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1.
N. I. Golovanova D. -S. D. Toryashinova L. N. Sobenina M. P. Sergeeva A. I. Mikhaleva B. A. Trofimov 《Chemistry of Heterocyclic Compounds》1992,28(9):995-999
Research on the influence of substituenis on the reaction centers of molecules, through various bridge groups, is still an urgent task in theoretical organic chemistry. This problem is usually solved using the Hammett equation f= + a, by comparing the coefficient of the particular series of compounds under investigation with the coefficient
0 of a reference series of compounds. The ratio of coefficients /
0=, which is called the transmission factor, characterizes structural changes of the bridge group [1, 2].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, 1182–1186, September, 1992. 相似文献
2.
Ling Ke-Qing 《中国化学》1996,14(3):265-270
The title compound (1) was prepared via methylene blue (MB)-sensitized photooxy-genation of l-methyl-2-phenylindole (2d) in methanol. Acid-catalyzed nucleophilic substitution of 1 with nucleophiles gave 1,2,2-trisubstituted 3-oxo-2,3-dihydroindoles (3–6). Reduction of 1 with lithium aluminum hydride, followed by acidic workup yielded 4d and 2d, whereas the same reduction reaction of 1, followed by neutral workup gave l-methyl-2-phenyl-3-hydroxy-2,3-dihydroindole (15), together with 3. The reaction pathways of nucleophilic substitution and reduction of 1 were discussed. 相似文献
3.
正In our previous work,we found a new method by chance for the synthesis of thiazole derivatives with diversified substitutes on 2-and 5-positions of the thiazole scaffold which was published in Chinese Chemical Letters[2014,Vol.25 p.411].The structures were identified by ~1H NMR,~(13)C NMR and HRMS as 2-alkoxy-4-amino-Narylthiazole-5-carboxamides,exemplified by compound 4a(Fig.1).However,in our continuous research work,we found 相似文献
4.
Ya. A. Kastron G. A. Veinberg R. A. Gavar S. A. Hiller 《Chemistry of Heterocyclic Compounds》1968,2(6):657-661
It is found that 2, 4-dimethyl-5-nitrofuran-3-carboxylic acid and its methyl ester can give comparatively stable anionic groups, which are prepared electrochemically and investigated by EPR. Their lives (80–100 sec) are 4- 5 times greater than the lives of other anionic groups of the 5-nitrofuran series previously studied. Starting from 2, 4-dimethyl-5-nitrofuran-3-carboxylic acid and 2, 4-dimethylfuran-3-carboxylic acid, two new semisynthetic penicillins are prepared, with activities basically extending to Gram-positive microorganisms, including forms of staphylcocci resistant to benzylpenicillin. Introduction of the nitro group into the furan ring increases the stability of penicillin to acid 79-fold. Low toxicity penicillins are synthesized (LD50 1000–1500 mg/kg). 相似文献
5.
Hector Manuel Reyes-Rivera Robert O. Hutehins David R. Dalton 《Journal of heterocyclic chemistry》1995,32(2):665-669
A series of pyridine-2-carbaldoximes, all of which are substituted at the 4- or 5-position with derivatives of the corresponding carboxylic acids, have been prepared via the corresponding pyridine-2-carbaldehydes. 相似文献
6.
Ethyl 1-aryl-5-(trifluoromethyl)-1H-pyrazole-4-carboxylates 2 were prepared by the condensation of arylhydrazines with ethyl 3-ethoxy-2-(trifluoroacetyl)-2-propenoate (1a) at low temperature. The corresponding acids were also synthesized. X-ray diffraction analysis of an amide derivative 4 verified the position of the trifluoromethyl group on the pyrazole ring. 相似文献
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V. I. Potkin E. A. Dikusar A. V. Kletskov S. K. Petkevich E. A. Semenova I. A. Kolesnik T. D. Zvereva N. A. Zhukovskaya I. B. Rosentsveig G. G. Levkovskaya R. M. Zolotar 《Russian Journal of General Chemistry》2016,86(2):338-343
Acylation of alkyl- and 1,1′-dialkylferrocene alcohols and diols as well as (3,4,4-trichlorobut-3-ene-1-ol-1-yl)-4,5-cymantrene with dichloroisothiazole- and 5-arylisoxazole-3-carbonyl chlorides has afforded esters containing 1,2-azoles fragments. Some of the obtained compounds have exhibited potentiating action in the binary mixtures with insecticides. 相似文献
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Syntheses of Boc-protected 4-amino- and 5-amino-pyrrole-2-carboxylic acid methyl esters have been achieved and the structures of these compounds have been fully characterized by detailed NMR studies. 相似文献
12.
