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1.
A simple one-step synthetic methodology for stereoselective synthesis of E- and Z-3-bromo-2-vinyl chromones in quantitative yield in polar solvents under ambient conditions without the use of catalysts is reported. 相似文献
2.
V. Ya. Sosnovskikh 《Russian Chemical Bulletin》1998,47(2):354-356
Condensation of 2-hydroxy-4,6-dimethylacetophenone with trifluoro- and trichloroacetonitriles gives 2-amino-5,7-dimethyl-2-trifluoro(trichloro)methyl-4-chromanones.
The condensation with 2,2,3,3-tetrafluoropropionitrile, perfluorovaleronitrile, and benzonitrile stops at the stage of formation
of the corresponding enamines.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 362–363, February, 1998. 相似文献
3.
T. V. Shokol O. A. Lozinskii T. M. Tkachuk V. P. Khilya 《Chemistry of Natural Compounds》2009,45(3):350-355
7-Hydroxy-3-phenoxy-8-formylchromones were synthesized using the Duff reaction and were reacted with 2,4-dinitrophenylhydrazine
to produce hydrazones and with an excess of hydrazine hydrate to produce the pyrazole recyclization products. Derivatives
of α-pyrono[2,3-f]chromones were synthesized using the Knoevenagel condensation with 2-azahetarylacetonitriles and the Perkin
reaction.
Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 298–302, May–June, 2009. 相似文献
4.
The reactions of 3-chloro-2-(polyfluoroalkyl)chromones with hydroxylamine in the presence of sodium acetate proceed with ring contraction to form benzofuran derivatives. 相似文献
5.
Reactions of 3-substituted chromones (3-formylchromone, 3-formylchromone-3-oxime, and 3-cyanochromone) with hydroxylamine in alkaline medium were reinvestigated, and a proof of structures and a probable reaction pathway are presented. Syntheses of 2-aminochromone-3-carboxamide, 3-amino-4H-chromeno[3,4-d]isoxazol-4-one, and 3-(diaminomethylene)chroman-2,4-dione were developed. 相似文献
6.
T. V. Shokol V. V. Semenyuchenko V. P. Khilya 《Chemistry of Heterocyclic Compounds》2005,41(5):673-678
By recyclization of 2-R-6-ethyl-7-hydroxy(methoxy)-3-(5-phenyl-1,3,4-thiadiazol-2-yl)chromones when treated with hydrazine hydrate and phenylhydrazine, we synthesized 5-phenyl-2-(3-R-5-R1-1H-pyrazol-4-yl)-1H-1,3,4-thiadiazoles and 2-(3-R-5-R1-1-phenyl-1H-pyrazol-4-yl)-5-phenyl-1H-1,3,4-thiadiazoles. We confirmed the structure of the latter from 1H NMR spectra.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 781–787, May, 2005. 相似文献
7.
T. V. Shokol V. V. Semenyuchenko S. V. Shilin A. V. Turov A. S. Ogorodniichuk V. P. Khilya 《Chemistry of Natural Compounds》2005,41(5):533-538
Chromones modified by triazole, amino acids, and dipeptides were prepared by condensation of the N-hydroxysuccinimide ester
of 2-(6-ethyl-4-oxo-3-(4-phenyl-4H-1,2,4-triazol-3-yl)-4H-chromen-7-yloxy)acetic acid with salts of amino acids or dipeptides.
The dipeptide derivatives were also synthesized by extending the chain of amino acids.
__________
Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 435–439, September–October, 2005. 相似文献
8.
Bei-Xi Jia Qian-Qian Huangfu Feng-Xiao Ren Lu Jia Yan-Bing Zhang Hong-Min Liu 《Natural product research》2015,29(9):800-806
This article marks the first report on high-performance liquid chromatography (HPLC) coupled with diode-array detection (DAD) and quadruple time-of-flight mass spectrometry (Q-TOF/MS) for the identification and quantification of main bioactive constituents in Baeckea frutescens. In total, 24 compounds were identified or tentatively characterised based on their retention behaviours, UV profiles and MS fragment information. Furthermore, a validated method with good linearity, sensitivity, precision, stability, repeatability and accuracy was successfully applied for simultaneous determination of five flavonoids and one chromone in different plant parts of B. frutescens collected at different harvest times, and their dynamic contents revealed the appropriate harvest times. The established HPLC-DAD-Q-TOF/MS using multi-bioactive markers was proved to be a validated strategy for the quality evaluation on both raw materials and related products of B. frutescens. 相似文献
9.
New RF-containing benzofuran derivatives of 2-oxa-7-thiabicyclo[3.2.1]octane and dihydrothienopsoralens were synthesized from 7-polyfluoroalkylnorkhellins and alkyl mercaptoacetates. 相似文献
10.
The reaction of 2-hydroxy-2-polyfluoroalkylchroman-4-ones with hydrazine affords 5-hydroxy-3-(2-hydroxyaryl)-5-polyfluoroalkyl-2-pyrazolines, whereas 2-polyfluoroalkylchromones under similar conditions produce 3(5)-(2-hydroxyaryl)-5(3)-polyfluoroalkylpyrazoles. 5-(2-Hydroxyaryl)-1-methyl-3-polyfluoroalkylpyrazoles were synthesized in the reaction with methylhydrazine, and the reaction with phenylhydrazine afforded regioisomeric 3(5)-(2-hydroxyphenyl)-1-phenyl-5(3)-polyfluoroalkylpyrazoles. 相似文献