<Emphasis Type="Italic">N</Emphasis>-arylsulfanyl-<Emphasis Type="Italic">N</Emphasis>-arylsulfonyl(acyl)-<Emphasis Type="Italic">N</Emphasis>′-phenylthiourea sodium salts

Reactions of N-arylsulfonyl(acyl)arenesulfenamide sodium salts with phenyl isothiocyanate afforded N-arylsulfanyl-N-arylsulfonyl(acyl)-N-phenylthioura sodium salts which were found to increase thermal stability of finely dispersed poly(vinyl chloride).Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, pp. 1532–1535.Original Russian Text Copyright © 2004 by Koval, Oleinik.     

<Emphasis Type="Italic">N</Emphasis>′-tetrazolylmethoxyl derivatives of <Emphasis Type="Italic">N</Emphasis>-methyldiazene <Emphasis Type="Italic">N</Emphasis>-oxides

A preparation method was developed for previously unknown tetrazole derivatives containing in the 1, 2, and/or 5 positions of the tetrazole ring N-methyldiazene-N-oxide-N′-oxymethyl groups.     

Structure of Iron(III)-containing complexes based on the azomethine — 4,4′-dodecyloxy-benzoyloxybenzoyl-4-salicylidene-<Emphasis Type="Italic">N</Emphasis>′-Ethyl-<Emphasis Type="Italic">N</Emphasis>-ethylenediamine molecule

Iron(III)-containing complexes with an asymmetric tridentate azomethine 4,4′-dodecyloxybenzoyloxybenzoyl-4-salicylidene-N′-ethyl-N-ethylenediamine ligand with NO₃⁻, PF₆⁻, Cl⁻, and BF₄⁻ counterions are synthesized. The presence of the complexation ion is confirmed by the far FTIR spectra. The structure of the compounds is determined by the matrix-assisted laser desorption/ionizationtime of flight (MALDI-ToF) method. The results of mass-spectrometric studies are consistent with the elemental analysis data. The complexation of iron salts with the asymmetric tridentate ligand is found to yield compounds of the 1:1 composition with octahedral packing of iron in the complex.     

Preparation and crystal structure of bis(triethylene glycol-<Emphasis Type="Italic">O</Emphasis>,<Emphasis Type="Italic">O</Emphasis>′,<Emphasis Type="Italic">O</Emphasis>′’,<Emphasis Type="Italic">O</Emphasis>‴)manganese(II) dibromide

A new complex, bis(triethylene glycol-O,O′,O′’,O?)manganese(II) dibromide [Mn(TEG)₂]²⁺·2Br^?, was prepared. Its structure was studied by single crystal X-ray diffraction. The complex cation [Mn(TEG)₂]²⁺ is of the host-guest type with two TEG ligands (podands) as hosts. Both TEG ligands are disordered and tetradentate, with all the four oxygen atoms of each ligand participating in the coordination. The Mn²⁺ cation has coordination number 8, and its coordination polyhedron is a distorted bisdisphenoid (trigonal dodecahedron). The geometric parameters (bond lengths, bond and torsion angles) of the complex were determined relatively accurately. In the crystal structure, the ions form infinite thick layers by interionic hydrogen bonds O-H···Br^?.     

The Merrifield–Simmons index in (<Emphasis Type="Italic">n</Emphasis>, <Emphasis Type="Italic">n</Emphasis> + 1)-graphs

A (n, n + 1)-graph G is a connected simple graph with n vertices and n + 1 edges. In this paper, we determine the upper bound for the Merrifield–Simmons index in (n, n + 1)–graphs in terms of the order n, and characterize the (n, n + 1)–graph with the largest Merrifield–Simmons index.     

New heteroscorpionate lanthanide complexes for ring-opening polymerisation of <Emphasis Type="Italic">ε</Emphasis>-caprolactone and <Emphasis Type="Italic">rac</Emphasis>-lactide

Yttrium and lanthanum amido-complexes with bis(pyrazol-1-yl)acetates in their coordination spheres were studied as the catalysts in ε-caprolactone and lactide ring-opening polymerisation. A high molecular mass poly(ε-caprolactone) (PCL) was obtained in almost quantitative yield under mild conditions. rac-Lactide polymerisations were less efficient and required quite harsh experimental conditions to obtain atactic PLA samples with moderate yields. The average chain-length of PCL was dependent upon the choice of the metal centre and the presence of substituents on the pyrazole rings of the ancillary ligand. The ground-state geometries of the complexes and the first stages of ε-caprolactone polymerisation were computationally modelled by means of DFT calculations.     

