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991.
The anhydride and dimethyl ester of 4, 5-(1-benzyl-1, 2, 3-triazoline)-3, 6-endohexahydrophthalic acid, having a triazoline ring with an exo-cis configuration, are synthesized by reaction of benzyl azide with the furan-maleic anhydride adduct. Opening of the triazoline ring under the action of hydrochloric and acetic acids takes place with the separation of nitrogen and formation of the chloro and acetoxy derivatives, respectively, unaccompanied by a Wagner-Meerwein type of rearrangement.Part XXIV, see [1].  相似文献   
992.
Dimethyl zinc reacts with diethyl amine, piperidine and morpholine forming definite 1:2- or 1:1-complexes. The weaker basic secondary amines pyrroline, pyrazolidine and imidazoline cause the evolution of methane and the formation of the corresponding zinc amides. In this way zinc pyrrolide, zinc pyrazolide and zinc imidazolide were obtained in form of pure substances.  相似文献   
993.
The properties and reactivities of 4-hydroxy- and 2,4-dihydroxy-5-(β-hydroxyethyl)pyrimidines and of the products of their transformations have been studied. 4-Chloro- and 2,4-dichloro-5-(β-chloroethyl)pyrimidines have been obtained. A number of 4-alkyl(aryl)amino-5-(β-chloroethyl)pyrimidines have been synthesized, and they have been converted into derivatives of 5,6-dihydropyrrolo[2,3-d]pyrimidine.  相似文献   
994.
The three-body classical trajectory Monte-Carlo (CTMC) method is used to investigate positron-argon atom collisions. The total ionization cross sections are presented along with singly and doubly differential cross sections. The existence of the cusp-like peak in the triply differential electron and positron spectra at positron impact is predicted.  相似文献   
995.
Syntheses of 5-isopropyl-1,3-cyclohexadiene and syn-5-isopropyl-2,3-dioxabicyclo[2.2.2]octane, by routes that would allow completely diastereoselective introduction of deuterium labels, are described. The reaction of the isopropyl cyclohexadiene with singlet oxygen is shown to give an endoperoxide that is derived by preferential attack on the more sterically hindered face of the diene. A possible mechanistic explanation of this result is that the attack from the less hindered face leads to "ene" reaction rather than endoperoxide formation. However, this mechanism would require that the "ene" reaction and cycloaddition proceed via a common intermediate-presumably a perepoxide.  相似文献   
996.
New environmental applications of radiation technology developed in the laboratory of the author are considered. They include the electron-beam and coagulation purification of molasses slops from a distillery that produces ethanol by fermentation of plant raw materials, the removal of petroleum products (diesel fuel, motor oil, and residual fuel oil) from water by -irradiation, and the electron-beam treatment of multicomponent natural gas mixtures of lower hydrocarbons for the purpose of condensation.  相似文献   
997.
Complexes of CuHg(NCS)4, CuHg(NCS)2 (NCSe)2 and CuHg(NCSe)4 with tetrahydrofuran, dioxane, pyridine, 2-aminopyridine, nicotinamide, bipyridine and phenanthroline have been prepared and comparative studies made. Bipyridine and phenanthroline form cationic—anionic [CuL3]2+ [Hg(SCN)4]2? (L = bipy, phen) complexes with CuHg(NCS)4 and dinuclear bridged complexes with CuHg(NCSe)4 and CuHg(NCS)2 (NCSe)2. For other ligands the nature of the complexes is binuclear or polynuclear. The comparative stability of the -XCN- bridge (X = S, Se) is CuHg(NCSe)4 > CuHg(NCS)2 (NCSe)2 > CuHg(NCS)4.  相似文献   
998.
The present work studies the changes in polymer structure and the mechanism of the decomposition of polytetrafluoroethylene resin (PTFE) exposed to high energy radiation (electron beam). Spectroscopic and kinetic observations are used to interpret the degradation process. For the first time the decomposition of PTFE has been carried out on a preparative scale and new results obtained by analysing the degradation products. The radiation-induced degradation of PTFE is accompanied by thermal degradation under certain irradiation conditions. This is due to an increase in temperature of the polymer caused by retardation of highly accelerated electrons (heat accumulation effect).The kinetics are discussed in terms of the reactions and recombination of radicals produced by high-energy radiation both in the polymer melt and the polymer surface. These are related to the overall rate of decomposition.The primary radicals formed by decomposition of PTFE in an inert atmosphere (N2, Ar) react to produce perfluorinated alkanes and alkenes. In the presence of reactive gases the decomposition fragments originated will react rapidly; e.g. if oxygen is present in the reactive area the radicals form perflourinated peroxyl and oxyl radicals which finally stabilize themselves by CC-scission to perfluorocarbon acid fluorides and carbonyldifluorides.  相似文献   
999.
Summary The number average micellar molecular weights,M n , were determined with the application of membrane osmometry, for various nonionic and a cationic surfactant, in aqueous solutions. These results show that these micelles are monodisperse, as also reported by other investigators. The dependence ofM n on temperature was also studied. It was found that both the nonionic and the cationic micelles showed an abrupt change in logM versus temperature plots. In the case of nonionics, the abrupt change was observed at approximately 30 °C lower than the cloud-point.Presented at the 25th Colloid-Meeting in Munich, October 13–15, 1971.  相似文献   
1000.
delta1-Tetrahydrocannabinol, delta6-tetrahydrocannabinol, cannabinol, cannabidiol and several of their monooxygenated derivatives have been separated from each other by a combination of liquid, thin-layer and gas chromatography. Retention volumes (on Sephadex LH-20), Rf values and retention times can be recorded, and may provide guidance in the separation and identification of these known cannabinoids.  相似文献   
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