L. S. Kosolapova A. R. Kurbangalieva M. F. Valiev O. A. Lodochnikova E. A. Berdnikov G. A. Chmutova 《Russian Chemical Bulletin》2013,62(2):456-463
Reactions of 3-chloro-5-methoxy-4-[(4-methylphenyl)sulfanyl]-2(5H)-furanone with different nitrogen-containing binucleophilic agents were studied. The reaction with hydrazine monohydrate resulted in the formation of 1,5-dihydro-2H-pyrrol-2-one and pyridazin-3(2H)-one derivatives, whereas the reaction with phenylhydrazine led exclusively to 1-phenylamino-1,5-dihydro-2H-pyrrol-2-one. The reaction with ethylenediamine resulted in the isolation of 1,2-bis[2-oxo-1,5-dihydro-2H-pyrrol-1-yl]ethane: the enantiomeric dl-pair and two poly-morphic modifications of meso-form, which were characterized by X-ray crystallography. 相似文献
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Cross coupling protocols were applied for the synthesis of 3-(4-heteroaryl-phenyl)-8-oxabicyclo[3.2.1]oct-2-ene-2-carboxylic acid methyl esters. Stille conditions produced the corresponding products in reasonable yields. Samarium iodide reduction of the resulting coupling products produced the 2β-carbomethoxy-3α-aryl-8-oxabicyclo[3.2.1]octane diastereoisomers as the major, and the 2β-carbomethoxy-3β-aryl-8-oxabicyclo[3.2.1]octane diastereoisomer as the minor products. Both diastereomers manifested inhibition of the dopamine (DAT) and serotonin (SERT) transporters, with some selectivity for SERT inhibition. 相似文献
16.
Park YD Kim HK Kim JJ Cho SD Kim SK Shiro M Yoon YJ 《The Journal of organic chemistry》2003,68(23):9113-9115
N-Nitration of 4-chloro-5-substituted-pyridazin-3-one with copper nitrate trihydrate in acetic anhydride gave the corresponding 4-chloro-2-nitro-5-substituted-pyridazin-3-one. 4-Chloro-5-alkoxy-2-nitropyridazin-3-ones such as 5-methoxy (2b) and 5-ethoxy (2d) derivatives showed excellent nitro group transfer potentiality. N-Nitration of some secondary amines with 2b gave the corresponding N-nitramines under mild neutral condition in good yields. 相似文献
17.
1 INTRODUCTION3methyl4hydroxybenzofuranisanintermediateusedforthesynthesisofnatureproducts[1].Ithasbeensynthesizedfrom1,3dihydroxybenzene[2-3].Tosynthesizeabietanequinonediterpenoidswithit[4,5],weintendedtoprotectthehydroxyattachedtoitwithMe2SO4.Finally,twocompou… 相似文献
18.
John Nicolson Low Antonio Marchal Manuel Nogueras Manuel Melguizo Adolfo Sánchez 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(2):178-179
The title compound, C15H21N5O2, lies on a crystallographic mirror plane and is hydrogen bonded to neighbouring molecules by infinite chains formed by combinations of strong N—H⃛N and soft C—H⃛O hydrogen bonds. The pyrimidine moiety shows extensive delocalization. 相似文献
19.
在THF溶液中合成了标题化合物3-氯-4-二苄胺基-5-甲氧基-2(5H)-呋喃酮,并用FT-IR、UV-Vis、1HNMR、13C NMR、MS、元素分析和X-射线衍射等进行了表征。结果表明此化合物属正交晶系,空间群为Pbca,晶胞参数为:a=15.891(16),b=11.126(11),c=19.778(19),α=β=γ=90°,V=3497(6)3,Z=8,Dc=1.306Mg/m3,μ=0.234 mm-1,F(000)=1440。在化合物的分子结构中,两个苯环几乎垂直于呋喃酮平面,且它们与呋喃酮平面的两面角分别为89.38°和88.19°。 相似文献
20.
Gui-Xiang Sun Chiaki Kakei Etsuo Kume Toshihide Hatsui Seiji Ujiie Akira Mori 《Liquid crystals》2007,34(8):927-934
Troponoid esters and amides connected with cholest-5-ene-3β-carboxylic acid have been synthesized to characterize their mesomorphic properties and to compare them with those of the corresponding benzenoids. 5-Alkoxytroponyl esters and amides with a long alkoxy group exhibited a twist grain boundary A* phase, as well as chiral nematic and smectic A* (SmA*) phases. The corresponding benzenoid esters exhibit SmA* and blue phases and the benzenoid amides only a SmA* phase. The differences between the mesomorphic properties are discussed in terms of the structural features of the core. 相似文献