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Chebanov VA Muravyova EA Desenko SM Musatov VI Knyazeva IV Shishkina SV Shishkin OV Kappe CO 《Journal of combinatorial chemistry》2006,8(3):427-434
Multicomponent reactions (MCRs) and microwave-assisted organic synthesis (MAOS) have been used as key methods for the synthesis of fused dihydropyrimidine derivatives. The three-component condensation of 3-amino-5-alkylthio-1,2,4-triazoles with aromatic aldehydes and acetoacetamides under microwave irradiation was developed as a rapid and efficient solution-phase method for the high-yielding preparation of 7-aryl-2-alkylthio-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine-6-carboxamide libraries. In addition, the selective reduction of the formed dihydrotriazolopyrimidines to trans-trans-2-alkylthio-7-aryl-4,5,6,7-tetrahydro-1,2,4-triazolo[1,5-a]pyrimidine-6-carboxamides was established. The described synthetic protocols provide rapid access to novel and diversely substituted dihydroazolopyrimidine libraries. 相似文献
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Molecular and crystal structure of 5,7-diphenyl-7-methyl-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine
O. V. Shishkin N. V. Getmansky S. M. Desenko V. D. Orlov S. V. Lindeman Yu. T. Struchkov 《Russian Chemical Bulletin》1993,42(11):1827-1829
The molecular and crystal structures of 5,7-diphenyl-7-methyi-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine have been studied by X-ray structural methods. The crystal is monoclinic,a=16.112(3),b=13.489(3),c=14.480(3)Å, =101.62(2)°,Z=8, space groupC2/c,R=0.071. The presence of short intermolecular contacts indicates considerable steric strain in the molecule. The dihydropyrimidine ring exists in an unevenly planar boat conformation. Increasing the steric strain of the dihydrocycle leads to a twisted conformation.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1912–1914, November, 1993. 相似文献
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Sergey M. Desenko Sergey A. Komykhov Valery D. Orlov Herbert Meier 《Journal of heterocyclic chemistry》1998,35(4):989-990
The cyclocondensation of 6-acetyl-4,7-dihydro-5-methyl-7-phenyl[1,2,4]triazolo[1,5-a]pyrimidine (3) with hydroxylamine or hydrazine leads to 3a,4,9,9a-tetrahydro-3,9a-dimethyl-4-phenylisoxazolo-[5,4-d][1,2,4]triazolo[1,5-a]pyrimidine ( 4a ) and 3a,4,9,9a-tetrahydro-3,9a-dimethyl-4-phenyl-1H-pyrazolo[3,4-d][1,2,4]triazolo[1,5-a]pyrimidine ( 4b ), respectively. In the presence of methanolic hydrogen chloride, 4b undergoes a cleavage of the pyrimidine ring to yield (5-amino-1,2,4-triazol-1-yl)(3,5-dimethylpyrazol-4-yl)phenylmethane ( 5 ). The structure determination of the compounds obtained is based on 1H and 13C nmr spectra including NOE measurements. 相似文献
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A. M. Hussein S. M. Sherif A. A. Atalla 《Monatshefte für Chemie / Chemical Monthly》1996,127(11):1153-1160
Summary Condensation of cyano acid hydrazide1 with cyclopentanone in refluxing ethanolic piperidine yields hydrazone2. With mixtures of aliphatic aldehydes and different active methylene reagents,2 reacts to 1,2,4-triazolo[1,5-a]pyridines (8a–f). Compound2 also reacts with arylidenes9a–g to give triazolopyridines10a–g. Reaction of2 with aromatic aldehydes affords compounds13a–c. Diazotation of2 with aryldiazonium chloride in ethanol at 0 °C leads to the azo adducts15a–d. The thieno-1,2,4-triazolopyridine16 is obtained by reaction of8a with elementary sulfur.16 undergoes cycloaddition with -nitrostyrene, maleic anhydride, N-arylmalemide, and acrylonitrile yielding the isoquinolines21–24. All new compounds have been characterized by their IR,1H NMR, and mass spectra.
