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921.
V. Milata D. Ilavsky M. Chudík Ľ. Zalibera J. Leško M. Seman A. Belicova 《Monatshefte für Chemie / Chemical Monthly》1995,126(12):1349-1358
Summary Catalytic hydrogenation of 2,3-diphenyl-6-nitroquinoxaline led to the corresponding amine1 which in turn afforded products3a-i on reaction with alkoxymethylene derivatives2a-i. Thermal cyclization of3b and3f yielded substituted pyrazinoquinolones5b and5f, respectively. Optimal conditions for the successful hydrolysis of ester5b were found. The structures of all products were deduced from their IR, UV,1H, and13C NMR spectroscopic data.Dedicated to Prof.F. Sauter on the occasion of his 65th birthday 相似文献
922.
S. G. Mikhalenok N. M. Kuz'menok A. M. Zvonok 《Chemistry of Heterocyclic Compounds》2005,41(8):977-986
It was established that, in addition to ethyl 4-aryl-3-(2,3-epoxyalkanoyl)-4,5-dihydro-1H-pyrazole-5-carboxylates, the reaction
of diazoacetic ester with β-arylacryloyloxiranes also gives ethyl 4-aryl-3(5)-(3-hydroxy-2-methylalkanoyl)-1H-pyrazole-5(3)-carboxylates.
The latter are formed from the tautomeric ethyl 4-aryl-5-(2,3-epoxyalkanoyl)-4,5-dihydro-1H-pyrazole-3-carboxylates as a result
of intramolecular oxidative-reductive disproportionation.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, 1150–1160, August, 2005. 相似文献
923.
By alternating‐current electrochemical technique crystals of copper(I) π‐complex with 1‐allylpyridinium chloride of [C5H5N(C3H5)][Cu2Cl3] ( 1 ) composition have been obtained and structurally investigated. Compound 1 crystallizes in monoclinic system, space group C2/c a = 24.035(1) Å, b = 11.4870(9) Å, c = 7.8170(5) Å, β = 95.010(5)°, V = 2150.0(2) Å3 (at 100 K), Z = 8, R = 0.028, for 4836 independent reflections. In the structure 1 trigonal‐pyramidal environment of π‐coordinated copper(I) atom is formed by a lengthened to 1.376(2) Å C=C bond of allyl group and by three chlorine atoms. Other two copper atoms are tetrahedrally surrounded by chlorine atoms only. The coordination polyhedra are combined into an original infinite (Cu4Cl62—)n fragment. Structural comparison of 1 and the recently studied copper(I) chloride π‐complexes with 3‐amino‐, 2‐amino‐, 4‐amino‐1‐allylpyridinium chlorides of respective [LCu2Cl3] ( 2 ), [L2Cu2Cl4] ( 3 ), and [LCuCl2] ( 4 ) compositions allowed us to reveal the trend of the inorganic fragment complication which depends on pKa (base) value of the corresponding initial heterocycle. 相似文献
924.
925.
T. I. Mukhanova L. M. Alekseeva A. S. Shashkov V. G. Granik 《Chemistry of Heterocyclic Compounds》2004,40(1):16-21
Derivatives of furo[2,3-f]quinoline were synthesized by the reaction of the enamines of acetylacetone and benzoylacetone with 2-methoxycarbonyl-4-oxo-5,8-quinolinequinone. A derivative of pyrrolo[2,3-h]quinoline was obtained from N-benzyl--aminocrotonic ester. 相似文献
926.
Pavel V. Pasternak 《Journal of fluorine chemistry》2004,125(12):1853-1868
A new CF2X-analogue of 1,1-bis(trifluoromethyl)-2,2-dicyanoethylene (X = P(O)(OEt)2), diethyl (1,1-difluoro-3,3-dicyano-2-trifluoromethylallyl)phosphonate, has been synthesized from diethoxyphosphoryl pentafluoroacetone 1. A similar phosphoryl analogue of ethyl 3,3-dicyano-2-trifluoromethylacrylate, ethyl 3,3-dicyano-2-[(diethoxyphosphoryl)difluoromethyl]acrylate, has been obtained from ethyl 3-(diethoxyphosphoryl)-3,3-difluoro-2-oxopropionate 2. By heterocyclization of these new ethylenes with 3-methyl-2-pyrazoline-5-ones, 3(5)-aminopyrazoles, dimedone, 2-aminopyridines, 1-aryl-3-methyl-5-aminopyrazoles, 1,3,3-trimethylisoquinolines, as well as by condensation with anilines and ketones, the difluoromethylphosphonate-substituted derivatives of 1,4-dihydropyrano[2,3-c]pyrazole, 4,5-dihydropyrazolo[1,5-a]pyrimidine, 5,6,7,8-tetrahydro-4H-chromene, 2H-pyrido[1,2-a]pyrimidine, 4,7-dihydro-1H-pyrazolo[3,4-b]pyridine, 1,4-dihydropyridine, 4,5,6,7-tetrahydro-1H-[1]pyrindine, 1,4,5,6,7,8-hexahydroquinoline, and 6,7-dihydro-2H-pyrido[2,1-a]isoquinoline have been obtained in one stage. 相似文献
927.
