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101.
The reactions of 3,3-dialkyl-2,3-dihydro-6-trifluoromethyl-4-pyrones with hydroxylamine hydrochloride afforded regioisomeric
3(5)-(1,1-dialkyl-2-hydroxyethyl)-5-hydroxy-5(3)-trifluoromethyl-Δ2-isoxazolines depending on the reaction conditions. The title compounds were also prepared from 2,2-dialkyl-5-amino-1-hydroxy-6,6,6-trifluorohex-4-en-3-ones.
The above dihydropyrones reacted with hydroxylamine (base) to yield 3-(1,1-dialkyl-2-hydroxyethyl)-5-hydroxy-5-trifluoromethyl-Δ2-isoxazolines.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1334–1339, July, 1999. 相似文献
102.
研究了双(苯并噁唑)芪的光物理行为和光顺反异构化反应,对这类化合物的发光光谱不依赖于溶剂极性的原因进行了初步讨论。异构化反应中,发现乙二醇引入时会加速该化合物反-顺异构化和抑制顺-反过程的回复,其原因可能是与生成了顺式异构体两个苯基苯并噁唑间的氢键有关。 相似文献
103.
104.
A. A. Trifonov E. N. Kirillov E. A. Fedorova N. P. Makarenko M. N. Bochkarev H. Schumann S. Muehle 《Russian Chemical Bulletin》1998,47(11):2274-2279
The stilbene complex of ytterbium (PhCH=CHPh)Yb(THF)2 (1) was prepared by the reaction of YbI2(THF)2 with a twofold excess of (PhCH=CHPh)− Li+. Based on the data of IR and ESR spectroscopy and on the results of magnetic measurements, compound1 was characterized as a complex of divalent ytterbium with the stilbene dianion. The reactivity of complex1 toward different types of reagents was studied. The structure of the product of the reaction of1 with 2,4,6-tri(tert-butyl)phenol (2,4,6-But
3C6H2O)2Yb(THF)3 was established by X-ray diffraction analysis.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2345–2350, November, 1998. 相似文献
105.
Chunping Gao Allan S. Hay 《Journal of polymer science. Part A, Polymer chemistry》1995,33(16):2731-2739
High molecular weight polymers from trans-4,4′-dihydroxystilbene, bisphenols, and 4,4′-difluorodiphenylsulfone were synthesized by a nucleophilic displacement reaction using DMAc as solvent in the presence of potassium carbonate. Characterization and crosslinking studies of these polymers were carried out by DSC, TGA, TMA, x-ray diffraction, and solution and solid NMR. It was found that all polymers can be crosslinked to some extent on heating to 350°C. We also studied the epoxidation of these polymers with hydrogen peroxide in the presence of methyltrioctylammonium tetrakis (diperoxotungsto) phosphate (3—) as the catalyst in a biphasic system. The epoxidized polymers are thermally cross-linkable. Very efficient crosslinking was obtained by heating the epoxidized polymers at 350°C under nitrogen. © 1995 John Wiley & Sons, Inc. 相似文献
106.
以2,5-二氰基对二甲苯为起始原料,通过NBS溴化,Abuzov和Horner反应合成了一种D-π-A型不对称有机双光子吸收材料的关键中间体2,5-二氰基-4-[(二乙氧基磷酰)甲基]-4′-(N,N-二苯基)氨基二苯乙烯,其结构经NMR,IR和MS表征。 相似文献
107.
Xiang Zhu ZHANG Ming Shu WU You HUANG Ru Yu CHEN 《中国化学快报》2006,17(6):765-768
Bisphosphonic acids and their ester derivatives, carbon analogues of inorganic pyrophos- phate, are the most important organophosphorus compounds and exhibit unique physical and chemical properties in interaction with the alkaline earth cations or heavy m… 相似文献
108.
Data concerning the initial steps in the reductive condensation of trichloromethylarenes with hydroxylamine or hydrazines in pyridine have been obtained. High yields of the products of the reductive condensation obtained even at equimolar ratios of trichloromethylarene with hydroxylamine or hydrazine as well as the formation of unusual products,i.e., 4-pyridylhydrazones of substituted benzaldehydes, have been interpreted as the result of the participation of pyridine in the reaction as a reductive agent.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1928–1931, November, 1993 相似文献
109.
Two types of ligands-biphenyl and stilbene derivatives, which can be labeled with Tc-99m for the diagnosis of Alzheimer‘ s disease (AD) have been synthesized successfully. The key steps in these two syntheses involved Suzuki reaction and Wittig reaction respectively. The new discovered debromination reaction may be expanded to the compounds with double or triple bond adjacent to the carbon atom bearing the bromine atoms. These types of syntheses provide a route to a series of biphenyl and stilbene derivatives that will benefit the search of new lmaging agents for AD. 相似文献
110.
A highly diastereoselective cascade reaction protocol has been developed for the synthesis of isoxazolidine derivatives utilizing aryl halides, O-homoallyl hydroxylamine and palladium(0) in a one-pot reaction. 相似文献