Phase equilibria in the Cu–Cu<Subscript>2</Subscript>Se–As system

Phase equilibria in the Cu–Cu₂Se–As were investigated by differential thermal analysis and X-ray powder diffraction analysis. Informative plots describing this system were constructed, viz., the polythermal sections Cu_0.667Se_0.333–As, Cu_0.667Se_0.333–Cu_0.735As_0.265, and Cu_0.8Se_0.2–As, the isothermal section of the phase diagram at 300 K, and the projection of the liquidus surface. The obtained results differ from the published data in length of fields of primary crystallization of phases and in coordinates of a number of invariant equilibrium points.     

Theoretical and experimental study of the transformation of 2-pyridone-5-amide into nitrile

Molecular and crystal structures of 2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carboxamide (1), 2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carbonitrile (2), and 2-chloro-4,6-dimethylniсotinonitrile (3), which are the products of sequential transformations, are studied by means of single crystal diffraction. The procedure for synthesizing each compound is described. All of the compounds are characterized using IR and ¹H NMR spectra. Possible reaction pathways are simulated using the density functional theory (DFT).     

Greener approach: Ionic liquid [Et3NH][HSO4]-catalyzed multicomponent synthesis of 4-arylidene-2-phenyl-5(4H)oxazolones under solvent-free condition

We have developed simple, greener, safer multicomponent synthesis series of 4-arylidene-2-phenyl-5(4H) oxazolones 4(a-r) catalyzed by Bronsted acid ionic liquid as triethylammonium hydrogen sulfate [Et₃NH][HSO₄] and catalytic amount of acetic anhydride and sodium acetate with excellent yields (90–99%). The protocol offers economical, environmentally benign, solvent-free conditions, and recycle–reuse of the catalyst and easily available starting as benzoyl chloride 1, amino acid 2 and a variety of aldehydes 3. The cyclization followed by condensation of benzoyl chloride, amino acid, and a variety of aldehydes catalyzed by ILs [Et₃NH][HSO₄] and catalytic amount of acetic anhydride and sodium acetate. The final products were confirmed by their characterization data such as FTIR, ¹H-NMR, ¹³C-NMR, Mass, high-resolution mass spectra and were compared with its reported method.     

Sequential reactions from catalytic hydroformylation toward the synthesis of amino compounds

Different families of new amino compounds were efficiently synthesized, through optimized sequential processes, involving rhodium catalyzed hydroformylation as the key step. The selection of appropriate hydroformylation catalytic systems and reaction conditions allowed obtaining aldehydes derived from several n-alkyl olefins, cholest-4-ene and 3-vinyl-1H-indole, which were subsequently transformed, in one-pot, in to α-amino acids via hydroformylation/Strecker reaction, and in to tertiary amines via hydroaminomethylation, with excellent yields.     

Two crystalline polymorphic forms of α-(<Emphasis Type="Italic">N</Emphasis>-benzoxazolin-2-one)acetic acid

Two crystalline polymorphic forms of α-(N-benzoxazolin-2-one)acetic acid (BAA) are prepared by changing the temperature of its crystallization from solution in ethanol. Crystallographic data of the α-form are determined: a = 12.7769(17) Å, b = 8.2574(9) Å, c = 16.7390(19) Å, β = 105.087(13)°, space group C2/c, V = 1705.2(4) ų, and Z = 8, while those of β form are a = 5.2854(4) Å, b = 5.9880(4) Å, c = 13.4509(5) Å, β = 94.666(4)°, space group P2₁, V = 424.30(4) ų, and Z = 2. It is found that BAA molecules of the α form combine into infinite one-dimensional chains arranged along axis b by means of O?H···O and C?H···O hydrogen bonds, and these chains are crosslinked via C?H···O hydrogen bonds to form a threedimensional structure. The β form has another system of hydrogen bonds, one of which is bifurcated (O4···O2, O4···O3), and the π–π-interactions between the benzoxazolinone fragments of BAA molecules combined into a chain also arranged along axis b are observed. Calorimetric analysis shows that the polymorphic transition from the α form to the β form occurs at 129°C.     

