Interaction of 5-hydroxypyrazolidines with Ch-acid compounds

The interaction of I-acetyl-2 phenyl-5-hydroxypyrazolidine with carbonyl compounds on the surface of acidic aluminum oxide results in the formation of products in which the hydroxyl group has been replaced by the residue of the carbonyl compound. It has been shown that derivatives of ß-dicarbonyl compounds, under the conditions of the reaction, may undergo subsequent conversions in which one of the carbonyl-containing residues is split off.M. V. Lomonosov Moscow State University, Moscow 119899. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 483–489, April, 1994. Original article submitted January 31, 1994.     

Behavior of 2-Phenyl-2,3-dihydro-1H-1,3-phenalenediones in Formylation by Vilsmeier-Haak Procedure

Russian Journal of Organic Chemistry -     

The thermal ionization phase during the plasma formation in TM-1-MH tokamak

The start-up phase of discharge in a TM-1-MH tokamak has been investigated. We present a simple model describing the time evolution of electron density in a time interval where the bulk of electron distribution function is already Maxwellian and thermal ionization of neutral gas dominates. Comparison of the computed results with experimental data proved the validity of this model and allowed us to determine the electron temperature during this period of the discharge. The role of the run-away electron production during the start-up phase is discussed.     

Structure and Reactivity of Bicyclo[2.2.1]hept-2-ene-<Emphasis Type="Italic">endo</Emphasis>-5,<Emphasis Type="Italic">endo</Emphasis>-6-dicarboxylic (endic) Acid Hydrazide

Establishing of the structure of hydrazinolysis product obtained from bicyclo[2.2.1]hept-2-ene-endo-5, endo-6-dicarboxylic (endic) acid was performed by preparation of the compound under alternative conditions followed by comparison of the characteristics and spectral parameters of the resulting substances, and also by quantum-chemical calculations by the density functional method of the chemical shifts in ¹H and ¹³C NMR spectra of different reaction products. The X-ray diffraction analysis of the hydrazide was also carried out. The compound obtained was assigned a structure of N-aminobicyclo[2.2.1] hept-2-ene-endo-5,endo-6-dicarboximide. The products were prepared by its reactions with arylsulfonyl chlorides, benzoyl chlorides, m-tolyl and p-toluene-sulfonyl isocyanates, phenyl isothiocyanate, with o-nitrobenzaldehyde, and oxiranes (1,2-epoxycyclohexane and 2,3-epoxypropylcarbazole). The aromatic sulfonamides, carboxamides, and ureas were epoxidized by performic acid obtained in situ from the formic acid and hydrogen peroxide. Products of [3+2]-cycloaddition of aryl azides to the strained double bond in the N-aminobicyclo[2.2.1] hept-2-ene-endo-5,endo-6-dicarboximide and its derivatives. The structures of compounds obtained were confirmed by their IR, 1H and 13C NMR spectra.     

Features of 3-amino-5-methylisoxazole in heterocyclizations involving pyruvic acids

Chemistry of Heterocyclic Compounds - The chemical properties of 3-amino-5-methylisoxazole in the reactions involving pyruvic acid derivatives are reported. The multicomponent condensation of...     

Origin of Bragg-Coulomb high-Tc superconductivity Green''s function and diagram method for umklapp e-e scattering

The Green's function method and diagram technique for umklapp electron-electron scattering mediated by the screened Coulomb interaction in layered anisotropic conductors are examined. Gor'kov-type equations and their general solution for anomalous and normal temperature Green's functions are derived taking into account umklapp scattering of all orders. Explicit equations for dielectric and superconducting order parameters, including coexistent Bragg and BCS pairing, are found. The possibility of the first-order phase transition to the superconducting state is discussed. The theory elucidates the origin of Bragg-Coulomb high-T_c superconductivity, proposed by the authors.