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21.
Saposhnikoviae Radix (SR), the dried root of Saposhnikovia divaricata (Turcz.) Schischk. (Umbelliferae), is commonly used as a traditional Chinese medicine. In this study, a rapid and accurate method was firstly, developed for the qualitative analysis of SR by high-performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q-TOF-MS/MS). A total of 45 compounds were identified or tentatively characterised, including 13 chromones, 28 coumarins and four others. Among them, 16 compounds were identified from SR for the first time. In addition, six chromones reference standards, including two isolated compounds of 3′-O-angeloylhamaudol and norcimifugin from the extraction of SR, were used to study the fragmentation pathways of chromones. The developed method was effective for characterising the compounds of SR, and the results of the study enriched the understanding of the chemical connotation. 相似文献
22.
Vladislav Yu. Korotaev Alexey Yu. BarkovIgor B. Kutyashev Alexander V. SafryginVyacheslav Ya. Sosnovskikh 《Tetrahedron》2014
3-Formylchromones react with ylidenemalononitriles in the presence of triethylamine in dichloromethane to produce the target electron-deficient dienes connected to the chromone system with excellent E-selectivity and in good yields. In a similar manner, their reaction with ethyl α-cyano-β-methylcinnamate gave a mixture of E,Z- and E,E-isomeric chromonyl dienes, from which the former could be isolated in a pure state by crystallization. 相似文献
23.
T. V. Shokol V. A. Turov V. V. Semeniuchenko N. V. Krivokhizha V. P. Khilya 《Chemistry of Heterocyclic Compounds》2006,42(4):500-505
The recyclization of 2-R-7-hydroxy-3-(4-phenyl-1,2,4-triazol-3-yl)chromones using the binucleophiles hydroxylamine, hydrazine,
or guanidine gave isoxazoles, 2-aminochromones, pyrazoles, or pyrimidines with a 4-phenyl-1,2,4-triazol-3-yl substituent.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 571–578, April, 2006. 相似文献
24.
The synthesis of a series of new nine 3-benzoyl-2-benzylchromones is developed through a classical and an optimized Kostanecki-Robinson method involving an o-hydroxyphenyl-β-diketone and an acid anhydride. The different spectrokinetic studies carried out in solution and in polymer matrixes have highlighted the main structure/photochromic parameters relationships and the influence of the medium on the photochromic properties. 相似文献
25.
V. Ya. Sosnovskikh A. Yu. Sizov B. I. Usachev M. I. Kodess V. A. Anufriev 《Russian Chemical Bulletin》2006,55(3):535-542
Reactions of chromones with methyl ketoximes in the presence of lithium diisopropylamide follow the nucleophilic 1,2-addition
mechanism to give spiro[4H-chromene-4,5′-isoxazolines] in good yields. The isoxazoline ring in spiro[4H-chromene-4,5′-isoxazolines] undergoes opening under the action of conc. H2SO4, yielding α,β-unsaturated oximes. Their nitrosation and bromination lead to the corresponding spiroisoxazolines, while the
Beckmann rearrangement, to α,β-unsaturated amides. The latter are also formed directly from spiro[4H-chromene-4,5′-isoxazolines] under the action of PCl5. N-Substituted acetophenone hydrazones in the presence of lithium diisopropylamide react at the C(4) atom of 2-trifluoromethylchromone,
while acetophenone anil under the same conditions, at the C(2) atom.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 516–522, March, 2006. 相似文献
26.
Vyacheslav Ya. Sosnovskikh Roman A. Irgashev Pavel A. Slepukhin 《Tetrahedron letters》2007,48(36):6297-6300
3-(Trifluoroacetyl)chromones undergo heterodiene cycloaddition to 3,4-dihydro-2H-pyran and 2,3-dihydrofuran under mild conditions, producing novel fused pyrans with high stereoselectivity and in good yields. These pyrans were transformed into functionalized pyridines on treatment with ammonium acetate in ethanol. The structures of the endo-cycloadducts were established by 1H NMR spectroscopy and X-ray diffraction analysis. 相似文献
27.
The condensation of 1,3-bis-silyl enol ethers with benzopyrylium triflates, generated in situ by the reaction of chromones with Me3SiOTf, afforded functionalized 2,3-dihydrobenzopyrans; treatment of the latter with NEt3 or BBr3 resulted in a domino retro-Michael-aldol-lactonization reaction and the formation of a variety of 7-hydroxy-6H-benzo[c]chromen-6-ones. The hydroxy group was functionalized by using Suzuki cross-coupling reactions. The methodology reported was applied to the synthesis of the natural product autumnariol and a new fluorescence dye, which exhibits promising optical properties. 2,3-Dihydro-1H-4,6-dioxachrysen-5-ones were prepared by condensation of chromones with 1,3-bis-silyl enol ethers containing a remote chloride group, domino retro-Michael-aldol-lactonization, and an intramolecular Williamson reaction. 相似文献
28.
V. Ya. Sosnovskikh R. A. Irgashev I. A. Khalymbadzha 《Russian Chemical Bulletin》2007,56(8):1608-1611
Reaction of 3-(trifluoroacetyl)chromones with ethylenediamine and o-phenylenediamine depending on the nature of substituents and the reaction conditions afforded either mono-adducts, 3-[(2-aminoethyl)aminomethylidene]-and
3-[(2-aminophenyl)aminomethylidene]-2-hydroxy-2-(trifluoromethyl)chroman-4-ones, or bis-adducts, N,N′-ethylenebis-and N,N′-o-phenylenebis[3-aminomethylidene-2-hydroxy-2-(trifluoromethyl)chroman-4-ones].
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1548–1551, August, 2007. 相似文献
29.
Vyacheslav Ya Sosnovskikh Boris I UsachevDmitri V Sevenard Gerd-Volker Röschenthaler 《Tetrahedron》2003,59(15):2625-2630
The redox reaction of 2-trifluoromethylchromones with ethyl mercaptoacetate in the presence of triethylamine results in the formation of 1,2-dihydrothieno[2,3-c]chromen-4-ones and diethyl 3,4-dithiadipate in high yields. Oxidation of the first compounds with nitrogen dioxide gave 1,2-dihydrothieno[2,3-c]chromen-3,4-diones which were converted into thieno[2,3-c]chromen-4-ones. 相似文献
30.
T. V. Shokol V. A. Turov A. V. Turov N. V. Krivokhizha V. V. Semenyuchenko V. P. Khilya 《Chemistry of Heterocyclic Compounds》2005,41(11):1411-1418
The condensation of 4-phenyl-1,2,4-triazol-3-ylacetonitrile with 2-methyl-, 4-ethylresorcinol, and with pyrogallol gave α-(4-phenyl-1,2,4-triazol-3-yl)-2,4-dihydroxyacetophenones.
Upon treatment with acid anhydrides and chlorides and subsequent hydrolysis these form 7-hydroxy-3-(4-phenyl)-1,2,4-triazol-3-yl)chromones
with different substituents in both the benzene and the pyrone rings.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1676–1684, November, 2005. 相似文献