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991.
L. M. Pevzner 《Russian Journal of General Chemistry》2006,76(4):621-625
2-(1-Chloroethyl) and 2-(1-chloro-2-methylpropyl)furans react with sodium diethyl phosphite to give two products, 2-(1-diethoxyphosphorylmethyl)furan and 2-alkyl-5-(diethoxyphosphoryloxy)furan. The fraction of the latter product increases with increasing size of the alkyl radical. 2-Methyl substitution in the substrate completely suppresses phosphate formation. 2-(1-Chloroethyl)-5-(2-methylpropyl)furan under the action of sodium diethyl phosphite eliminates hydrogen chloride to give the corresponding alkene. 相似文献
992.
A survey of recent calculations involving the mixing of Rydberg and valence states in the spectra of molecular systems is undertaken. It is pointed out that when such states undergo curve crossings with one another, minimal energy splittings of 1.0–2.0 eV can occur at the respective 50-50 composition points. The significance of such large interactions between valence and low-lying Rydberg states is considered in terms of the properties of the resulting mixed CI states, particularly with reference to the oscillator strengths for the pertinent ground state transitions and also the spatial extension of the corresponding upper orbitals. It is thereupon argued that such mixings have important consequences in the spectra of a wide variety of systems, including those of O2, ethylene and ethane. 相似文献
993.
The Auger electron spectrum of water vapour has been recorded and analyzed. For the analysis, an approximate formula for calculating the intensities of the Auger electron lines is derived. It is shown, that the calculated intensities along with theoretical energies of the Auger transitions account well for the observed spectrum. In particular, new assignments in terms of transitions to triplet final states are suggested. 相似文献
994.
The corresponding 2-(2-furyl)naphth[1,2-d]imidazoles were obtained by heating Schiff bases, prepared from 1,2-naphthalenediamine and furfural and 5-bromo- and 5-nitrofurfurals, in nitrobenzene. 2-[-(2-Furyl)vinyl]naphth[1,2-d]imidazoles were synthesized by condensation of 2-methylnaphth[1,2-d]imidazole with furfural and 5-bromo- and 5-nitrofurfural. The methylation, nitration, and acetylation of the compounds obtained were studied, and the replacement of the bromine atom in the furan ring by a nitro group was also investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1555–1557, November, 1972. 相似文献
995.
Sunit S. Dixit A. B. Deshpande S. L. Kapur 《Journal of polymer science. Part A, Polymer chemistry》1971,9(5):1167-1172
The polymerization of acrylonitrile with the homogeneous catalyst system of VCl4–AlEt3 in acetonitrile at 40°C has been investigated. The rate of polymerization is found to be first-order with respect to monomer and inversely proportional to the catalyst concentration. The overall activation energy for this catalyst system is 10.97 kcal/mole. The inverse proportionality of rate of polymerization with the catalyst concentration is attributed to the permanent complex formation between the catalyst complex and acrylonitrile, and a reaction scheme is proposed. 相似文献
996.
Summary The reduction of complex esters and carbonyl compounds in hydrocarbon media by aluminum hydrides of the alkali metals results in the formation of the corresponding alcohol in high yield. The reduction of nitriles proceeds with the formation of primary amines. 相似文献
997.
Summary A method has been devised for the synthesis of -lacrams from amides of -ha!ocarboxylic acids. Some new azetidinones with residues containing carboxyl groups on the nitrogen have been piepated. The method permits the conversion of $-amino acids trio difficulty accessible mixed (secondary) amino acids.This paper is publised under the regulations governing Brief Communications. 相似文献
998.
Summary Tokaj wines (Szamorodni and Aszu wines) of Hungarian origin were investigated on the basis of free amino acids and biogenic
amines. The separation and determination of these compounds was performed by an amino acid analyser equipped with an ion-exchange
resin column. The total amount of free amino acids and biogenic amines was higher in Aszu wines than in Szamorodni wines.
The main amino acids were proline and arginine, while the major biogenic amines were tyramine and putrescine. The free amino
acid and biogenic amine content of Aszu wines depended on the vineyards the wines originated from.
Presented at Balaton Symposium '01 on High-Performance Separation Methods, Siófok, Hungary, September 2–4, 2001 相似文献
999.
Variously cross-linked poly(methylmethacrylates) (PMMAs) are synthesized with three additives incorporated at theoretically 1000 microg of the additive per gram of prepared polymer. The additives are Irganox 1010, Irganox 1076, and Irgafos 168. The in-house" synthesized polyacrylates are then subjected to supercritical fluid extraction (SFE) to determine if additive recovery is a function of percent cross-linking. Although considerable work in this regard has been performed with non-cross-linked polyolefins, the literature is lacking regarding polyacrylates. Some additive degradation apparently occurs during the synthesis, as judged by the increased complexity of the extract high-performance liquid chromatographic trace and the low percent recoveries observed especially for the Irganoxes. For low polymer cross-linking (1%), it appears that both PMMA synthetic reproducibility and readily observed polymer swelling during SFE are serious issues that adversely affect additive percent recovery and precision of results. Higher percent cross-linking yields more consistent analytical data than low percent cross-linking, even though the amount of additive extracted in all PMMA samples (regardless of cross-linking percentage) is essentially the same whether the extraction is via SFE or liquid-solid extraction with methylene chloride. Results for comparably cross-linked poly(ethylmethacrylate) and poly(butylmethacrylate) are similar to PMMA. 相似文献
1000.
A. A. Avetisyan I. L. Aleksanyan A. A. Pivazyan 《Russian Journal of Organic Chemistry》2006,42(5):739-741
4-Hydroxy-2-methyl-3-(2-chloro-2-propenyl)quinoline was prepared by O-allylation of 4-hydroxy-2-methylquinoline followed by the Claisen rearrangement of the 2-methyl-4-(2-chloro-2-propenyloxy)quinoline obtained. Chemical modifications of 4-hydroxy-2-methyl-3-(2-chloro-2-propenyl)quinoline resulted in the synthesis of 4-amino-2-methyl-3-(2-methyl-3-indolyl)quinoline. 相似文献