共查询到20条相似文献,搜索用时 15 毫秒
1.
Burkhardt I. Wilke 《Tetrahedron letters》2010,51(52):6871-6873
Derivatives of camphorsultam which contain novel spirooxazolidine and spirooxazine structures have been prepared in high yield and purity. Though it was expected that the ketone moiety would undergo acetal formation, the imine instead underwent reaction and was proven by X-ray crystallography and 2D NMR techniques. The initial ketone-containing derivatives were then reduced to produce exo-hydroxy analogs that have potential as a new family of chiral auxiliaries. 相似文献
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Dermot Twomey 《Journal of heterocyclic chemistry》1986,23(2):615-620
3-Amino-10-aryl-2-arylimino-2,10-dihydrophenazines 1 undergo iodination in the 4-position of the phenazine nucleus yielding compounds which are identical with those obtained by oxidation of appropriate N-aryl-o-phenylenediamines with sodium iodate in the presence of acid. Bromination also takes place in this position but a second bromine atom enters the para-position of the arylimino moiety. The isomeric 10-aryl-3-aryl-amino-2,10-dihydro-2-iminophenazines 2 yield unstable iodo-derivatives but undergo bromination in the 1-and 4-position of the phenazine nucléus and in the ortho- and para-positions of the arylamino substituent. Preliminary chlorination experiments indicate that the substitution pattern is analogous to that established for the brominated products. The removal of bromine and iodine from the phenazine ring by reaction with a primary or secondary amine and their replacement by hydrogen rather than by the amine residue is also recorded. 相似文献
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Hubert Hřebabecký Milan Dejmek Martin Dračínský Michal Šála Pieter Leyssen Johan Neyts Martina Kaniaková Jan Krůšek Radim Nencka 《Tetrahedron》2012,68(4):1286-1298
Azanorbornylpurine derivatives were prepared by Mitsunobu reaction of appropriate hydroxyazanorbornane derivative with 6-chloropurine or construction of purine base at azanorbornylamines. The prepared target compounds were evaluated for antiviral activity and effect on neuronal and muscle nicotinic acetylcholine receptors. 相似文献
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Bernard Bonnaud Dennis Bigg Jean-Franois Patoiseau 《Journal of heterocyclic chemistry》1991,28(8):1927-1932
The reaction of a number of γ-butyrolactones with azole anions is shown to give γ-substituted butanoic acids in moderate to good yields. The pyrrolyl and indolylbutanoic acids obtained underwent cyclization in a simple one-pot procedure employing ethyl chloroformate and boron trifluoride etherate. Some aspects of the chemistry of the resulting indolizin-8-ones are described. 相似文献
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Hubert Hřebabecký Milan Dejmek Michal Šála Helena Mertlíková-Kaiserová Martin Dračínský Pieter Leyssen Johan Neyts Radim Nencka 《Tetrahedron》2012,68(15):3195-3204
The synthesis and antiviral evaluation of 6-amino- and 6-chloro-9-(exo-bicyclo[2.2.1]hept-2yl)-9H-purine derivatives with thiophene and tetrahydrothiophenes annelated to a norbornane moiety are described. The key step in the synthesis of derivatives with the symmetrically annelated thiophene was the Mitsunobu reaction of endo-4-thiatricyclo[5.2.1.02,6]deca-2,5-dien-8-ol with 6-chloropurine. The key alcohol was obtained by DDQ mediated aromatization of the corresponding tetrahydro derivatives, which were used for the preparation of the target tetrahydrothieno analogs. The key intermediate for the synthesis of derivatives with the asymmetrically annelated thiophene was 8-exo-azido-3-thiatricyclo[5.2.1.02,6]deca-2(6),4-diene, which was prepared from 5-exo-azido[2.2.1]heptan-2-one by aldol condensation with O-ethyl S-(2-oxoethyl) carbonodithioate, deprotection and cyclization. The target compounds were obtained by the construction of the purine base on an amine, which was obtained by LAH reduction of the key azide. The synthesized compounds were evaluated for antiviral and cytostatic activity. 相似文献
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The design and synthesis of derivatives of 4-hydroxy-Tamoxifen as potential antagonists of the nuclear receptor LRH-1 are described. Stereoselective McMurry coupling was used to generate the desired internal alkene and a novel method for the synthesis of tetrasubstituted cyclopropane analogues was also developed. 相似文献
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Xiang Shi Hongxin Shi Hongke Wu HaiMin Shen 《Research on Chemical Intermediates》2018,44(9):5091-5105
A series of novel fluoroether-containing monomers has been designed and prepared based on the commercially available perfluoroalkyl ether acid fluoride. Treating acid fluoride with allyl alcohol, 2-hydroxyethyl methacrylate or N-allylmethylamine allowed for the direct formation of corresponding vinyl-containing fluorinated monomers. High yields of the fluorinated epoxy monomers could be obtained from acid chloride with glycidol; meanwhile, fluorinated diol was prepared from diethanolamine or 3-amino-1,2-propanediol. Moreover, fluorinated monoamine, fluorinated monoalcohol and fluorinated dichloride were also obtained. Most of these fluorinated monomers were liquid at room temperature and exhibited good solubility in common organic solvents. 相似文献
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Tamaki M Harada T Fujinuma K Takanashi K Shindo M Kimura M Uchida Y 《Chemical & pharmaceutical bulletin》2012,60(6):743-746
To find candidates with high antimicrobial and low hemolytic activities, many gratisin (GR) analogues have been designed and synthesized. In the present account, we synthesized novel derivatives of GR having both the polycationic and fatty acyl groups, cyclo{-Val(1)-Orn(2)-Leu(3)-D-Phe(4)-Pro(5)-D-Lys(6)(X)-Val(7)-Orn(8)-Leu(9)-D-Phe(10)-Pro(11)-D-Lys(12)-} {X=-CO(CH(2))(6)CH(3) (1), -Lys-CO(CH(2))(6)CH(3) (2), -(Lys)(2)-CO(CH(2))(6)CH(3) (3), and -(Lys)(3)-CO(CH(2))(6)CH(3) (4)}, and examined the biological activities. Among them, we found that 2-4 have differential ionic interaction against the prokaryotic membrane and eukaryotic membrane. In other words, the dissociation with high antimicrobial activity and low hemolytic activity is caused by the addition of D-Lys(6)-{(Lys)(n)-CO(CH(2))(6)CH(3)} residues at position 6 of [D-Lys(6,12)]-GR. Our findings should be helpful in finding drug candidates with high antimicrobial activity and low hemolytic activity that are capable of combating microbial resistance. 相似文献
11.
