstract
Analysis of the complexing ability of β-substituted porphyrazines toward magnesium acetate and magnesium acetylacetonate in the systems dimethyl sulfoxide-benzene (chlorobenzene) and nitrogen base-benzene has shown that acid-base interaction is the key factor affecting the complexation of porphyrazines with magnesium salts in proton-acceptor media with different basicities. The mechanism of formation of porphyrazine magnesium complexes and the structure and stability of acid-base complexes of porphyrazines with dimethyl sulfoxide and nitrogen bases in benzene (chlorobenzene) are discussed.
Study of Selected Spectral Properties and Complex Formation with Transition Metals Ions of a New Schiff’s Base Containing Fluorescein and Sulfamide Fragments
Abstract
A new azomethine based on N-aminofluorescein and ortho-tosylaminobenzaldehyde has been synthesized. Structure and properties of the obtained compound have been studied by means of IR, 1H NMR, and electron absorption spectroscopy as well as potentiometry. Using the DFT method, quantum-chemical simulation of electronic absorption spectra has been performed. The complexation of the obtained azomethine in solutions with Cu2+, Ni2+, and Co2+ cations has been studied. Metal chelates (1:2) with Cu(II), Ni(II), Zn(II), and Cd(II) have been isolated. Octahedral structure of the coordination site has been suggested for the obtained metal chelates.
Formation of Oligo-Nuclear Carboxylate Nickel(II) Complexes with Nitrogen-Containing Ligands. Quantum-Chemical Simulation
Abstract
Using the DFT method PBE0/6-31G(d, p) and taking into account the solvent, the formation of bi- and pentahedral Ni(II) complexes with carboxylate and N-containing ligands in the gas phase was studied, and ΔG° of their formation from simple compounds was estimated. The functional role of bridging groups and hydrogen bonds in the formation of polynuclear structures was revealed. A model of self-organization of penta-nuclear coordination compounds [NiII5(O2CR)8L2n(μ-OH)2]0 from binuclear complex [NiII2(O2CR)4Ln(μ-H2O)]0 was proposed, into the structure of which mononuclear NiII cations are embedding and promote proton transfer from bridging aqua ligands.
Double Pseudo-Polymeric Gold(III)-Mercury(II) Complexes [Au(S2CNR2)2]nX [R2 = (CH2)6, (CH2)4O] Containing ([HgCl3]−)n, [HgCl4]2− and [Hg2Cl6]2− Anions: Chemisorption Synthesis, Principles of Supramolecular Self-Assembly, and Thermal Behavior
Abstract
Novel pseudo-polymeric complexes of gold(III)-mercury(II) with cyclic alkylene dithiocarbamate ligands: ([Au{S2CN(CH2)6}2][HgCl3])n, ([Au{S2CN(CH2)6}2]2[HgCl4]·H2O)n, and ([Au{S2CN(CH2)4O}2]2[Hg2Cl6])n have been obtained and structurally characterized. The sophisticated supramolecular structure of the obtained compounds is realized due to secondary non-valent Au⋯S interactions and includes mononuclear and binuclear cations and anions as structural units as well as cationic and anionic polymer chains. The thermal behavior of the obtained complexes has been studied by means of simultaneous thermal analysis. The products of thermal transformations of the complexes are reduced elemental gold and HgCl2.
Mixed-Ligand Europium(III) Complexes with 4-Methylbenzoic Acid
Abstract
Europium(III) complexes with p-methylbenzoic acid and nitrogen- or phosphorus-containing neutral ligand with the compositions [Eu(p-MBA)3·D]2·xH2O and [Eu(p-MBA)3·2H2O]n [where p-MBA is p-methylbenzoate anion and D is 1,10-phenanthroline (phen), 2,2′-bipyridine (bipy), dimethylformamide (dmf), triphenylphosphine oxide (tppo), hexamethylphosphoramide (hmpa) (x = 1), or benzotriazole (bt) (x = 2)] have been synthesized, and their thermal decomposition has been studied.
Synthesis of Highly Transparent SiCxNyOz:H Films via Plasma-Chemical Decomposition of 1,1,3,3,5,5-Hexamethylcyclotrisilazane, Oxygen, and Nitrogen Gas Mixture
Abstract
Synthesis of silicon oxycarbonitride films highly transparent over a wide spectral region (350–2500 nm) has been developed. The films have been deposited during decomposition of 1,1,3,3,5,5-hexamethylcyclotrisilazane in mixtures with oxygen and nitrogen in a high-frequency discharge plasma in the temperature range of 373–973 K. The influence of the synthesis temperature and the oxygen to nitrogen ratio in the initial gas mixtures on chemical and functional properties of SiCxNyOz:H films has been studied using IR and Raman spectroscopy, energy-dispersive spectroscopy, ellipsometry, and spectrophotometry. The composition and selected characteristics of the obtained films have been investigated.
