Synthesis of hydrocarbons and alcohols from CO and H2 in the presence of CO-Rh catalysts

Catalysts of 4.5% Co- 0.1% Rh- 5:10% Cu/TiO ₂ display high activity in the synthesis from CO and H₂ of a mixture of hydrocarbons and alcohols at 250–300°C and pressures of 0.1–6.0 MPa; these catalysts are more selective than traditional Co catalysts with respect to alcohol formation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1707–1709, August, 1990.     

Nitration of furan derivatives with acetyl nitrate

The mixture of products formed in the nitration of methyl furan-2-carboxylate in acetic anhydride was separated by means of thin-layer and column chromatography. It was found that products of cis and trans addition of acetyl nitrate to the furan ring — methyl 5-nitro-2-ace-toxy-2,5-dihydrofuran-2-carboxylate and 5-nitro-4-acetoxy-4,5-dihydrofuran-2-carboxylate — and methyl 5-nitrofuran-2-carboxylate are formed in the nitration.     

Features of complexing of molecular NMR relaxation probes with cellulose acetates in solutions

The method of active and inert NMR relaxation probes can be used for determining the degree of substitution of cellulose acetates. The formation of hydrogen bonds between the hydroxyl and acetate groups of cellulose acetate is more probable than between the hydroxyl groups, which results in relative large shielding of the free OH groups in the polymer in samples with high degrees of substitution.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1761–1765, August, 1989.We would like to thank N. I. Naimark for providing the samples of the cellulose acetates.     

Autoxidative transformations of 2-substituted 3-alkyl-4-hydroxy-1-oxo-1, 2-dihydroisoquinolines

A method for the preparation of 2-substituted 3-alkyl-4-hydroxy-1-oxo-1, 2-dihydroisoquinolines is described. It is shown that 2, 3-dialkyl-substituted derivatives readily undergo autoxidation and dealkylation to give N-methylphthalonimide and 3-hydroperoxy and 3-hydroxy-2, 3-dialkyl-1, 4-dioxo-1,2,3,4-tetrahydroisoquinolines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 789–792, June, 1978.     

Bromination of 2,6-dimethyl-3,5-dimethoxycarbonyl-4-(2′-difluoromethoxyphenyl)-1,4-dihydropyridine (foridone)

The action of mild brominating agents (pyridinium bromide-perbromide, dioxan dibromide N-bromosuccinimide, and N-bromoacetamide) on 2,6-dimethyl-3,5-dimethoxy-carbonyl-4-(2-difluoromethoxyphenyl)-1,4-dihydropyridine (Foridone) has been studied. Depending on reaction conditions, furo-, difuro-, and dibromomethyl-1,4-dihydropyridines are obtained together with certain oxidized forms.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 948–952, July, 1989.     

Effective account of 2p–2h excitations in molecular calculations by the equation-of-motion method

The excitation energies and oscillator strengths of transitions in the helium atom (as a test system) and carbon dioxide and ethylene molecules are calculated by a modified equation-of-motion method with effective account of the most important polarization effects, including the 2p−2h (two particles-two holes) interactions, in the quasiparticle approximation of the density functional. Two different types of the effective potential of the partile-hole polarization interaction are used. The accuracy of the calculations is sensitive to the type of the potential. It is shown that the account of the polarization corrections for the 2p−2h effects is of fundamental importance since it contributes up to 30% to the values of the excitation energies and oscillator strengths. Odessa Institute of Hydrometeorology. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 4, pp. 615–622, July–August, 1995. Translated by I. Izvekova     

Nucleophilic addition of difunctional reagents to 2,3-dichlorobenzo[b]thiophene 1,1-dioxide

The nucleophilic reactions of 2,3-dichlorobenzo[b]thiophene 1,1-dioxide with - and -glycols, -diamines, and -amino alcohols proceed with cleavage of hydrogen chloride to give the previously unknown 3-monosubstituted derivatives of 2-chlorobenzo[b]thiophene 1,1-dioxide. The second functional group (the hydroxyl group in amino alcohols) does not enter into the reaction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1602–1604, December, 1972.     

Conformational properties of the 2′- and 3′-hydroxy groups of 5′-O-trityluridine

The results of a study of the temperature dependence of the SSCCs of the hydroxyl protons in the PMR spectra of 5′-O-trityluridine indicate the existence of an intramolecular bond between the 2-keto oxygen of the base and the 2′-hydroxyl in deuterochloroform. Under these conditions, stabilization of the 3′-endo (N) conformation of the ribose ring is observed. The existence of the influence of the temperature on the population of the 3′-hydroxyl rotamers shows the formation of a hydrogen bond between OH-3′ and O-2′. In polar solvents free rotation of the hydroxy groups is observed.     

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Chemistry of Heterocyclic Compounds -     

Heterylimidazoles IV. Homolytic dissociation of hexaaryldimidazolyls and their heterocyclic analogs

The rate constants and activation energies for homolytic dissociation of 2,2-di[ ()-naphthyl]-, 2,2-diquinolinyl-, and 2,2-di(9-acridinyl)-4,4,5,5-tetraphenyldiimidazolyls in toluene in the presence of,-diphenyl--picrylhydrazine were determined. The degrees of dissociation of the diimidazolyls were found. The effect of substituents on the stability of imidazolyl radicals is discussed.See [1] for communication III.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1536–1539, November, 1974.