Masayuki Hoshi Souichi Suzuki Shingo Saitoh Mitsuhiro Okimoto Kazuya Shirakawa 《Tetrahedron letters》2007,48(1):119-124
A convenient, efficient and stereoselective synthesis of a range of bis(alk-3-en-1-ynyl)benzenes with E- and Z-configuration is described. The protocol involves Cu-mediated cross-coupling reaction of (E)- and (Z)-alk-1-enyldisiamylboranes with (trimethylsilyl)ethynyl bromide and Pd/Cu-catalyzed cross-coupling reaction with diiodobenzene. The sequential cross-coupling reaction proceeds readily under extremely mild conditions in a one-pot manner to afford bis(alk-3-en-1-ynyl)benzenes in good to excellent yields. The optical properties of the products are also described. 相似文献
928.
A new ion-pair complex, [1-(4′-chlorobenzyl)-4-aminopyridinium](+)bis(maleonitrile-dithiolato)nickel(−),[ClbzPyNH2][Ni(mnt)2] (1), has been prepared and characterized. X-ray single crystal structure conforms that the Ni(mnt)2− anions and [ClbzPyNH2]+ cations of 1 form completely segregated uniform stacking columns with the Ni?Ni distance 3.944 Å in the Ni(mnt)2− stacking column. The temperature dependence of the magnetic susceptibility reveals that 1 undergoes a magnetic transition, and exhibits ferromagnetic interaction in the high-temperature phase and spin gap system in the low-temperature phase. 相似文献
929.
Malose J. Mphahlele Ahmed M. El-Nahas Tarek M. El-Gogary 《Journal of Molecular Structure》2004,690(1-3):151-157
The geometries of the title compounds were probed in solution, solid and gas states using spectroscopic methods, X-ray crystallography and quantum chemical techniques. The exclusive existence of the NH-4-thiones in solution (NMR and PCM-B3LYP(MP2)/6-31+G(d) calculations) and solid state (FT-IR and X-ray) is also corroborated by comparison of their spectroscopic data with those of the corresponding 2-aryl-1-methylquinoline-4(1H)-thione derivatives. The co-existence of the quinoline-4-thione and quinoline-4-thiol (4-mercaptoquinoline) isomers in the gas phase is confirmed by mass spectrometry and the preponderance of the 4-thiol is supported by quantum chemical techniques (PM3, MP2 and B3LYP). 相似文献
930.
Ewa?Cholewa Ian?Burgess Julia?Kunze Jacek?LipkowskiEmail author 《Journal of Solid State Electrochemistry》2004,8(10):693-705
Electrochemical measurements including cyclic voltammetry, differential capacity, and chronocoulometry have been used to characterize the adsorption behaviors of the zwitterionic surfactant
N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (DDAPS) on the Au(111) electrode surface. The thermodynamics of the ideally polarized electrode have been employed to determine the Gibbs excess and the Gibbs energy of adsorption. The results show that the adsorption of DDAPS has a multistate character. The first two states are observed at potentials close to zero charge. At low bulk DDAPS concentrations, it corresponds to the formation of a film of nearly flat adsorbed molecules. At higher concentrations it is converted into a hemimicellar state. The second state is formed at negative potentials and charge densities close to 0 C cm–2. It corresponds to a film of tilted molecules oriented with the hydrocarbon tail towards the metal and the polar head toward the solution.Dedicated to Professor Zbigniew Galus on the occasion of his 70th birthday and in recognition of his many contributions to electrochemistry. 相似文献