Synthesis, <Emphasis Type="Italic">β</Emphasis>-<Emphasis Type="Italic">Glucuronidase</Emphasis> Inhibition,and Molecular Docking Studies of 1,2,4-Triazole Hydrazones

A series of 1,2,4-triazole hydrazones 1–25 has been synthesized and characterized using different spectroscopic techniques including FT-IR, ¹H-NMR, and ESI MS spectrometry. The synthetic derivatives were evaluated for their β-glucuronidase enzyme inhibition properties. Among them, 17 compounds demonstrated potential inhibitory activity towards β-glucuronidase with IC₅₀ values ranging between 2.50 and 53.70 µM. Compounds 1 having IC₅₀?=?2.50?±?0.01 µM was found to be the most active compound of the series and showed remarkable activity and found to be far more potent than the standard d-saccharic acid 1,4-lactone (IC₅₀?=?48.4?±?1.25 µM). Furthermore, the possible binding interaction of active compounds was explored by in silico studies. These compounds can be used for anti-diabetic drug development process.     

<Emphasis Type="Italic">iso</Emphasis>-<Emphasis Type="Italic">α</Emphasis>-Cyclopiazonic acid,a new natural product isolated from the marine-derived fungus <Emphasis Type="Italic">Aspergillus flavus</Emphasis> C-F-3

A new natural product, iso-α-cyclopiazonic acid (1), together with its isomer α-cyclopiazonic acid (2); three mycotoxins: aflatoxin B₁ (AFB₁) (3), aflatoxin Q₁ (AFQ₁) (4), and O-methylsterigmatocystin (OMST) (5); two diketopiperazine alkaloids: ditryptophenaline (6) and 3-[(1H-indol-3-yl)methyl]-6-benzylpiperazine-2,5-dione (7), were isolated from the marine-derived fungus Aspergillus flavus. Their structures were determined by analysis of spectroscopic data. The cytotoxicities of compounds 1 and 2 were studied using HL-60, MOLT-4, A-549, and BEL-7402 cell lines.     

Features of phosphorylation of Per-6-<Emphasis Type="Italic">O</Emphasis>-(<Emphasis Type="Italic">tert</Emphasis>-butyldimethylsilyl)-β-cyclodextrin with a phosphorous diamidoester

Phosphorylation of secondary hydroxy groups in per-6-O-(tert-butyldimethylsilyl)-β-cyclodextrin with a phosphorous diamidoester is found to proceed, unlike phosphorylation of free β-cyclodextrin, at an elevated temperature and is accompanied by substantial desilylation.     

Synthesis and characterization of some <Emphasis Type="Italic">o</Emphasis>,<Emphasis Type="Italic">o</Emphasis>′-dihydroxyazo dyes and their metal complexes

The synthesis and characterization of azo dyes containing o,o′-dihydroxy groups and their azo-metal(II) [Cu, Co, Ni, Zn] chelates by ¹H N.M.R., IR, AAS, UV–VIS, magnetic susceptibility and thin-layer chromatography techniques are reported. The stochiometry of the azo-metal chelates was determined by the spectroscopic titration method to be 1:2 (ML₂). The synthesized azo dyes and azo-metal chelate dyes were applied on wool fabric. Fastness to light and washing were measured.     

First example of the synthesis of <Emphasis Type="Italic">S</Emphasis>,<Emphasis Type="Italic">O</Emphasis>-macroheterocycle based on 2(5<Emphasis Type="Italic">H</Emphasis>)-furanone and 2,2´-oxydiethanethiol

A base-catalyzed reaction of 3,4-dichloro-5-methoxy- and 3,4-dichloro-5-ethoxy-2(5H)-furanones with 2,2´-oxydiethanethiol gave thiols and bis-thioethers of 2(5H)-furanone series. A new S,O-macroheterocyclic compound containing a 18-membered oxathiamacrocycle and two 2(5H)-furanone fragments was synthesized based on the thiols in an aqueous solution of potassium hydroxide, which was characterized by X-ray diffraction.     

Determination of the <Emphasis Type="Italic">R</Emphasis> ⇄ <Emphasis Type="Italic">S</Emphasis> enantiomerization barrier in 5,6-dihydrobenzoimidazo[1,2-<Emphasis Type="Italic">c</Emphasis>]quinazolines

Chiral imidazoquinazolines undergoing thermally induced reversible R ⇄ S enantiomerization have been synthesized by the interaction of 2-(o-aminophenyl)benzimidazoles with aldehydes and ketones. The benzimidazole fragment has been used for the first time as an indicator group in temperature-dependent ¹H NMR spectra for determining the energy barrier of this rearrangement. The effects of nearby substituents on the kinetic and activation parameters, and on the recyclization mechanism have been investigated.     