On water direct arylation of imidazo[1,2-a]pyridines with aryl halides

A simple, mild, and ecofriendly protocol for a palladium-catalysed direct arylation of imidazo[1,2-a]pyridines with aryl halides on water is reported. This protocol does not require any ligand and tolerate variety of functional groups on both the coupling partners. The simple base KOH is highly efficient in this transformation.

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Molecular and crystal structure of a mixed-ligand cadmium complex with <Emphasis Type="Italic">p</Emphasis>-hydroxybenzoic acid and monoethanolamine

Single crystals of a mixed-ligand cadmium complex of the composition Cd(PHBA)₂(MEA) ₂ are grown from the solution of Cd(CH₃OO)₂, p-hydroxybenzoic acid (PHBA) and monoethanolamine (MEA) in aqueous ethanol. The crystallographic data are as follows: a = 11.6400(2) Å, b = 10.1363(1) Å, c = 16.6296(2) Å, β = 93.937(1)°, space group I2/a, V = 1957.44(5) ų, Z = 4. In the complex molecule located on the twofold axis, ligands of both types are bidentately bound to the cadmium ion having the coordination number 8. In the crystal structure, two H bonds of the O–H???O type combine complex molecules into layers parallel to the ab plane.     

Mathematical simulation of the formation of liquid products from catalytic cracking gases over a zeolite-containing catalyst modified with Group VI and VIII metals

The kinetics of the formation of liquid products from catalytic cracking gases over a zeolite-containing catalyst in a flow reactor in the temperature range from 260 to 420°C at GHSV = 30–264 h^–1 and an on-stream time of 5–25 s has been investigated. A kinetic model for the process proceeding according to a likely scheme is proposed. The rate constants and activation energies of certain reactions involved in the process have been determined. A mathematical model of the process taking into account the mass and heat balances, as well as hydrodynamic conditions, has been developed. The concentration and temperature fields and the pressure over the catalyst bed height have been calculated. The target product yield on has been plotted as a function of the on-stream time.     

Y-type zeolites for the catalytic oxidative degradation of organic azo dyes in wastewater

Cobalt- and iron-containing catalysts active in the oxidation of organic dyes with hydrogen peroxide have been prepared from granular synthetic NaY and HY zeolites without a binder by ion exchange followed by heat treatment at 350–500°C. It has been demonstrated by X-ray photoelectron spectroscopy that cobalt and iron in these catalysts are in the form of Co²⁺ and Fe³⁺ ions on the support surface. The FeHY and CoNaY catalysts are most effective and stable in the oxidation of the anionic dye carmoisine in weakly acidic and alkaline media.     

Anti-inflammatory chromone alkaloids and glycoside from Dysoxylum binectariferum

Herein we report isolation of a new chromone alkaloid chrotacumine K (12) from fruits and a chromone glycoside schumaniofioside A (13) from leaves of Dysoxylum binectariferum Hook f. Schumaniofioside A is reported for the first time from Meliaceae family. Other known alkaloids isolated include rohitukine (1) and chrotacumine E (6). The structure of new alkaloid 12 was elucidated on the basis of extensive 1D and 2D NMR analysis, synthesis and chemical hydrolysis. Chemically, chrotacumine K (12) is a 3′-O-acetyl rohitukine which on chemical or enzymatic hydrolysis produces rohitukine. The new alkaloid 12 is also present in seeds and stem-barks of this plant. The glycoside schumaniofioside A (13) is present only in leaves, and in abundance (～1% w/w of dried leaves). The isolated compounds and extracts were evaluated for in vitro effect on the proinflammatory cytokines (TNF-α and IL-6) in human monocytic THP-1 cells. The alkaloid 12 displayed potent inhibition (57%) of TNF-α at 0.3 µM, and was non-toxic to THP-1 cells up to 40 µM, indicating its excellent therapeutic window. Furthermore, a nitrobenzoyl ester analog 15e showed better inhibition of IL-6 than parent natural product chrotacumine K.