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One-pot synthesis of 2-methylquinoxaline, 3-hydroxy-2-methylimidazo[1,2-a]pyridine, and 2-methyl-3,7-dihydroimidazo[1,2-a]pyrazin-3-one via cycloaddition of N,N-binucleophilic o-phenylenediamine, 2-aminopyridine, and 2-aminopyrazine, respectively, to methylglyoxal generated in situ by hydrolysis of 2-alkoxypropenals is reported for the first time. Thus 2-alkoxypropenals in weakly acidic medium (25–80°C, 1–4 h) are convenient synthetic equivalents of methylglyoxal in the synthesis of heterocyclic compounds. 相似文献
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Ekaterina A. Verochkina Nadezhda Victorovna Vchislo Igor B. Rozentsveig 《Molecules (Basel, Switzerland)》2021,26(14)
α-Functionalized α,β-unsaturated aldehydes is an important class of compounds, which are widely used in fine organic synthesis, biology, medicine and pharmacology, chemical industry, and agriculture. Some of the 2-substituted 2-alkenals are found to be the key metabolites in plant and animal cells. Therefore, the development of efficient methods for their synthesis attracts the attention of organic chemists. This review focusses on the recent advances in the synthesis of 2-functionally substituted 2-alkenals. The approaches to the preparation of α-alkyl α,β-unsaturated aldehydes are not included in this review. 相似文献
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N. A. Keiko T. A. Kuznetsova N. V. Vchislo Yu. A. Chuvashev L. I. Larina M. G. Voronkov 《Russian Journal of General Chemistry》2007,77(12):2145-2149
Synthetic procedures for preparing previously unknown 5-(1′-alkoxyethylidene)hydantoins from 2-alkoxy-1-cyano-1-trimethylsiloxy-1-(or -2-)propenes by one-pot successive reactions with ethanol and (NH4)2CO3 are developed. Some intermediates, reaction mechanism, and parameters determining the optimal yields are considered. Acid hydrolysis of ethylidenehydantoins occurs at the vinyloxy group and gives 5-acetylhydantoin in 64% yield. 相似文献
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N. A. Keiko N. V. Vchislo L. G. Stepanova L. I. Larina Yu. A. Chuvashev E. A. Funtikova 《Chemistry of Heterocyclic Compounds》2008,44(12):1466-1471
Condensation of 2-ethoxypropenal with diaminoethylene in different solvents (CHCl3, MeCN, H2O, DMSO) at room temperature gives an equilibrium mixture (1:1–1.5) of tautomeric 2-(1′-ethoxyvinyl)-1,3-imidazolidine and
2-aminoethylimine of 2-ethoxypropenal as well as 1,2-bis(2′-ethoxypropenyl-ideneamino)ethylene. The latter is readily prepared
in quantitative yield using a twofold excess of the aldehyde. 1H NMR was used to demonstrate the effect of heating on the dynamics of the ring-chain tautomeric equilibrium. Reaction of
the 2-alkoxypropenals with N-methyl- and N,N′-diphenyl-1,2-diaminoethylenes and with N-phenylaminoethanol gives only the corresponding
substituted imidazolidines in 43–95% yield.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov in his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1809–1815, December, 2008. 相似文献
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N. A. Keiko N. V. Vchislo L. I. Larina K. A. Chernyshev 《Russian Journal of General Chemistry》2012,82(1):77-81
Methods were proposed for the synthesis of the methylglyoxal 1,2-bis-(N,N-dimethylhydrazone). A possibility was shown for the first time of its participation in the Diels-Alder reaction with maleic
anhydride as an electron-rich diene. The second reaction of these reagents, which is observed in a wet media, is the formation
of the hydrazinium salt of the initial diene with maleic acid. The most probable structure of the protonated diene among the
four possible forms was revealed by the quantum-chemical calculations of the energy of the molecules and by the analysis of
the 13C NMR chemical shifts. 相似文献
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N. A. Keiko E. A. Funtikova N. V. Vchislo L. I. Larina Yu. L. Frolov 《Russian Journal of Organic Chemistry》2011,47(12):1832-1840
2-(1-Alkoxyvinyl)-1,3-thiazolidines reacted with H2O or D2O in the presence of 105 mol % of p-toluenesulfonic acid or trifluoroacetic acid (20°C, 1 h) to give 2-acetyl-1,3-thiazolidine in quantitative yield. 2-(1-Alkoxyvinyl)-3,5-diphenylimidazolidines
underwent hydrolysis in the presence of 20 mol % of an acid (20°C, 24 h) at the vinyloxy group with high regioselectivity
yielding 2-acetylimidazolidines. Hydrolysis of 2-(1-alkoxyvinyl)-3-phenyl-1,3-oxazolidines in the presence of 10 mol % of
p-toluenesulfonic acid (20°C, 5 days) takes two pathways, one of which involves the endocyclic C-O bond with ring opening and
the other involves the vinyloxy group to produce 2-acetyl-3-phenyl-1,3-oxazolidine. Unlike phenyl-substituted 1,3-thiazolidines
and imidazolidines, hydrolysis of their 3-methyl- and 3,5-dimethyl-substituted analogs in acid medium occurs mainly via ring
opening. The observed hydrolysis pathways were interpreted in terms of B3PW91/6-311G(d,p) quantum-chemical calculations. 相似文献
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Adamovich S. N. Ushakov I. A. Afonin A. V. Vchislo N. V. Oborina E. N. Pavlov D. V. 《Russian Chemical Bulletin》2021,70(2):406-411
Russian Chemical Bulletin - Silatranes bearing the aryl(hetaryl)-substituted 1-azadienyl moiety ((Het)ArCH=C(YR) C(H)=N- (Y = O, S)) were synthesized by the reaction of 1-(3-aminopropyl)silatrane... 相似文献
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