Teresa M.V.D. Pinho e Melo Catarina I.A. SantosAntónio M.d'A. Rocha Gonsalves José A. PaixãoAna M. Beja Manuela Ramos Silva 《Tetrahedron letters》2003,44(45):8285-8287
Novel 3-methylene-2,5-dioxo-3H,9bH-oxazolo[2,3-a]isoindoles were prepared from the thermolysis of (3R,9bS)-5-oxo-2,3,5,9b-tetrahydrothiazolo[2,3-a]isoindole-3-carboxylic acids in acetic anhydride. The structure of 3-methylene-2,5-dioxo-3H,9bH-oxazolo[2,3-a]isoindole 6a was determined by X-ray crystallography. 相似文献
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Shahin Kalantari Mohammad Piltan Seyed Amir Zarei 《Journal of the Iranian Chemical Society》2016,13(4):743-746
The zwitterion derived from quinoline and dialkylacetylenedicarboxylates on reaction with C–H acids such as: dialkylchloromalonates, and 3-chloro acetyl acetone afforded pyrroloquinoline derivatives in moderate yields (44–55 %). 相似文献
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Four novel dansyl-labeled derivatives of Celecoxib, a cyclooxygenase-2 (COX-2) selective inhibitor, were designed and synthesized. To realize the fluorophore-linker-approach divergent and convergent synthetic strategies were applied. Therefore Celecoxib p-benzoic acid, 8, was synthesized in a new and convenient way. The yield and the synthetic route to Celecoxib, 1, its pyrazolylic acid, 7, and its pyrazolylic methyl ester, 6, were improved. Through a convenient synthesis 1,11-diamino-3,6,9-trioxundecane, 19, was obtained in high yield and purity and used as a linker for the dansyl moiety. 相似文献
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Treatment of 6-amino-5-arylazo-1,3-dimethyluracils with ethyl propiolate gave the corresponding Michael-type adducts, 5-arylazo-1,3-dimethyl-6-ethoxycarbonylvinylaminouracils, which on treatment with a mixture of hydrochloric acid and acetic acid caused the acid-catalyzed rearrangement accompanied with rearrangement to give rise to the corresponding 8-anilinomethyltheophylline derivatives. In the case that the arylazo group possesses an electron-releasing substituent such as methoxy, the reaction proceeded in a different way to afford 1,2-bis(theophyllin-8-yl)ethane. The presumable reaction mechanisms for the above purine syntheses were proposed. 相似文献
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A. M. Fahmy M. Z. A. Badr Y. S. Mohamed F. F. Abdel-Latif 《Journal of heterocyclic chemistry》1984,21(4):1233-1235
Condensation of ethyl 2-(2-oxo-2,3-dihydro-1H-indolid-3-ene)cyanoacetate and/or 2-(2-oxo-2,3-dihydro-1H-indolid-2-ene)malononitrile with 3-methylpyrazolin-5-one, 1-phenyl-3-methyl-pyrazolin-5-one, benzoyl acetonitrile or ethyl acetoacetate affords different substituted quinolines. The reaction is suggested to proceed through a nucleophilic addition followed by ring opening and recyclization steps. 相似文献
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The chemical behaviors of 3-ethynylcoumarin towards benzyl bromide,diazonium chic ride,hydrogen chloride,ethyl magnesium bromide and its self-coupling are reported. 相似文献
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An efficient synthesis of novel 5-(4-nitrophenyl)-2-benzoxazol-2-yl-c-hetero-fused thiophenes was achieved by the condensation of 5-(4-nitrophenyl)-2-benzoxazol-2-yl-3,4-dichlorothiophene with ethylene glycol, ethylenediamine, substituted thioamides and 2-mercaptobenzimidazole using sodium carbonate in refluxing dimethyl formamide. 相似文献
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Young-Won Chin 《Tetrahedron letters》2004,45(2):339-341
Four novel lignans were isolated from the rhizomes of Rodgersia podophylla. It is interesting to note that an unusual 2,4-dihydroxyphenyl moiety was found in these compounds in addition to an acetylenic functionality in compounds 3 and 4. 相似文献
20.
Four new insecticidal sesquiterpene polyol esters with a beta-dihydroagarofuran sesquiterpene skeleton, celangulatin C (1), celangulatin D (2), celangulatin E (3), and celangulatin F (4), and five known compounds 5-9 were isolated from the low-polar toluene extracts of the root bark of Celastrus angulatus by bioassay-guided fractionation. Their chemical structures were elucidated mainly by analyses of MS and NMR spectral data. Celangulatin C, E and F showed LD(50) against Mythimna separata were 280.4, 1656.4 and 210.5 microg mL(-1), respectively. 相似文献