Ein neuer Syntheseweg für 1,2,4-Triazolo[1,5-a]pyridine und 1,2,4-Triazolo[1,5-a]isochinoline
Zusammenfassung Kondensation des Cyanohydrazids1 mit Cyclopentanon in ethanolischem Piperidin bei Rückflußtemperatur ergibt das Hydrazon2. Mit Gemischen aus aliphatischen Aldehyden und verschiedenen Verbindungen mit aktiven Methylengruppen reagiert2 zu 1,2,4-Triazolo[1,5-a]pyridinen (8a–f). Verbindung2 reagiert außerdem mit den Arylidenen9a–g zu den Triazolopyridinen10a–g. Umsetzung von2 mit aromatischen Aldehyden führt zu den Verbindungen13a–c. Diazotierung von2 mit Aryldiazoniumchloriden in Ethanol bei 0°C ergibt die Azoaddukte15a–d. Das Thieno-1,2,4-triazolylpyridin16 erhält man durch Reaktion von8a mit elementarem Schwefel.16 geht it -Nitrostyrol, Maleinsäureanhydrid, N-Arylmaleimid und Acrylnitril eine Cycloaddition zu den Isochinolinen21–24 ein. Alle neuen Verbindungen wurden durch ihre IR-,1H-NMR- und Massenspektren charakterisiert.相似文献
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S. M. Desenko V. D. Orlov V. V. Lipson O. V. Shishkin S. V. Lindeman Yu. T. Struchkov 《Chemistry of Heterocyclic Compounds》1991,27(11):1242-1246
5-Aryl-substituted 4,7(6,7)-dihydro-1,2,4-triazolo[1,5-a]pyrimidines were obtained by condensation of 3-amino-1,2,4-triazole with -dimethylaminopropiophenone hydrochlorides or crotophenone. The effect of steric and electronic factors on the position of the imine-enamine equilibrium in solutions of the synthesized substances is examined. 5-Phenyl-4,7-dihydro-1,2,4-triazolo[1,5-a]pyriniidine was subjected to x-ray diffraction analysis.See [1] for Communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1539–1544, November, 1991. 相似文献
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The 1,2,4-triazolo[1,5-a]pyrimidine-2-sulfonamides are a new class of highly active herbicides. A novel cyclization method for the synthesis of these compounds is discussed. 相似文献
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Gol Ravindra M. Khatri Taslimahemad T. Barot Vijaykumar M. 《Chemistry of Heterocyclic Compounds》2019,55(3):246-253
Chemistry of Heterocyclic Compounds - Efficient and regioselective on-water synthesis of variously substituted 5-amino-4,7-dihydropyrazolo[1,5-a]pyrimidine-6-carbonitriles and... 相似文献
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Gein V. L. Prudnikova A. N. Kurbatova A. A. Dmitriev M. V. 《Russian Journal of Organic Chemistry》2020,56(3):395-399
Russian Journal of Organic Chemistry - (7-Aryl-5-methyl-4,7-dihydrotetrazolo[1,5-a]pyrimidin-6-yl)(phenyl)methanones were synthesized by three-component condensation of 1-phenylbutane-1,3-dione... 相似文献
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Gein V. L. Gein L. F. Tsyplyakova E. P. Rozova E. A. 《Russian Journal of Organic Chemistry》2003,39(5):753-754
Russian Journal of Organic Chemistry - 相似文献
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N. N. Kolos V. D. Orlov B. V. Paponov O. V. Shishkin S. V. Baumer N. A. Kvashnitskaya 《Chemistry of Heterocyclic Compounds》1999,35(6):708-715
2,3-Diamino-5,7-diaryl-1,2,4-triazolo[1,5-a]pyrimidinium salts have been synthesized by the cyclocondensation of 3,4,5-triamino-1,2,4-triazole with 1,3-diaryl-2,3-propanes, and their structures and chemical properties have been studied.Kharkov State University, Kharkov 310077, Ukraine. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, 796–804 June, 1999. 相似文献
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3-Substituted 5-amino-1-guanyl-1,2,4-triazoles have been obtained which, on reaction with orthoformic ester or 100% formic acid, form 2-substituted 7-amino-1,2,4-triazolo[1,5-a]-[1,3,5]triazines. 相似文献
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S. M. Desenko O. V. Shishkin V. D. Orlov V. V. Lipson S. V. Lindeman Yu. T. Struchkov 《Chemistry of Heterocyclic Compounds》1994,30(7):851-855
Kharkov State University, 310077 Kharkov and Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 981–986, July, 1994.Original article submitted May 11, 1994. 相似文献