Selenyl chloride as an active chlorinating agent

Conclusions A new method was discovered for the preparation of selenyl chloride and its chlorinating properties in reactions with isoprene and citronellyl acetate were studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2615–2617, November, 1986.     

Hydrolysis of acetylsalicylic acid under the conditions of electrolysis

The hydrolysis of acetylsalicylic acid in the anolyte under the conditions of electrolysis was studied.     

Ruthenium(Ⅲ) chloride as an efficient catalyst for the synthesis of perimidine derivatives under mild conditions

Various biologically important perimidine derivatives have been synthesized efficiently from various ketones and naphthalene1,8-diamine by using a catalytic amount of RuC13 (1 mol%). This method is a very simple and high yielding reaction for the synthesis of perimidine derivatives.     

Effect of hydrodynamic electrolysis conditions on the kinetics of cathodic processes in chromium(III) sulfate electrolytes

The effect of stirring on the kinetics of electrode processes in a chromium-plating electrolyte based on chromium(III) sulfate is studied. The electrolyte, in which thick (up to 120 μm) hard chromium coatings can be obtained, is stirred with a magnetic stirrer. Hydrodynamic conditions in the system are calibrated in a modeling solution containing the same components as the electrolyte (with the exception of chromium sulfate which is replaced by an equivalent amount of aluminum sulfate), by the reaction of discharge of hydronium ions. It is shown that reactions of discharge of hydronium ions and incomplete reduction of trivalent chromium ions occur in a diffusion mode. The Cr(III)-Cr(II) system is classified with quasi-reversible redox electrodes and is described by the known equation for diffusion kinetics. The electrodeposition of metallic chromium occurs in the mixed kinetics mode     

Formation of dibromo-, bromochloro-, and dichlorocarbenes in the cathodic electrolysis of tetrabromomethane in the presence of chloride ions

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, p. 2183, September, 1988.     

Synthesis of asymmetrical thioethers with sulfinamides as the sulfenylation agent under metal-free conditions

Using sulfinamides as a new reagent for preparation of asymmetrical thioethers has been developed under metal-free conditions. The reactions proceeded smoothly without the use of stinky thiophenol, highly toxic sulfonyl chloride or oxidant. Such a simple, efficient transformation provides an attractive approach to various diaryl sulfides in good to excellent yields.     

Mechanism of the platinum nanoparticles formation under conditions of nonstationary electrolysis

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Plasma-induced cathodic discharge electrolysis to form various metal/alloy nanoparticles

Nanoparticles of various elements such as Si, Al, and Zr were formed by plasma-induced cathodic discharge electrolysis in molten chloride electrolyte under a 1 atm Ar atmosphere. Al and Si nanoparticles with 100 nm diameters were obtained from an LiCl-KCl-CsCl melt at 300°C. Zr nanoparticles with diameters less than 50 nm were obtained from an LiCl-KCl at 450°C. Then with a newly designed and constructed “rotating disk anode type electrolytic cell”, Ti nanoparticles with diameters less than 20 nm were obtained. Finally, to find more appropriate condition for obtaining finer and more uniform nanoparticles, the effects of the pulse conditions of the applied current and the rotating velocity of a disk anode on size and morphology among the obtained nanoparticles were investigated by choosing Ni nanoparticle formation as an example. The results showed that quick removal of the formed fine nanoparticles from the melt surface, where the discharge column is standing, is the most important factor to obtain smaller and more uniform nanoparticles.     

Synthesis of 2,4,5-triaryl and 1,2,4,5-tetraaryl imidazoles using silica chloride as an efficient and recyclable catalyst under solvent-free conditions

An efficient solvent-free synthesis of various 2,4,5-triaryl imidazoles and 1,2,4,5-tetraaryl imidazoles has been developed using silica chloride as a heterogeneous catalyst. The present methodology offers several advantages, such as excellent yields, shorter reaction times, economic availability, and reusability of catalyst.     

Elemental sulfur as a stabilizing agent for vinyl chloride polymers

The possibility of stabilization of some vinyl chloride polymers with elemental sulfur in their thermal and thermal oxidative degradation was studied.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 11, 2004, pp. 1877–1879.Original Russian Text Copyright © 2004 by Kolesov, R. M. Akhmetkhanov, Nagumanova, Kabalnova, R. R. Akhmetkhanov, Zaikov.     

Reactions of some arenes and pyrazoles in MeCN under conditions of undivided-cell electrolysis

