Alevtina Yu. Yegorova

Reaction of 3-Arylmethylidene-3H-furan-2-ones with 3-Amino-1,2,4-triazole as a Convenient Technique to Synthesize Condensed Diazepinones

Abstract The interaction of the arylmethylidene derivatives of 3H-furan-2-ones with 3-amino-1,2,4-triazole was studied. The structure of the final products depends on reaction conditions and reagent ratio.

13C and 1H NMR study of azo coupling products from diazonium salts and furan-2-(3H)-ones

The heterocyclic compounds containing a hydrazone moiety in their structure are of considerable interest because of a variety of chemical reactions, whose products exhibit pronounced biological action. The design of preoperatively convenient, cost effective methods to synthesize functionally substituted heterocycles, having practically important properties, is always at the focus of researchers attention. Analysis of the literature leads to the conclusion that the method based on the use of unsubstituted 5-arylfuran-2-(3H)-ones in coupling reactions with diazonium salts is one of the most convenient to synthesize 5-aryl-3-arylhydrazonofuran-2-(3H)-ones. Previously, scientists from Egypt synthesized similar compounds. The authors studied the structure of hydrazones obtained using spectroscopic data analysis methods. The authors have proposed three possible tautomeric forms, and on the basis of elemental analysis and spectroscopicmethods have indicated formation of hydrazones furanone series. According to the authors, their stabilization is possible with the participation of the intramolecular hydrogen bond that is formed between the CO and NH groups. However, these data are insufficient to accurately determine the structure of the compounds studied. Therefore, on the basis of modernmethods of research, we have established the exact structure of hydrazones of furanone series.

Reaction of arylmethylidene derivatives of 3H-furan-2-ones with azomethine ylide

Previously unknown dispiropyrrolidines were synthesized by 1,3-dipolar cycloaddition of azomethine ylide to 3-arylmethylidene-3Н-furan-2-ones. The cycloaddition reaction was demonstrated to proceed diastereoselectively through an endo-transition state. Alternative transition states for the reaction are discussed.

Study of E/Z isomerization of (arylamino)methylidenefuran-2(3H)-ones by 1H, 13C, 15N spectroscopy and DFT calculations in different solvents: Study of E/Z isomerization of (arylamino)methylidenefuran-2(3H)-ones

The structure and configuration of the series of previously unknown arylaminomethylidenefuran‐2(3H)‐ones have been determined in solution by 1H, 13C, 15N nuclear magnetic resonance spectroscopy including two‐dimensional experiments such as 1H─1H COSY, dqCOSY, 1H─13C HSQC, 1H─13C HMBC. It was found that synthesized substances exist as an equilibrium mixture of E‐ and Z‐enamines in solution. It was established on the basis of density functional theory calculations that the exchange between the two push–pull enamines is a simple rotation around an exocyclic partial double bond that depends on the effect of the solvents. Copyright

Synthesis of Compounds of the Pyrimidine Series Based on the Reactions of 3-Arylmethylidenefuran-2(3H)-ones with N,N-Binucleophilic Reagents

The arylmethylidene derivatives of furan-2(3H)-ones are important building blocks for the synthesis of various heterocyclic compounds containing pyrimidine and pyridazine structural fragments, analogues of nitrogen-containing bases of pyrimidine series. In order to continue the development of constructing of molecules containing pyridine and pyridazine fragments, this article is devoted to the synthesis of new biologically active compounds with these moieties. The introduction of a heterocyclic chromenone fragment changes the previously observed 5-R-3-arylmethylidenefuran-2(3H)-ones route of reaction with guanidine carbonate and leads to 3-[(2-amino-4-(2-hydroxyphenyl)pyrimidin-5-yl)methylene]-5-phenylfuran-2(3H)-ones (2a–d). The structure of the reaction products depends on the nature of the aromatic substituent at the C-3 position of the furanone ring. The interaction of 5-aryl-3-arylmethylidenefuran-2(3H)-ones (1e–h) with thiourea in the basic medium leads to the isolation of 5-(2-oxo-2-phenylethyl)-6-aryl-2-thioxotetrahydropyrimidine-4(1H)-ones (3a–d), demonstrating pronounced plant-growth regulatory activity. Optimal conditions for all discussed processes were developed.

A Diastereoselective Synthesis of Dispiro[oxindole-cyclohexanone]pyrrolidines by 1,3-Dipolar Cycloaddition

For the first time, arylmethylidene cyclohexanones that are non-symmetrical due to the presence of peripheral substituents were studied in 1,3-dipolar cycloaddition reactions. It is shown that the interaction with the azomethine ylide generated from sarcosine proceeds regio- and diastereoselectively, with the participation of two non-equivalent parts of the dipolarophile. Also for the first time, β-amino ketones (Mannich bases) were used as dipolarophile equivalents of unsaturated ketones. It was found that cycloaddition occurs diastereoselectively at the generated center.

(E)-7-[(4-Nitrophenyl)diazenyl]-3a-(p-tolyl)-2,3,3a,4-tetrahydro-1H-benzo[d]pyrrolo[1,2-a]imidazol-1-one 0.58-dimethyl sulfoxide 0.42-acetonitrile solvate: crystal structure, Hirshfeld analysis and DFT estimation of the energy of intermolecular interactions

In the crystal structure of the title compound, C23H19N5O3·0.58C2H6OS·0.42C2H3N, prepared by the azo coupling of the 4-nitrophenyldiazonium salt with 3a-(p-tolyl)-2,3,3a,4-tetrahydro-1H-benzo[d]pyrrolo[1,2-a]imidazol-1-one, the azo molecules are linked by N—H⋯O hydrogen bonds into chains along the a-axis direction, and by the π–π interaction into [101] chains.