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The reaction of o-ethynylbenzoic acids hydrazides with base has been studied. In the presence of a strong donor substituent (1,5-dimethylpyrazol-4-yl)
it has been found that an unusual cyclization route occurs to give the corresponding benzopyridazinone instead of the expected
isoindolinone.
Dedicated to Academician B. A. Trofimov in his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 67-70, January, 2009. 相似文献
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The products of the condensation of aliphatic aldehydes with N-(2-aminobenzoyl)-N-methylhydrazine exist in DMSO-d6 solution as tautomeric mixtures of linear aldohydrazone and cyclic benzo-1,3,4-triazepine forms. The linear tautomer predominates
for 2-aminobenzoyl-N-methylhydrazones of aromatic aldehydes. A tautomeric equilibrium is observed in DMSO-d6 for the products of the condensation of the hydrazide of 2-aminobenzoic acid with a series of aldoses. This equilibrium exists
between α,β-isomeric pyranose forms and the open aldosohydrazone form. Isomeric conversion to the seven-membered benzo-1,3,4-triazepine
form is observed for the products of the condensation of aldoses with N-(2-aminobenzoyl)-N-methylhydrazine. 相似文献
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Electrophilic cyclization of N′-(2-alkynylbenzylidene)hydrazides with I2, Br2, or ICl under mild conditions is described. This reaction proceeds smoothly in dichloromethane at room temperature, which provides a useful method for the synthesis of functionalized isoquinolinium-2-yl amide. 相似文献
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[reaction: see text] The Bergman cyclization of benzannelated enediynes is highly sensitive to ortho substitution. This finding opens possibilities for the rational design of conformer-specific and pH-dependent DNA-cleaving agents. 相似文献
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The ring closure and rearrangement of N-2-aminobenzoyl -N-methylhydrazones of β-dicarbonyl compounds
Melinda Gál Ödön Fehér Endre Tihanyl Gyula Horváth Gyula Jerkovich 《Tetrahedron》1982,38(19):2933-2938
A novel rearrangement was observed during the cyclization of N-(2-aminobenzoyl)-N-methylhydrazones of β-dicarbonyl compounds, leading to pyrazole derivatives 2,4, and 5 depending on substituents and the reaction media. 相似文献
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Treatment of 2-(phenylsulfinyl)indoles bearing a pendant nucleophile at C(3) with Tf(2)O/lutidine triggers a Pummerer-like cyclization to furnish 3,3-spirocyclic-2-(phenylthio)indolenine products, which can, in turn, be hydrolyzed to 3,3-spirocyclic oxindoles. [reaction: see text] 相似文献
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The diastereoselective oxidative cyclization of a beta-oxygenated tryptophan derivative is reported. This process, which utilizes a new variant of the Pummerer reaction, may have application in TMC-95A synthesis. 相似文献
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Patrick S. Mariano Peter L. Huesmann Ralph L. Beamer Debra Dunaway-Mariano 《Tetrahedron》1978,34(17):2617-2626
The Diels-Alder chemistry of a series of 1-vinyl-2-pyridones using a variety of dienophilic species including dimethyl acetylenedicarboxylate, benzyne, maleic anhydride and methyl vinyl ketone has been explored in order to determine the generality of this method for generation of N-vinylisoquinuclidines. In general, the cycloaddition reactions lead to modestly high yeilds of the azabicyclooctane products. In the course of these studies, we noted that retro-Diels-Alder reactions of N-vinylisoquinuclidienones lead to generation of N-vinylisocyanates and a benzene fragment while the corresponding mono-unsaturated isoquinuclidenones form the corresponding pyridones by elimination of an ethylene unit. Lastly, the regio- and stereochemical courses for the π2+ π4 addition reactions of methyl vinyl ketone and 1-vinyl-2-pyridones were investigated. The major products from these reactions appear to result from reaction pathways predicted to be of low energy using first-order molecular orbital methods. 相似文献
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Roberto M. Tovar Kyle P. Johnson Keith Ashline Jorge M. Seminario 《International journal of quantum chemistry》2008,108(9):1546-1554
