It was established by the methods of 1H and 13C NMR spectroscopy that the oximohydrazones and bis(hydrazones) of aroylacetic aldehydes exist in the form of the corresponding 5-hydrazino- and 5-hydroxyamino-3-aryl-2-pyrazolines and -2-isoxazolines. The features of the aromatization of these compounds to the corresponding pyrazoles and isoxazoles were studied. Data on the mass-spectral study of the 5-hydroxyamino-2-pyrazoline-5-hydrazino-2-isoxazoline tautomerism in the gas phase are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 927–935, July, 1989. 相似文献
3-Acetylaminomethyl-2-benzoxazolones are obtained by Beckmann rearrangement of the anti-oximes of 3-acetonyl-2-benzoxazolones. The isomeric 3-(N-methylcarbamoylmethyl)-2-benzoxazolones are synthesized by alkylation of 2-benzoxazolone with chloroacetic acid, followed by reaction of the 3-carboxymethyl-2-benzoxazolones obtained with thionyl chloride and methylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1185–1188, September, 1985. 相似文献
This review concerns the cyclization of thiosemicarbazones and thiocarbhydrazones of carbonyl compounds leading to the title heterocycles. We examine the irreversible cyclization by the action of oxidizing agents or as the result of acylation or alkylation as well as the ring—chain tautomerism. The effect of the substitution and solvent on the equilibrium of the thiosemicarbazones with some of the possible heterocyclic tautomeric forms was examined. The usefulness of these data for predicting the results of their irreversible cyclization was discussed.Dedicated to Professor A. R. Katritzky on the occasion of his sixty-fifth birthday.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 991–1005, July, 1993. 相似文献
The homolytic telomerization of vinyltrimethylsilane by 5,5-dimethyl-1,3-dioxane follows three principal routes, with the formation of 2- and 4-substituted 5,5-dimethyl-1, 3-dioxanes and a formate ester. The rings in the reaction products (2-trimethylsilylethyl- and 4-trimethylsilylethyl-5,5-dimethyl-1,3-dioxane) exist in the chair conformation. The substituants in the 2- and 4-positions of the dioxane ring occupy equatorial positions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1031–1035, August, 1986. 相似文献
The flow pattern of a viscous imcompressible fluid past a finite body is well known; an approximate solution of the related problem can, for example, be found in the book by Landau and Lifshits [1]. Finn [2] made a rigorous and exhaustive study of plane-parallel flows. No fundamental difficulties arise in passing from the motion of an incompressible fluid to a transonic flow of a compressible gas, however the velocity field is different, when the velocity of particles becomes critical at infinity.
The pattern of a sonic flow past a body of circular cross-section was investigated in paper [3]. This paper deals with perturbations associated with the creation of lift acting on an arbitrary body in a three-dimensional flow. When solving this problem it is necessary to consider not only the external stream, but also the laminar vortex trail because of the velocity vector transverse components becoming infinitely great, if functions defining these are formally extended into the trail area. This difficulty arises in investigations of three-dimensional flows only. The solution defining perturbation damping in an axisymmetric sonic stream of a dissipative gas has in its first approximation one singular point only, and does not contain any other singularities along the axis of symmetry [3].
The external stream pattern is essentially formed by the action of normal viscous stresses and the longitudinal component of the heat flux vector, while the distribution of gas parameters in the laminar trail is defined by tangential stresses. The conjunction of solutions valid for each of these areas makes the closure of the problem, and the determination of all necessary parameters possible. 相似文献
,-Dichloropropionitrile reacts with unsaturated compounds in the presence of complex initiating systems based on metal carbonyls. The systems based on iron pentacarbonyl are the most efficient.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1595–1596, August, 1995.The work was financially supported by the Russian Foundation for Basic Research (Project No. 93-03-04497). 相似文献
The products of the addition of tetracyanoethylene to ketones react smoothly with aliphatic, aromatic, and heterocyclic aldehydes to give 4,8,8-tricyano-3-imino-2, 6-dioxabicyclo[2.2.2]octanes. The structures of the reaction products were confirmed by 13C, IR, and mass spectral data.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1462–1466, November, 1984. 相似文献
The reaction between quinoxaline and benzopyridine in acetic anhydride in the presence of zinc dust gives a quinoxaline anion and a benzopyridine N-acetyl radical, which recombine to give the previously unknown N-acetyl dihydrobenzo-pyridine derivative of 1,2-dihydroquinoxaline. Under these conditions, quinoxaline alone gives 1,4-diacetyl-1,4-dihydroquinoxaline and 1-acetyl-2-(1,2-dihydroquinoxalyl-2)-1,2-dihydroquinoxaline.Previous communication, [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 967–973, July, 1985. 相似文献
An analysis of the PMR spectra (using double resonance) of the isomeric 3-, 6-, 7-, and 8-methyl and 7-ethyl-5-azacinnolines, and also of 7-methyl-8-azacinno-line has shown the presence in these structures of a considerable localization of the C5-C6 and C7-C8 bonds, which has been confirmed by the results of a quantum-chemical calculation by the PPP method.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 541–543, April, 1980. 相似文献
The CH2 = CHX olefins form a series relative to their reactivity in reactions with 2-phenyl-1,3-dioxolan-2-yl radicals, which qualitatively correlates with the electron-withdrawing capacity of substituent X: CN CO2Me >> SiMe3 C4H9. This behavior indicates that the dioxolanyl radical is nucleophilic.A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1663–1666, July, 1992. 相似文献