Oximes as products in the reactions of 5‐substituted 2‐nitrothiophenes with arylacetonitriles

It has been shown that reactions 5‐substituted 2‐nitrothiophenes with arylacetonitriles in the presence of potassium hydroxide in methanol lead to the formation of the new [2‐(hydroxyimino)‐5‐R‐3(2H)‐thienylidene](aryl)acetonitriles. Under proposed reaction conditions, the formation of thieno[2,3‐c]isoxazole was not the case. J. Heterocyclic Chem., (2011).     

Facile and Efficient One-Pot Procedure for Thieno[2,3-e][1,2,3]triazolo[1,5-a]pyrimidines Preparation

Base-catalyzed cycloaddition reactions of heterocyclic azides with activated nitriles were studied. Convenient, efficient, and high-yield synthetic method for thieno[2,3-e][1,2,3]triazolo[1,5-a]pyrimidines preparation from available starting reagents without complicated protocols was elaborated. Such an approach allows creation of broad combinatorial libraries for drug discovery.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Quasi-linearization and stability analysis of some self-dual,dark equations and a new dynamical system†

We describe a class of self-dual dark nonlinear dynamical systems a priori allowing their quasi-linearization, whose integrability can be effectively studied by means of a geometrically based gradient-holonomic approach. A special case of the self-dual dynamical system, parametrically dependent on a functional variable is considered, and the related integrability condition is formulated. Using this integrability scheme, we study a new self-dual, dark nonlinear dynamical system on a smooth functional manifold, which models the interaction of atmospheric magneto-sonic Alfvén plasma waves. We prove that this dynamical system possesses a Lax representation that allows its full direct linearization and compatible Poisson structures. Moreover, for this self-dual nonlinear dynamical system we construct an infinite hierarchy of mutually commuting conservation laws and prove its complete integrability.     

Adsorption of ammonia on graphite oxide/Al13 composites

Graphite oxide/Al₁₃ composites were prepared using graphite oxide and commercial solution of Chlorhydrol^®. Although surfactant was used to disperse of graphene-like layers, they were restacked together upon addition of Al₁₃ Keggin polycations. The crust of inorganic phase was deposited on the outer surface of GO platelets. The resulting materials were used as adsorbents of ammonia in dry or wet conditions either in an as received form or prehumidified for 2 h before the breakthrough test. It was shown that water in the system decreases the amount adsorbed, likely as a result of the competition with ammonia for adsorption centers. The highest and strongest adsorption was found in the dry conditions where interlayer space was partially available and the acidic centers of an inorganic phase played an enhancing role in the retention of ammonia.     

Novel Selected Tandem Transformations of the Amino and Carbonyl/Nitrile Groups in the Gewald Thiophenes

Novel transformations of the amino and carbonyl/nitrile groups in the Gewald thiophenes were studied for thienopyrimidine synthesis. It was found that 2-amino-thiophene-3-carboxamides and ethyl 2-(acetylamino)-4,5,6,7-tetrahydro-1-benzothiophene-3-carbo- xylate did not yield tetrazole derivatives, neither in the reaction with triethyl orthoformate and sodium azide, nor in the reaction with phosphorus oxychloride and sodium azide, correspondingly. On the contrary, derivatives of thieno[2,3-d]pyrimidin-4(3H)-one and thieno[2,3-d][1,3]oxazin-4-one were isolated. New 2-azidothiophenes [2-azido-4,5,6,7-tetra hydro-1-benzothiophene-3-carbonitrile and 2-azido-4,5,6,7-tetrahydro-1-benzothiophen-3-yl(phenyl)methanone] were synthesized and used in anionic domino reactions with activated acetonitriles to yield thieno[3,2-e][1,2,3]triazolo[1,5-a]pyrimidines and/or 2-(5-amino-1H-1,2,3-triazol-1-yl)thiophenes. Finally, a new ring system of thieno[3,2-e]pyrazolo[1,5-a]pyrimidine was synthesized via a domino reaction of ethyl 2-[(2Z)-2-(1-chloro-2-ethoxy-2-oxoethylidene)hydrazino]-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate with activated acetonitriles.     