As exemplified for the first time by pyrazole and its 4-nitro and 3,5-dimethyl derivatives, N-arylation of pyrazoles can be performed under conditions of undivided-cell amperostatic electrolysis (Pt electrodes, MeCN) of systems containing the pyrazolate anion and (or) pyrazole, arene (benzene, 1,4-dimethoxybenzene, or xylene), and a supporting electrolyte. In the case of electrolysis involving 1,4-dimethoxybenzene as arene, N-arylation followed simultaneously three routes to form an ortho-substitution product (1,4-dimethoxy-2-(pyrazol-1-yl)benzene), an ipso-substitution product (4-methoxy-1-(pyrazol-1-yl)benzene), and an ipso-bisaddition product (1,4-dimethoxy-1,4-di(pyrazol-1-yl)cyclohexa-2,5-diene) in a total current yield of up to 50%. The acid-base properties of the pyrazoles under study affect the ratio of the N-arylation products and govern the required composition of the starting reaction mixture. In the case of a stronger base, such as 3,5-dimethylpyrazole, N-arylation with 1,4-dimethoxybenzene occurred even in the pyrazole—arene—tetraalkylammonium perchlorate system, whereas N-arylation of 4-nitropyrazole (a weaker base) proceeded only in the presence of the pyrazolate anion or another base, viz., sym-collidine. Oxidation of arene to the radical cation is the key anodic reaction. Not only the pyrazolate anion, but also highly basic pyrazole or a solvate complex of weakly basic pyrazole with collidine can serve as a nucleophilic partner in subsequent transformations of these radical cations.     

Silica-supported antimony(III) chloride as an efficient heterogeneous catalyst for the synthesis of aminopropenones and 3-aminopropenoates under solvent-free conditions

A convenient and efficient procedure has been developed for the synthesis of 3-aminoprop-2-en-1-ones and 3-aminoprop-2-enoates catalyzed by silica-supported antimony(III) chloride at room temperature under solvent-free conditions. The reaction takes a short time and ensures good to excellent yields of the products. Both aromatic and aliphatic amines and various 1,3-dicarbonyl compounds, including β-ketoesters and β-diketones, can be involved. Published in Russian in Zhurnal Organicheskoi Khimii, 2009, Vol. 45, No. 1, pp. 25–28. The text was submitted by the authors in English.     

Polystyryl-supported TBD as an efficient and reusable catalyst under solvent-free conditions

Polystyryl supported-TBD (PSTBD) is an efficient and reusable heterogeneous basic catalyst under solvent-free conditions for a variety of organic transformations such as 1,2-epoxide ring-opening, aldol-type condensation and Michael addition.     

Dorzolamide hydro­chloride: an anti­glaucoma agent

Dorzolamide hydro­chloride [systematic name: (4S)‐trans‐4‐ethyl­ammonio‐6‐methyl‐5,6‐dihydro‐4H‐thieno[2,3‐b]thio­pyran‐2‐sulfonamide 7,7‐dioxide chloride], C₁₀H₁₇N₂O₄S₂⁺·Cl⁻, belongs to a class of drugs called carbonic anhydrase inhibitors. The ethyl­ammonio side chain is in an extended conformation and is protonated at the N atom, which is hydrogen bonded to the Cl⁻ anion. The dihedral angle between the planes of the thio­phene ring and the sulfonamide group is 80.7 (1)°. A comparison is made with the dorzolamide bound in human carbonic anhydrase in the solid state. Hydrogen bonding is mediated by Cl⁻ anions, resulting in indirect connectivity between the mol­ecules.     

Investigations into the mechanism of action of nitrobenzene as a mild dehydrogenating agent under acid-catalysed conditions

Protonated nitrobenzene can be used to dehydrogenate a range of hydrocarbons, which already possess at least one double bond. Kinetic and spectroscopic results, together with known electrode potentials, yield approximate limits within which protonated nitrobenzenes can be expected to effect dehydrogenation of hydroaromatic compounds. A high yielding synthesis of benzo[j]fluoranthene is described.     

Reactivity of p-nitrostyrene oxide as an alkylating agent. A kinetic approach to biomimetic conditions

The alkylating potential of p-nitrostyrene oxide (pNSO)--a compound used as a substrate to study the activity of epoxide hydrolases as well as in polymer production and in the pharmaceutical industry--was investigated kinetically. The molecule 4-(p-nitrobenzyl)pyridine (NBP), as a model nucleophile for DNA bases, was used as an alkylation substrate. In order to gain insight into the effect of the hydrolysis of pNSO, as well as the hydrolysis of the NBP-pNSO adduct on the pNSO alkylating efficiency, these two competing reactions were studied in parallel with the main NBP-alkylation reaction. The following conclusions were drawn: (i) pNSO reacts through an S(N)2 mechanism, with NBP to form an adduct, pNSO-NBP (AD). The rate equation for the adduct formation is: r = d[AD]/dt = k(alk)[NBP][pNSO]-k(hyd)(AD) [AD] (k(alk), and k(hyd)(AD) being the alkylation rate constant and the NBP-pNSO adduct hydrolysis rate constant, respectively); (ii) the alkylating capacity of pNSO, defined as the fraction of initial alkylating agent that forms the adduct, is similar to that of mutagenic agents as effective as β-propiolactone. The instability of the pNSO-NBP adduct formed could be invoked to explain the lower mutagenicity shown by pNSO; (iii) the different stabilities of the α and β-adducts formed between NBP and styrene oxides show that the alkylating capacity f = k(alk)[NBP]/(k(alk)[NBP] + k(hyd)) (k(hyd) being the pNSO hydrolysis rate constant) as well as the alkylating effectiveness, AL = f/k(hyd)(AD), are useful tools for correlating the chemical reactivity and mutagenicity of styrene oxides; (iv) a pNSO-guanosine adduct was detected.