STUDY ON THE SYNTHESIS OF A NEW TYPE OF PHOSPHORUS HETEROCYCLIC COMPOUNDS-PYRAZOLO[3, 4-d]-1, 3, 2-DIAZAPHOSPHORIN-6-ONE

1-substituted-5-benzoylamino-4-pyrazolecarboxamides(2)were prepared by the reaction of 1-substituted pyrazolo[3, 4-d]-oxazinone(1)with amines in benzene.The compound 2 was refluxed with excess LiAlH₄ in a mixture of THF and ether, one of the two carbamoyl groups in the molecule 2 was reduced selectively.As the results, 1-substituted-5-benzylamino-4-pyrazolecarboxamides (3) were obtained.Compounds 3reacted with Cl₂PPh-X, or P(NET₂)3, producing the title compounds(4).The conditions of the reactions were studied.     

Reactions of 4-(o-carboranyl)pyrylium salts with nucleophilic agents. Synthesis of nitrogen heterocycles with an o-carboranyl substituent

Nitrogen heterocycles, viz., pyridines, pyridinium salts, diazepine, and pyrazoles, with an o-carboranyl substituent were obtained by reaction of 4-(o-carboranyl)-pyrylium perchlorates with nitrogen-containig nucleophilic agents, viz., ammonia, primary amines, hydrazine, and phenylhydrazine. Opening of the pyrylium ring without involvement of the carborane ring occurs under the influence of bases.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 454–458, April, 1981.     

Electrochemical synthesis of carbonyl- and phosphoryl-containing methano[60]fullerenes

The combined electrochemical reduction of fullerene C₆₀ in the presence of p-bromo-benzoyldibromomethane or bis(diisopropoxyphosphoryl)dibromomethane at a brass electrode in a mixed solvent o-dichlorobenzene-MeCN (3:1 v/v)/0.05 M Bu₄NBF₄ at room temperature affords 61-(p-bromobenzoyl)methano[60]fullerene or 61,61-bis(diisopropoxyphosphoryl)methano[60]fullerene, respectively, in 50% yields.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2681–2685, December, 2004.     

Complex dynamics in a periodically perturbed electro-chemical system

Dynamical response of a passivation model subjected to parametric periodic and stochastic perturbations is studied numerically. In response to weak periodic modulation, the system exhibits a rich variety of resonance behavior and induced dynamics, including periodically induced oscillation, birhythmicity, switching between two bistable states, selection of one of the bistable states, mixed-mode and chaotic oscillations. These phenomena are discussed in terms of the stability of saddle focus and an incomplete homoclinic connection. Our numerical results are relevant for a wide class of electro-chemical oscillatory systems, where the re-injection of unstable trajectory on the neighborhood of a saddle focus is a typical feature in the phase space.     

Synthesis and configuration of diastereomeric 2,4-, 2,5-, and 2,6-piperidinedicarboxylic acids and their dimethyl esters

The reduction in an acidic medium over a platinum catalysts of 2,4-, 2,5-, and 2.6-pyridinedicarboxylic acids gave cis-2,4-, -2,5-, and -2,6-piperidinedicarboxylic acids, heating of which in an alkaline medium led to thermodynamically equilibrium mixtures of diastereomers. Individual trans-2,5-piperidinecarboxylic acid was isolated. The configurations of the 2,4-, 2,5-, and 2,6-piperidinedicarboxylic acids and their methyl esters were established by means of the PMR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 367–371, March, 1985.     

Three-dimensional structure of 3-acylindoles

On the basis of a comparison of the experimental dipole moments with the calculated values, as well as data from the UV, IR, and PMR spectra, it is shown that 3-acylindoles exist in the form of equilibrium mixtures of the planar S-cis and S-trans conformers with preponderance of the latter.DeceasedTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1647–1652, December, 1982.     

The thermodynamic parameters of formation of ions in the interaction of alkylaluminum with electron donors

The thermodynamic parameters of formation of ions in the system AlMe₃ + electron donor (D) in the presence and absence of water microimpurities were determined. The structure of these ions was studied and their concentration in nonpolar media was estimated for the example of D = pyridine. The conclusion was drawn from the results of calculations that the participation of water resulted in a substantial increase in the concentration of ions.