The crystal structure of Sm4Ni11In20 and its relation to other indium-rich compounds

Polycrystalline Sm₄Ni₁₁In₂₀ was obtained by arc-melting of metal ingots. A subsequent high temperature treatment was used for single crystal growth. The Sm₄Ni₁₁In₂₀ crystal structure (U₄Ni₁₁Ga₂₀ type; C2/m, a = 22.5457(3) Å, b = 4.34929(5) Å, c = 16.5479(2) Å, β = 124.592(2)°, R1 = 0.0358, wR2 = 0.0934) was determined by single crystal synchrotron radiation X-ray diffraction from 2014 independent reflections with I > 2σ(I). Sm₄Ni₁₁In₂₀ extends the R ₄Ni₁₁In₂₀ (R = Y, Gd, Tb, Dy, Ho) series of phases. The R ₄Ni₁₁In₂₀ and RNi₃In₆ (LaNi₃In₆ type; R = La, Ce, Pr, Nd, Eu) series have similar compositions. Their structures share similar fragments; in particular the rare earth atom coordination polyhedra are pentagonal prisms with additional atoms.      

Jessen–Wintner type random variables and fractal properties of their distributions

Formulas are given for the Lebesgue measure and the Hausdorff–Besicovitch dimension of the minimal closed set S_ξ supporting the distribution of the random variable ξ = 2^–k τ_k, where τ_k are independent random variables taking the values 0, 1, 2 with probabilities p _0k , p _1k , p _2k , respectively. A classification of the distributions of the r.v. ξ via the metric‐topological properties of S_ξ is given. Necessary and sufficient conditions for superfractality and anomalous fractality of S_ξ are found. It is also proven that for any real number a ₀ ∈ [0, 1] there exists a distribution of the r.v. ξ such that the Hausdorff–Besicovitch dimension of S_ξ is equal to a ₀. The results are applied to the study of the metric‐topological properties of the convolutions of random variables with independent binary digits, i.e., random variables ξⁱ = , where η_k are independent random variables taking the values 0 and 1. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

On the loss process in a batch arrival queue

In this paper, we investigate the loss process in a finite-buffer queue with batch arrivals and total rejection discipline. In such a model, if the buffer has insufficient capacity to accept all the customers included in an arriving batch, the whole batch is blocked and lost. This scheme is especially useful in performance evaluation of buffering processes in IP (internet protocol) networks. The main result of this paper is a closed-form formula for the joint distribution of the length of the first lost series of batches and the time of the first loss. Moreover, the limiting distribution (as the buffer size grows to infinity) is shown.     

Understanding the tetrazole ring cleavage reaction with hydrazines: Structural determination and mechanistic insight

A distinction in the behaviour of several hydrazines as N-nucleophiles in the recently developed one-pot method for pyrimidine core annulation via 1H-tetrazole ring cleavage was examined. The product structures, 2,3-diamino- or hydrazino derivatives of thieno[3,2-d]pyrimidin-4(3H)-ones, thieno[2,3-d]pyrimidin-4(3H)-ones and [1]benzofuro[3,2-d]pyrimidin-4(3H)-one, were elucidated based on NMR and single crystal X-ray analysis.     

Charge Transfer Salt with Substituted Lindquist Polyoxometalate: Synthesis, Crystal Structure, and Physical Properties of α-(BEDT-TTF)6(VW5O19)⋅DMF⋅2H2O

A new charge transfer salt based on bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) and the vanadium substituted Lindquist anion [VW₅O₁₉]^3– was synthesized and characterized by X-ray and spectroscopic analysis. Monoclinic, C2, F _w =3789.2, a=41.5019(5), b=11.2600(2), c=12.7514(2) Å, =101.877(5)°, Z=2, R=0.060, based on 12095 reflections with I>2(I). The structure consists of alternating organic and inorganic layers. The inorganic layer is generated by [VW₅O₁₉]^3– anions, dimethylformamide (DMF) and water molecules. The organic layer, which is generated by three different BEDT-TTF units, belongs to the -type of packing and consists of trimerized chains parallel to the c direction. The compound is a semi-conductor with _{300 K} =1.1 Scm^–1 and E _a =0.1 eV. Polarized reflectance spectra of single crystals were measured over the spectral range from 650 to 25000 cm^–1. FT-NIR Raman spectra of powdered crystals dispersed in KBr pellets were also recorded. Vibrational and electronic features are discussed.