共查询到20条相似文献,搜索用时 15 毫秒
1.
B. F. Kukharev V. K. Stankevich E. Kh. Sadykov N. A. Lobanova G. R. Klimenko 《Russian Journal of Organic Chemistry》2007,43(12):1809-1812
Enamino ketones were synthesized in 97–99% yield by reactions of 4,5-dihydropyrazoles with 1,3-dicarbonyl compounds. 相似文献
2.
Prof. Fernanda Andreia Rosa Samara Mendes de Souza Melo Dr. Karlos Eduardo Pianoski Julia Poletto Mariellen Guilherme dos Santos Dr. Michael Jackson Vieira da Silva Dr. Danielle Lazarin-Bidóia Dr. Hélito Volpato Prof. Sidnei Moura Prof. Celso Vataru Nakamura 《ChemistryOpen》2021,10(10):931-938
A series of 60 4-aminomethyl 5-aryl-3-substituted isoxazoles were synthesized by an efficient method and evaluated in vitro against Leishmania amazonensis and Trypanosoma cruzi, protozoa that cause the neglected tropical diseases leishmaniasis and Chagas disease, respectively. Thirteen compounds exhibited a selective index greater than 10. The series of 3-N-acylhydrazone isoxazole derivatives bearing the bithiophene core exhibited the best antiparasitic effects. 相似文献
3.
T. Lóránd F. Aradi Á. Szöllösy G. Tóth T. Kónya 《Monatshefte für Chemie / Chemical Monthly》1996,127(8-9):971-977
Summary The acid and base catalyzed isomerization of some tricyclic 2-pyrazolines with N-Carbamoyl-,N-thiocarbamoyl-and N-phenyl substituents was investigated. Starting fromcis ortrans 3-H, 3a-H diastereomers, equilibrium mixtures ofcis andtrans diastereomers were prepared which were separated and subsequently studied by1H NMR and13C NMR spectroscopy. A mechanism for the isomerization of the pyrazolines is suggested, supported by a deuterium exchange at C-3a.
Isomerisierung von einigen substituierten 4,5-Dihydropyrazolen
Zusammenfassung Die Isomerisierung einiger tricyclischer 2-Pyrazoline mit N-Carbamoyl-, N-Thiocarbamoyl-und N-Phenyl-substituenten unter saurer und basischer Katalyse wurde untersucht. Ausgehend von dencis odertrans 3-H,3a-H-Diastereomeren wurdencis- undtrans Gleichgewichtsgemische gewonnen, die getrennt und durch1H- und13C-NMR-Spektroskopie untersucht wurden. Ein Mechanismus für die Isomerisierung von Pyrazolinen wird vorgeschlagen, der durch den Deuteriumaustausch in Position 3a-C unterstützt wird.相似文献
4.
E. I. Klimova E. A. Vazquez Lopez T. Klimova M. Martinez Garcia N. N. Meleshonkova L. Ruiz Ramirez 《Russian Journal of General Chemistry》2004,74(12):1830-1835
Monocyclic 3- and 5-ferrocenyl-4,5-dihydropyrazoles with a free NH group in the molecule react with acetylacetone to form the corresponding enaminocarbonyl compounds. The latter were isolated as a single isomer, presumably E. 3-Ferrocenyldihydropyrazoles and 5-ferrocenyl-3-(p-methoxyphenyl)-4,5-dihydropyrazole analogously react with acetoacetic ester. 5-Ferrocenyl-3-phenyl-, 3-(p-bromophenyl)-5-ferrocenyl, and 3,5-diferrocenyl-4,5-dihydropyrazoles react with acetoacetic ester to form acetoacetylpyrazolides.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 12, 2004, pp. 1942–1947.Original Russian Text Copyright © 2004 by E. Klimova, Vazquez Lopez, T. Klimova, Martinez Garcia, Meleshonkova, Ruiz Ramirez.This revised version was published online in April 2005 with a corrected cover date. 相似文献
5.
A. P. Molchanov A. V. Stepakov R. R. Kostikov 《Russian Journal of Organic Chemistry》2004,40(10):1512-1517
N-Nitroso-4,5-dihydropyrazoles obtained from ethyl(methyl) 5-aryl-4,6-dioxo-1,3a, 4,5,6,6a-hexahydropyrrolo[3,4-c]pyrazole-3-carboxylates and ethyl(methyl) 7-aryl-6,8-dioxo-1,2,7- triazaspiro[4.4]non-2-ene-3-carboxylates eliminate nitrogen molecule on heating to afford the corresponding 4,5-dihydroisoxazole derivatives.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, pp. 1561–1565.Original Russian Text Copyright © 2004 by Molchanov, Stepakov, Kostikov. 相似文献
6.
