Alkylation of 2-ammopyridine

Alkylation of 2-aminopyridine with cyclohexanol or isopropanol in sulfuric acid gives yields of up to 70% of 2-alkylaminopyridines.     

A dynamic NMR study of Z,E-isomerization in solutions of indolyl-substituted α-nitroacrylates

Fast Z, E-isomerization of α-nitro-β-indolylacrylates in polar solvents has been studied by dynamic ¹H NMR spectroscopy. With indolylnitroacrylates having no substituents at the ring nitrogen atom, isomerization proceeds via intermediate formation of a mesomeric anion and ionization of the N? –H bond as the rate determining step. For methyl-substituted indolylnitroacrylates, no general isomerization mechanism can be suggested, and isomerization pathways depend on the structures of isomerizing species.     

Nucleophilic addition to the phenoxazonium cation

At the instant of its formation of oxidation of phenoxazine with ferric chloride, the phenoxazonium cation adds arenesulfinate and nitrite ions to give 3-arylsulfonyl- and 3-nitrophenoxazines, respectively. It is shown that the introduction of a second sulfonyl group proceeds more slowly and gives 3,7-di(arylsulfonyl)phenoxazines in low yields. The PMR spectra of the synthesized compounds are examined in comparison with 3-substituted phenothiazines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 616–618, May, 1977.     

Catalytic properties of Ni/WS2 samples in thiophene hydrogenolysis

The interaction of diallylnickel with WS₂ produces catalysts whose activity is 10–50 times higher than that of the parent sulfide. The atomic catalytic activity referred to supported nickel is independent of the catalyst type and the sulfur removed in temperature programmed reduction.

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, WS₂ , 10–50 . , , .

     

Mesomorphic and Dielectric Properties of Supramolecular 3,5-Diamino-1-dodecyl-1,2,4-triazole

The formation of a thermotropic smectic phase in 3,5-diamino-1-dodecyl-1,2,4-triazole was revealed by polarizing microscopy and DSC. Depending on heating and cooling conditions, transitions between different types of layered packings occur, which was evidenced by dielectric measurements. Quantum-chemical simulation established that the mesomorphism of 1,2,4-triazole derivatives is associated with the formation of supramolecules with a higher polarizability anisotropy. The calculation results confirmed the possibility of lateral hydrogen bonding which favors layered smectic packing.

     

Synthesis and cytotoxicity of oxindoles dispiro derivatives with thiohydantoin and adamantane fragments

Abstract

An effective and highly regio- and diastereoselective one-pot synthesis of two types of dispiro heterocyclic systems (2-thioxodispiro[imidazolidine-4,3′-pyrrolidine-2′,3″-indoline]-2″,5-diones and 2-thioxodispiro[imidazolidine-4,3′-pyrrolidine-4′,3″-indoline]-2″,5-diones) comprising pyrrolidinyl-oxindole, thiohydantoin and adamantane moieties has been developed based on a 1,3-dipolar cycloaddition of azomethine ylides, generated from isatin and sarcosine or formaldehyde and sarcosine, to adamantane-containing electron-deficient alkenes. Several molecules have demonstrated a considerable cytotoxicity against A549, HEK293T, MCF7 and VA13 cancer cell lines. The possible mechanism of anticancer activity of the synthesized compounds based on literature data may be the inhibition of p53/MDM2 interaction; however, we did not observe significant p53 activation using a reporter construction in A549 cell line in the relevant concentration range.     

Synthesis and properties of fuel cell anodes based on (La0.5 + x Sr0.5 − x )1 − y Mn0.5Ti0.5O3 − δ (x = 0–0.25, y = 0–0.03)

Results are presented of studying electrochemical properties of perovskite-like solid solutions (La_{0.5 + x} Sr_{0.5 ? x} )_{1 ? y} Mn_0.5Ti_0.5O_{3 ? δ} (x = 0–0.25, y = 0–0.03) synthesized using the citrate technique and studied as oxide anodic materials for solid oxide fuel cells (SOFC). X-ray diffraction (XRD) analysis is used to establish that the materials are stable in a wide range of oxygen chemical potential, stable in the presence of 5 ppm H₂S in the range of intermediate temperatures, and also chemically compatible with the solid electrolyte of La_0.8Sr_0.2Ga_0.8Mg_0.15Co_0.05O_{3 ? δ} (LSGMC). It is shown that transition to a reducing atmosphere results in a decrease in electron conductivity that produced a significant effect on the electrochemical activity of porous electrodes. Model cells of planar SOFC on a supporting solid-electrolyte membrane (LSGMC) with anodes based on (La_0.6Sr_0.4)_0.97Mn_0.5Ti_0.5O_{3 ? δ} and (La_0.75Sr_0.25)_0.97Mn_0.5Ti_0.5O_{3 ? δ} and a cathode of Sm_0.5Sr_0.5CoO_{3 ? δ} are manufactured and tested using the voltammetry technique.     

Quantum-Chemical Study of the Structure of N-Substituted p-Quinonimines and Their Reactions with Hydrogen Halides

Quantum-chemical calculations and X-ray diffraction data for a series of N-substituted p-quinon-imines showed that the PM3 method is the most suitable for determination of geometric parameters of these compounds. Moreover, it can be used to predict the site of addition of chlorine and bromine in the hydrohalogenation reaction.