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Inert Solvent (inert + solvent)
Selected AbstractsRoom Temperature Borylation of Arenes and Heteroarenes Using Stoichiometric Amounts of Pinacolborane Catalyzed by Iridium Complexes in an Inert Solvent.CHEMINFORM, Issue 12 2004Tatsuo Ishiyama Abstract For Abstract see ChemInform Abstract in Full Text. [source] The essential oil co-distillation by superheated vapour of organic solvents from aromatic plantsFLAVOUR AND FRAGRANCE JOURNAL, Issue 5 2001Josip Masteli Abstract A method of essential oil co-distillation by superheated vapour of solvents was developed and the apparatus was presented. As suitable solvents, pentane and ether (inert solvent with low boiling point) were used. The method was tested on sage, Salvia officinalis L., as an aromatic plant. The essential oil of this plant was also isolated by hydrodistillation as a standard method. The isolated volatiles obtained by two methods were analysed using gas chromatography (GC) and gas chromatography,mass spectrometry (GC,MS). The obtained results were compared. This method of distillation enables safe isolation of monoterpene and sesquiterpene compounds, as well as hydrodistillation. Copyright © 2001 John Wiley & Sons, Ltd. [source] Kinetics and mechanism of the radical copolymerization of 4-vinyl pyridine with methyl acrylate initiated by p -acetylbenzylidene triphenylarsonium ylideJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2009S. P. Tiwari Abstract The free-radical copolymerization of 4-vinyl pyridine (4-VP) with methyl acrylate (MA) initiated by p -acetylbenzylidene triphenylarsonium ylide at 60 ± 0.1°C with dioxane as an inert solvent yielded random copolymers. The kinetic equation was Rp , [Ylide]0.83[4-VP]0.33 [MA]0.40 (where Rp is the rate of polymerization); in other words, the system followed nonideal kinetics. The values of the energy of activation and kp2/kt (where kp is the rate constant of propagation and kt is the rate constant of termination) were 23.21 kJ/mol and 1.212 × 10,5 mol L,1 s,1, respectively. The reactivity ratios calculated with the Kelen,Tüdos method were 0.14 ± 0.0075 for 4-VP and 0.56 ± 0.0078 for MA. The copolymers were characterized with Fourier transform infrared, proton nuclear magnetic resonance, differential scanning calorimetry, and electron spin resonance methods. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Mechanistic studies of intramolecular CH insertion reaction of arylnitrenes: isotope effect, configurational purity and radical clock studiesJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 1 2005Shigeru Murata Abstract In order to reveal the mechanism of the intramolecular CH insertion of arylnitrenes, three experiments were carried out: measurement of isotope effects, determination of the extent of configurational retention and radical clock studies. Irradiation of the deuterium-substituted azide 4 - d in an inert solvent exclusively afforded the indolines 5 - h and 5 - d, in which the kinetic isotope effect kH/kD on the intramolecular CH insertion of the nitrene was evaluated as 12.6,14.7 at room temperature. A chiral chromatographic analysis of the indoline 11 obtained from the optically active azide (S)- 6 revealed that the enantiomeric purity of the starting azide was almost completely lost during the intramolecular CH insertion of the photolytically generated nitrene (enantiomeric excess <10%). The thermolysis of the azide 7 at 180°C mainly gave a mixture of the cyclopropyl ring-opened products 20,22, together with the intramolecular CH insertion product with an intact cyclopropyl ring 19. On the basis of these observations, we concluded that the intramolecular CH insertion of the nitrene proceeds primarily by the hydrogen abstraction,recombination mechanism. We propose, however, a small contribution of the concerted mechanism to the intramolecular CH insertion, based on the solvent dependence of the isotope effect and the extent of the configurational retention. Copyright © 2004 John Wiley & Sons, Ltd. [source] Studies on the Autoxidation of Aryl AlkenesCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 10 2006W. Ya. Abstract Autoxidation activity of substituted styrenes (aryl alkenes) and their product formation were studied in the temperature range of 65,125,°C using cumene or chlorobenzene as solvent. It was observed that higher reaction temperatures, inert solvent, electron donating substituents, and bulky sterical groups at ,-, ortho- and para- positions promoted radical formation of epoxides and led to C=C oxidative cleavage. In contrast, electron accepting substituents and using cumene as the solvent favored the formation of oligomeric peroxides. The relative activity of all investigated styrenes could be correlated to the linear free energy (LFE) relation and the ionization potential. For ,-substituted styrenes and ring substituted ,-methylstyrenes LFE correlation for the reactivity of aryl alkenes and formation of epoxides was found to depend on the polar and steric factors. A general pathway for product formation by autoxidation of aryl alkenes has been proposed. [source] Selective Hydrogenation of 4-Substituted Phenols to the Cyclohexanone Analogues , Catalyst Optimization and KineticsCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 5 2003M. Wydra 4-position substituted cyclohexanones are of great importance as key intermediates for the synthesis of liquid-crystal materials. Unsubstituted cyclohexanone can be manufactured by the selective hydrogenation of phenol. Industrial processes exist, in which phenol is hydrogenated by a heterogeneous catalyst in the vapor or liquid phase melt with high selectivity leading to high amounts of cyclohexanone. However, very little kinetic data exists to date for the selective hydrogenation of phenol and the cresols in an inert solvent. The aim of this work is to optimize the selective liquid-phase hydrogenation of 4-(4,-trans-n-propylcyclohexyl)-phenol. [source] | ||||||||||