7.
8.
N. Rezki N. Rashed L. F. Awad E. Ramadan S. M. Abdel-Maggeed E. S. H. El Ashry 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1759-1767
Six new thioglycosides incorporating the 4,5-diphenyl- and 3,4,5-triphenylimidazole moiety have been successfully synthesized under both conventional and microwave conditions by reaction of the corresponding thiones with aceto-bromosugars in presence of triethylamine as base. Attempted preparation of the bis(glycosyl) derivatives from 4,5-diphenylimidazole-2-thione in the presence of different bases was unsuccessful. Evaluation of the glycosylthioimidazoles as disarmed donors has been investigated using different promoters; NBS/TMSOTf has been found to be an effective promoter for the activation of the anomeric center towards glycosylation reaction. 相似文献
9.
(S)-4,5-Difluoro-2-methylindoline (S)-11 was synthesized effectively by asymmetric reduction of N-[(R)-N-p-toIylsulfonyl]prolinyl-2-(2-oxo)propyl-3,4-difluoroanilide 4b followed by successive methylsulfonylation and intramolecular cyclization. 相似文献
10.
Abstract A new and a simple approach toward synthesis of 1,3,5-trisubstituted pyrazoles from chalcone arylhydrazones via oxidative cyclization has been achieved. 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone was successfully used as an oxidizing agent to give excellent yields of pyrazoles. 相似文献
11.
13.
The copper [I]-catalyzed exchange of bromine by methoxide in 5-bromovanillin and in 3,5-dibromo-4-hydroxybenzaldehyde provides an efficient method for preparing 3,5-dimethoxy-4-hydroxybenzaldehyde, from which 3,4,5-trimethoxybenzaldehyde is obtained by methylation with dimethylsulfate. 相似文献
14.
Synthesis of 3,4,5-trinitropyrazole 总被引:4,自引:0,他引:4
I. L. Dalinger G. P. Popova I. A. Vatsadze T. K. Shkineva S. A. Shevelev 《Russian Chemical Bulletin》2009,58(10):2185
A first representative of exhaustively C-nitrated pyrazoles was obtained by oxidation of 5-amino-3,4-dinitropyrazole. 相似文献
15.
Oleg I. Kolodiazhnyi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8-9):2111-2114
New examples of multistereoselective syntheses of organophosphorus compounds are described. 相似文献
16.
The conversion of cyclic Baylis–Hillman acetates 1 into the corresponding cyano derivatives 2 was achieved using potassium cyanide in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) in aqueous medium. The obtained Michael acceptors 2 easily add primary amines in absolute ethanol to produce a new family of 1,2,3-trisubstituted cyclpentanes 3 in good yields. 相似文献
17.
It is shown that sodium (methoxycarbonyl)cyclopentadienide ( 1 ), which is easily accessible from sodium cyclopentadienide and dimethyl carbonate in THF, reacts with 2,4,6-trisubstituted pyrylium tetrafluoroborates 2a–d in boiling MeOH to afford the corresponding methyl azulene-2-carboxylates 4a–d in good yields. The corresponding 1-carboxylates 3 were not found (cf. Schemes 1 and 2). 相似文献
18.
Mariola Zielinska-B?ajet 《Tetrahedron》2005,61(22):5235-5240
A new and simple method for the stereospecific synthesis of 3,5-disubstituted-4,5-dihydro-isoxazoles (chiral isoxazolines) from readily available oximes of chiral Michael adducts of thiophenol to chalcones is reported. An analogous reaction with the N-arylhydrazones of the Michael adduct gave nonracemic 1-(aryl)-3,5-diphenyl-4,5-dihydro-1H-pyrazoles (chiral pyrazolines), but these products are configurationally unstable. The key step of the synthesis is the ring-closure reaction, which occurs by a stereospecific intramoleculer nucleophilic substitution of thiophenoxide. 相似文献
19.
以没食子酸为原料。经烷基化、肼解得3,4,5-三甲氧基苯甲酰肼(2),2与芳香醛进行缩合反应合成了9个新的酰腙化合物。其结构经元素分析。IR,1H NMR和MS表征。 相似文献
20.
Introduction4 ,5 Dihydropyrazolederivativeshavebeenstudiedextensivelyduetotheirdiversechemicalreactivity ,broadspectrumofbiologicalactivityandvarietyofindustrialap plication .1Inaddition ,itisknownthat 4 ,5 dihydropyra zolederivativeswereusefulcompoundsnotonl… 相似文献