Oxidation of 2,6-disubstituted phenols as a route to 3,5,3′,5′-tetrasubstituted diphenoquinones and 4,4′-dihydroxydiphenyls

Conclusions Oxidation of 2,6-disubstituted phenols by atmospheric oxygen in the presence of a cuprammonium complex gave 3,3,5,5-tetraalkyldiphenoquinones which were converted to the corresponding 4,4-dihydroxydiphenyls.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1808–1810, August, 1987.     

Determination of Amine-Containing Drugs in Micellar Matrices by Spectrophotometry Using Box–Behnken Plans

Journal of Analytical Chemistry - The results of using the “response surface” methodology and the Box–Behnken design in the spectrophotometric determination of medicinal...     

Peroxysolvates of carbamide and sodium carbonate in the nucleophilic decomposition of paraoxon

The nucleophilic decomposition of paraoxon (4-nitrophenyl ester of diethylphosphoric acid) by the HOO⁻ anion generated from peroxysolvates of sodium carbamide and carbonate in aqueous, micellar, microemulsion, and water–ethanol media was studied. Feasibility was demonstrated for the use of solid sources of hydrogen peroxide in decontaminating nucleophilic systems.     

Oxidation of methyl phenyl sulfide by carbamide peroxide in the presence of activators

The oxidation of methyl phenyl sulfide by carbamide peroxide in water and water–ethanol mixtures proceeds at the same rates as oxidation by hydrogen peroxide. In the presence of ammonium bicarbonate, the reaction proceeds through a pathway including HCO₄^- as a more active oxidizing agent than H₂O₂.     

Some more on the finite automata

Some new problems of the theory of the finite automata are considered. Applying the finite automata in various tasks of the formal languages theory is observed. Special proof of Kleene’s theorem is obtained. This proof is used for the defining the star-height of the finite automaton. The properties of the last object are considered. The star-height of the finite automaton is used for reformulating the star-height problem of regular expressions for finite automata. The method of the reduction of the star-height problem to the task of making special finite automaton is obtained. This reformulating can help to solve the star-height problem by new way.     

Simulation of spin reorientation in cubic ferromagnets with defects

Nucleation processes in spin-reorientation phase transitions in real magnets are studied theoretically. The magnetization distribution corresponding to zero-degree domain wall forms the basis of the model representation of nuclei of the new phase, which are pinned at detects. As a result of numerical implementation of the corresponding variational problem for a finite-thickness plate, stable states of such magnetic inhomogeneities are determined and it is shown that their structure and properties are mainly controlled by parameters of a defect and the Q factor of the sample. The dependences obtained in this way make it possible to describe the behavior of new-phase nuclei in the vicinity of the spin-reorientation phase transition, which is in qualitative agreement with experimental data.     

Kinetic Model of the PTC Aminolysis of 4-Nitrophenyl Acetate with Solid Potassium Glycinate

A mechanism of phase-transfer catalysis in a solid/liquid system was proposed during akinetic investigation of the aminolysis of 4-nitrophenyl acetate with solid potassium glycinate in chlorobenzene in the presence of 18-crown-6. The quantitative parameters were determined for all the stages of the catalytic cycle, including the distribution of the reagents between the phases and the chemical reactions that occur.     

Synthesis of <Emphasis Type="Italic">N</Emphasis>-Tosylates of 4-Methoxy-1,2,3,4-tetrahydrocarbazole and 2-(6-Methoxy-1-cycloalken-1-yl)anilines

The reaction of N-tosylates of 2-(1-cycloalken-1-yl)anilines and 2,3,9a,9-tetrahydro-1H-carbazole with methanol in the presence of CuBr₂ proceeds with high regioselectivity leading to the corresponding tosylates of 2-(6-methoxy-1-cycloalken-1-yl)anilines and 4-methoxy-1,2,3,4-tetrahydrocarbazole. The latter as well as N-mesyl-1,2,3,4-tetrahydrocarbazole showed moderate cytotoxic activity with respect to HEK293 cell line.