Novel syntheses of some new 3,4-dihydrospiro{benzimidazo[1,2-<Emphasis Type="Italic">a</Emphasis>]pyridine-3,3′-indolin}-2′-one derivatives

Abstract  2-Methylbenzimidazole 1 reacted with 3-dicyanomethylidine-1-ethyl-2-oxoindoline 2 in ethyl acetate to afford 1-amino-2-cyano-3,4-dihydro-1′-ethylspiro{benzimidazo[1,2-a]pyridine-3,3′-indolin}-2′-one 6, which was used as a key intermediate in the synthesis of fused spiropolyheterocyclic derivatives of benzimidazopyridopyrimidine and/or benzimidazonaphthyridine nucleus incorporating an indoline moiety. Graphical abstract        

Thermal stability and crystallization kinetics of ternary Se–Te–Sb semiconducting glassy alloys

This paper presents the results of kinematical studies of glass transition and crystallization in glassy Se_85?x Te₁₅Sb _x (x = 2, 4, 6 and 8) using differential scanning calorimetry (DSC). From the dependence on heating rates of, the glass transition temperatures (T _g), and temperature of crystallization (T _p) the activation energy for glass transition (E _g) and the activation energy for crystallization (E _c) are calculated and their composition dependence can be discussed in term of the average coordination number and cohesive energy. The thermal stability of Se_85?x Te₁₅Sb _x was evaluated in terms of criterion ΔT = T _c ? T _g and kinetic criteria K(T _g) and K(T _p). By analyzing the crystallization results, the crystallization mechanism is characterized. Two (two- and three-dimensional growth) mechanisms are working simultaneously during the amorphous–crystalline transformation of the Se₈₃Te₁₅Sb₃ alloy while only one (three-dimensional growth) mechanism is responsible for the crystallization process of the chalcogenides Se_85?x Te₁₅Sb _x (x = 4, 6 and 8) glass. The phases at which the alloy crystallizes after the thermal process have been identified by X-ray diffraction.     

Synthesis,in-vitro cytotoxicity of 4<Emphasis Type="Italic">H</Emphasis>-benzo[<Emphasis Type="Italic">h</Emphasis>]chromene derivatives and structure—activity relationships of 4-aryl group and 3-, 7-positions

A series of 2-amino-4H-benzo[h]chromene and 2,7-diamino-4H-benzo[h]chromene derivatives were prepared as potential cytotoxic agents. The structures of the synthesised compounds were established on the basis of spectral data. The in-vitro cytotoxic activity of the synthesised compounds against the cell lines MCF-7, HCT-116 and HepG-2 was investigated in comparison with vinblastine and colchicine, using an MTT colorimetric assay. The structure-activity relationship of 4H-benzo[h]chromenes with modification at the 3-, 4- and 7-positions was explored. The results of the anti-tumour evaluation revealed that compounds VIIIc, VIId, VIIb, VIIe, VIIIg and VIIIc, VIId, VIIb, VIIe, VIIIg, VIIc, VIIIe, Vf, IIIa inhibited the growth of MCF-7 in comparison with vinblastine and colchicine, while VIIb, VIId, VIIe, IIIa, VIIa, VIIIc, VIIc, IIId, IIIg, IIIf, IIIb, IIIh, VIIIb, VIIIa, VIIIe, IIIc, Vg, IIIe, VIIIg, Vf, IIIf inhibited the growth of HCT-116 in comparison with colchicine. In addition, compounds VIIe, IIIg, IIIa, VIIc and VIIe, IIIg, IIIa, VIIc, VIIb, VIIa, VIIIf, VIIIe inhibited the growth of HepG-2 in comparison with vinblastine and colchicine, respectively.     

Differential evolution framework for big data optimization

During the last two decades, dealing with big data problems has become a major issue for many industries. Although, in recent years, differential evolution has been successful in solving many complex optimization problems, there has been research gaps on using it to solve big data problems. As a real-time big data problem may not be known in advance, determining the appropriate differential evolution operators and parameters to use is a combinatorial optimization problem. Therefore, in this paper, a general differential evolution framework is proposed, in which the most suitable differential evolution algorithm for a problem on hand is adaptively configured. A local search is also employed to increase the exploitation capability of the proposed algorithm. The algorithm is tested on the 2015 big data optimization competition problems (six single objective problems and six multi-objective problems). The results show the superiority of the proposed algorithm to several state-of-the-art algorithms.     

Synthesis and spectroscopic properties of some new N,N'-disubstituted thiorueas of potential biological interest

Thirty-six new N,N'-disubstituted thioureas have been synthesized by the reaction of phenyl-, p-fluorophenyl- and benzoylisothiocyanates with various substituted anilines, aminopyridines and 4-aminoquinolines. The uv, ir and nmr spectral data are presented and discussed.     

Dihydrofurocoumarin and dihydrofurodihydropyrid-2-one derivatives via palladium catalysed cascades involving aryl/heteroaryl/vinyl iodides and allene followed by acid catalysed cyclisation

Mono 3-(2′-arylallyl) derivatives of 4-hydroxycoumarin 1a,b, 4-hydroxy-6-methyl-pyran-2-one (3) and 6-hydroxy-1,4-dimethyl-1,2-dihydropyrid-2-one-3-carbonitrile (4) are produced in 3-component cascades involving aryl/heteroaryl/vinyl iodides and allene (1 atm) using Pd(PPh₃)₄/Cs₂CO₃/MeCN/80 °C or Pd₂(dba)₃/tris(2-furyl)phosphine/K₂CO₃/DMF/80 °C as the catalyst system. 4-Hydroxy-2-quinolone (2) afforded a mixture of mono- and bis-allylation products under these conditions. Mono C-allylation products 5a-e and 15a-e undergo facile acid catalysed cyclisation to afford dihydrofurocoumarins 11a-e and dihydrofurodihydropyrid-2-ones 16a-e in good overall yield.     

Aluminium-doped LiFePO4 single crystals. Part II. Ionic conductivity, diffusivity and defect model

We report on lithium ion conductivity and diffusivity along major crystallographic directions of Al-doped LiFePO4 single crystals. Impedance spectroscopy as well as galvanostatic polarization measurements have been carried out on the electronically blocking symmetric cell LiAl/LiI/LiFe(Al)PO4/LiI/LiAl. Neither ionic conductivity nor lithium diffusivity show anisotropy in the bc planes within the experimental error, but much lower values in the a-direction. Similar features were observed earlier by us for the pure single-crystal and the Si-doped single crystal. On Al-doping the ionic conductivity has increased while the electronic conductivity has decreased compared to undoped LiFePO4. Not only this donor doping effect but also the temperature dependence of ionic conductivity and of lithium-diffusivity are successfully interpreted in terms of lithium vacancies, holes and associates in the framework of a detailed defect chemical analysis. Ion-electron as well as ion-ion associates play a significant role in this system.