Synthesis,structural characterization,electrochemical studies and DFT calculations on nickel(II) complexes of <Emphasis Type="Italic">N</Emphasis>-picolinoyl-<Emphasis Type="Italic">N</Emphasis>′-benzothioylhydrazide and 5-(pyridine-4-yl)-2H-1,2,4-triazole-3-thione

Two Ni(II) complexes, [Ni(pbth)₂] and [Ni(ptt)₂(en)₂] {Hpbth = N-picolinoyl-N′-benzothioylhydrazide, Hptt = 5-(pyridine-4-yl)-2H-1,2,4-triazole-3-thione} have been synthesized and characterized by physico-chemical and spectroscopic methods. [Ni(pbth)₂] contains a pair of N-picolinoyl-N′-benzothioylhydrazide ligands coordinated via their thione sulfur, pyridyl nitrogen and hydrazinic nitrogen atoms, forming two C₂N₂Ni and two CSN₂Ni five-membered chelate rings. The intermediate compound 1-isonicotinoyl-3-thiosemicarbazide is converted to 5-(pyridine-4-yl)-2H-1,2,4-triazole-3-thione in the presence of ethanolic NaOH, giving the complex [Ni(ptt)₂(en)₂] in which the ptt ligands coordinate through their triazole ring nitrogen atoms, while four more nitrogens from two ethylenediamine ligands complete the octahedral structure. The crystal structures of the complexes involve various types of intermolecular extended hydrogen bonds, forming supramolecular frameworks. Cyclic voltammetry studies of both complexes show quasi-reversible redox behavior. Density Functional Theory electronic structure calculations corroborate our experimental findings.     

Three New <Emphasis Type="Italic">in situ</Emphasis> Syntheses of <Emphasis Type="Italic">N</Emphasis>-Acyl-α-triphenylphosphonioglycinates

Summary. N-Acyl--hydroxyglycinates were transformed into N-acyl--triphenylphosphonioglycinates by (i) phosphorylation with Ph ₃PBr₂ in the presence of Et ₃N or (ii) in reaction with DCC and Ph ₃P·HBF₄ in the presence of catalytic amounts of Ph ₃P as well as (iii) by a new kind of Mitsunobu reaction with Ph ₃P·HBF₄ as a nucleophile conjugated acid. The N-acyl--triphenylphosphonioglycinates can be effectively used without isolation for a nucleophilic displacement of the triphenylphosphonium group to obtain corresponding -substituted -amino acid derivatives.     

X-ray and computational structural study of neutral <Emphasis Type="Italic">bis</Emphasis>(<Emphasis Type="Italic">N,N,N</Emphasis>′,<Emphasis Type="Italic">N</Emphasis>′-tetramethylthiophosphoramidoyl)-methylamine

The structure of bis(N,N,N′,N′-tetramethylthiophosphoramidoyl)-methylamine 1 has been determined by single-crystal X-ray diffraction. The compound 1 crystallizes in the monoclinic system, with a space group P2₁/c, a = 11.836(2) Å, b = 11.659(2) Å, c = 12.796(5) Å and β = 95.28(3)°, V = 1758.3(5) Å³ and Z = 4. The X-ray crystallographic data have been assessed by semi-empirical and ab-initio density functional theory and by Hartree–Fock molecular orbital methods. A comparative study of the results of the different methods is given.     

Unusual transformation of (1<Emphasis Type="Italic">R</Emphasis>,1′<Emphasis Type="Italic">S</Emphasis>,2<Emphasis Type="Italic">S</Emphasis>)-1-(3-diisopropylamino-3-oxopropyl)-2-(1-hydroxyethyl)cyclopropane in the course of the cyclopropylcarbinyl rearrangement

The cyclopropylcarbinyl rearrangement of (1R,1′ S,2S)-1-(3-diisopropylamino-3-oxo-propyl)-2-(1-hydroxyethyl)cyclopropane and the participation of the amide moiety in the intramolecular process smoothly affords the (2′ E,5S)- N,N-diisopropyl-N-[5-(but-2′-enyl)tetra-hydrofuran-2-yridene ] ammonium salt.     

Synthesis of ethyl (±)-(13,15-dideoxy)-16-methyl-9-oxoprosta-13(<Emphasis Type="Italic">E,Z</Emphasis>),15(<Emphasis Type="Italic">E</Emphasis>)-dienoate

The condensation of ethyl 7-(2-oxo-5-formulcyclopentyl)heptanoate by Wittig reaction with the ylide prepared from [(2E)-3-methylhept-2-en-1-yl]triphenylphosphonium bromide afforded ethyl (±)-(13,15-dideoxy)-16-methyl-9-oxoprosta-13(E,Z),15(E)-dienoate as a mixture of two isomers, 2:1.     

Synthesis and characteristics of <Emphasis Type="Italic">N</Emphasis>-(glyoxyldioxime)-<Emphasis Type="Italic">N</Emphasis>′-(2-hydroxybenzylidene)-1,4-diaminonaphthalene and its metal complexes

A new vic-dioxime, N-(glyoxyldioxime)-N′-(2-hydroxybenzylidene)-1,4-diaminonaphthalene, was synthesized proceeding from naphthalene. Its complexes of nickel, copper and cobalt were prepared. The vicdioxime and its complexes were charecterized by FT-IR, UV, ¹H NMR, mass spectrometry, elemental analysis, DTA/TG analysis techniques and conductometric measurements. Published in Russian in Zhurnal Obshchei Khimii, 2008, Vol. 78, No. 5, pp. 797–802. The text was submitted by authors in English.