The current–voltage characteristics of small aliphatic chains of alkanes, alkenes, alkynes, and oligophenylene‐ethylenes, with and without substituents and terminated in sulfur attached nanosized gold electrodes are determined using ab initio procedures for discrete and extended systems in a density functional theory‐Green function's approach where most of the chemistry is considered. It is found that the current–voltage characteristics of small molecules can be tailored by the addition of substituents. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 相似文献
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Akira Mori Corresponding author Katsuyuki Uno Kanji Kubo Nobuo Kato Hitoshi Takeshita Ken Hirayama 《Liquid crystals》2013,40(2):285-294
Three types of 5-alkoxy-2-benzoylaminotropones, containing an electron-donating group and seven types of derivatives with electron-withdrawing groups on the benzoyl group, were prepared in order to study the thermal ranges of the mesophases exhibited. The troponoid amides had higher transition temperatures than the corresponding troponoid esters and benzenoid amides. From the 1H NMR spectroscopic measurements and X-ray crystallographic analysis of 5-butoxy-2-(4-methoxybenzoylamino)tropone, it was observed that the benzoyl carbonyl group faced to the H-3 of the tropone ring to form an intramolecular hydrogen bond between the tropone carbonyl and the amide NH groups. The intramolecular hydrogen bonding of the troponoid amides made the molecules flat, inducing strong π–π intermolecular interactions between head-to-tail dimers and so reduced the possibility of intermolecular hydrogen bonding between the NH group and the carbonyl group of neighbouring molecules so decreasing melting points. Electron-donating groups enhanced the appearance of nematic phases while electron-withdrawing groups promoted smectic A phases. 相似文献
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Akira Mori Katsuyuki Uno Kanji Kubo Nobuo Kato Hitoshi Takeshita Ken Hirayama Seiji Ujiie 《Liquid crystals》2004,31(2):285-294
Three types of 5-alkoxy-2-benzoylaminotropones, containing an electron-donating group and seven types of derivatives with electron-withdrawing groups on the benzoyl group, were prepared in order to study the thermal ranges of the mesophases exhibited. The troponoid amides had higher transition temperatures than the corresponding troponoid esters and benzenoid amides. From the 1H NMR spectroscopic measurements and X-ray crystallographic analysis of 5-butoxy-2-(4-methoxybenzoylamino)tropone, it was observed that the benzoyl carbonyl group faced to the H-3 of the tropone ring to form an intramolecular hydrogen bond between the tropone carbonyl and the amide NH groups. The intramolecular hydrogen bonding of the troponoid amides made the molecules flat, inducing strong π-π intermolecular interactions between head-to-tail dimers and so reduced the possibility of intermolecular hydrogen bonding between the NH group and the carbonyl group of neighbouring molecules so decreasing melting points. Electron-donating groups enhanced the appearance of nematic phases while electron-withdrawing groups promoted smectic A phases. 相似文献
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2-Aryl-5,6-dihydro-4H-1,3-oxazin-5-ones were obtained in the reaction of 1-diazo-3-benzamidopropan-2-ones with acidic agents.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1324–1326, October, 1980. 相似文献
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M. S. Shvartsberg A. V. Piskunov M. A. Mzhel'skaya A. A. Moroz 《Russian Chemical Bulletin》1993,42(8):1357-1363
A general method for the synthesis of substituted fused polycyclic compounds containing a 4-alkylamino or 4-dialkylaminopyridine cycle has been proposed. The method includes the addition of primary or secondary amines to vicinal (acylethynyl)arylamines followed by the cyclization of the adducts under acidic or basic catalysis conditions. Various aminonaphthoquinolinediones and aminoquinolines have been prepared in high yields by this method.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1423–1429, August, 1993. 相似文献
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The title compound was synthesized by the cyclization of α,β-dibromonitrostyrene with three moles of cyclohexylamine. Evidence for the steric course of the cyclization reaction is also reported. 相似文献