Role of Supercritical Water and Pyrite in Transformations of Propylene

The effect of supercritical water and pyrite on the transformations of propylene upon the uniform heating (1.5 K/min) of reagents to 718 K is studied. The products are analyzed by IR and ¹H NMR spectroscopy, mass-spectrometry and gas chromatography/mass-spectrometry. It is established based on the temperature dependences of the pressure of reagents that the addition of pyrite in the absence of water gives rise to a decrease in the starting temperature of propylene oligomerization. In the absence of pyrite, the addition of water suppresses propylene oligomerization. A synergetic effect of supercritical water and pyrite on the degree of conversion of propylene is revealed. It is shown that hydrogen sulfide, thiols, and methyl-derivatives of thiophene are formed in the presence of pyrite, as well as the yield of aromatic and polyaromatic hydrocarbons increases. The mechanisms of the observed processes are discussed.     

Reaction of 2-polyfluoroacylcyclohexanones with semicarbazides

2-Polyfluoroacylcyclohexanones react with semicarbazide and thiosemicarbazide to give 2-(thio)carbamoyl-3-hydroxy-3-polyfluoroalkyl-3,3a,4,5,6,7-hexahydro-2H-indazoles, one of which was studied by X-ray diffraction. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 361–365, February, 1999.     

One-pot synthesis of 1,3-bis(cytisinyl)propan-2-ol

Russian Journal of Organic Chemistry -     

Acyl pyruvates as synthons in the Biginelli reaction

Chlorotrimethylsilane-promoted Biginelli-type reaction of ethyl 2,4-dioxo-4-phenylbutanoate, benzaldehyde, and various (thio)ureas is explored. The outcome of the reaction depends on the structure of the (thio)urea used and is strongly affected by the acceptor electronic properties of the COOEt substituent in the molecule of the starting β-dicarbonyl compound. The di- and tetrahydropyrimidine derivatives obtained possess two functional groups with orthogonal reactivity, and thus represent promising building blocks for drug discovery.     

Reagents for specific modification of biopolymers

Direct nucleophilic substitution of primary and secondary amines for hydrogen in quaternary phenazinium salts containing an additional positive charge in the aliphatic part of the molecule was carried out. The substitution proceeds successively in positions 2 and 7, which allows selective introduction of different substituents into the heterocycle. For Part 9, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1157–1160, June, 1999.     

Measurement of fluctuation-induced particle fluxes in the shadow of the diaphragm of the FT-2 tokamak

Movable multielectrode probes are used in an experimental study of fluctuations in particle density and electric field, their spectral and correlation characteristics, and the poloidal-radial distributions of fluctuation-induced drift fluxes in the shadow of the diaphragm of the FT-2 tokamak. The spatial regions in which these fluxes are particularly intensive at different stages of the discharge are determined. The part played by fluctuation-induced fluxes in the peripheral radial particle transport is estimated and found to be substantial. Zh. Tekh. Fiz. 67, 48–54 (April 1997)