Mechanisms of the Solid-State Synthesis of Ln2SrFe2O7 (Ln = La, Nd, Gd, Dy) Layered Perovskite-Related Phases
Abstract
The formation mechanisms for a series of n = 2 Ruddlesden-Popper phases Ln2SrFe2O7 (Ln = La, Nd, Gd, Dy) in the Ln2O3-SrO-Fe2O3 systems were determined. The solid-state synthesis of Ln2SrFe2O7 (Ln = La, Nd) proceeds by a mechanism involving the stage of formation of LnFeO3 and LnSrFeO4 intermediates with their subsequent interaction to form the target product. In the case of Gd2SrFe2O7 formation, two mechanisms are realized, namely, those going through the GdFeO3 + GdSrFeO4 and Gd2O3 + Gd0.5Sr0.5FeO3-α interaction stages. The limiting stage of the Dy2SrFe2O7 formation is the reaction between Dy2O3 and Dy0.5Sr0.5FeO3-α.
Synthesis, in vitro and in silico Anti-Proliferative Studies of Novel Piperiene-Oxadiazole and Thiadiazole Analogs
Abstract
Piperine is a component of pepper which has earlier been reported as anticancer active compound. This work is emphasized on the design and synthesis of new hybrid piperine analogs by coupling piperine with the amine group of oxadiazoles and thiadiazoles. The new series of twelve piperine analogs was been tested for in vitro anti-proliferative activity using sulforhodamine B (SRB) assay test against MCF-7, PC-3, and HeLa cell lines. Among the twelve synthesised molecules piperine derivative with oxadiazole baring hydroxyl group (3) exhibits the higher activity against MCF-7 cell line than the reference drug Adriamycin and also displays the highest binding energy in the in silico studies. The other analogs are moderately active.
Synthesis of Macrocyclic Ttipeptidopyridine Schiff Base Candidates
Abstract
In the current study, a series of macrocyclic tripeptide Schiff bases 2–6 were synthesized by using macrocyclic tripeptide hydrazide 1 as starting material. Treatment of hydrazide 1 with active carbonyl cycloalkanones gave cycloalkanone hydrazines 2a–2d. Also, condensation of 1 with aromatic and heterocyclic aldehydes, or aromatic and heterocyclic acetyl derivatives afforded the corresponding Schiff base candidates 3a–3e, 4a–4c, 5a–5c, and 6a–6c, respectively.
Pyrazoles and Isoxazoles Based Sulfanilamide and Phenazone as Antimicrobial Agents: Synthesis and Biological Activity
Abstract
New pyrazole and pyridine derivatives have been synthesized from sulfanilamide and phenazone via diazotization and coupling with a wide range of α-CH acids followed by heterocyclization with hydrazine derivative, hydroxylamine and cyanoacetamide. The antimicrobial tests of the products demonstrate high to moderate activity against Gram (−ve) bacteria and the tested fungi. No positive action of the products is observed against Gram (+ve) bacteria.
Synthesis, Crystal Structure, and Antiproliferative Activity of Novel 7-Arylaminopyrazolo[1,5-a]pyrimidine Derivatives Containing the Hydrazone Moiety
Abstract
A series of novel 7-arylaminopyrazolo[1,5-a]pyrimidine derivatives containing the hydrazone moiety has been synthesized by a five-step procedure including cyclization, chlorination, animation, hydrazinolysis, and condensation. Structures of the products have been characterized by IR, 1H NMR and MS spectra, and single-crystal X-ray diffraction. The bioassay results indicate most of the compounds as potentially antiproliferation agents against A549 and HT-29 cell lines. Among those, compounds 6e and 6f exhibit remarkable inhibitory activity against HT-29 cell lines, that are comparable with that of the positive control sorafenib. Preliminary structure-activity relationship is considered.
Letters to the Editor
Synthesis and Biological Activity of β-Aminoketones, Secondary Aminopropanols and Oximes of 2-Aminothiophene Series
Abstract
The reactions of substituted 3-dietliylaminopropan-1-ones hydrochlorides with 2-amino-6-(H, alkyl)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitriles and ethyl 2-amino-6-(H, methyl)-4,5,6,7-tetrariydrobenzo[b]-thiophene-3-carboxylate furnished β-aminoketones of 2-aminothiophene series. The latter were converted into the corresponding secondary aminopropanols and oximes. Antioxidant activity of synthesized compounds and effect on some parameters of the blood coagulation system were investigated.