Synthesis and transformations of 1-(azidophenyl)-1H-tetrazoles

Diazotization of 1-(aminophenyl)-1H-tetrazoles and subsequent treatment of the diazonium salts with sodium azide gave 1-(azidophenyl)-1H-tetrazoles which were brought into cyclization with ethyl acetoacetate and cyanoacetanilide to obtain 1,2,3-triazole derivatives. Under these conditions, the tetrazole ring may undergo cleavage with formation of cyanamide group.     

One-pot synthesis of alkyl 3-aryl-2-(4-phenyl-1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazol-1-yl)propanoates

Reaction of 3-aryl-2-bromopropanoic acids esters, products of the Meerwein arylation, with sodium azide afforded alkyl 2-azido-3-arylpropanoates. The latter react with ethyl acetoacetate and phenylacetylene to form 1,2,3-triazole derivatives. A one-pot method for the synthesis of 3-aryl-2-(4-phenyl-1H-1,2,3-triazol-1-yl)-propanoic acid esters via a tricomponent reaction of alkyl 2-bromo-3-arylpropanoates, sodium azide, and phenylacetylene in the presence of CuI was developed.     

Thermodynamic properties of furan-2-carboxylic and 3-(2-furyl)-2-propenoic acids

The standard enthalpies of combustion, formation, fusion, and sublimation of crystalline furan-2-carboxylic and 3-(2-furyl)-2-propenoic acids are determined by experimental methods and recalculated to 298 K. The possibility of using additive calculation schemes based on the principle of group contributions to calculate the standard enthalpies of vaporization and formation of substances with similar combinations of functional fragments in the gas phase is analyzed.     

4-(4-Acethylphenyl)-3-hydroxycoumarin in the Synthesis of Nitrogen-containing Heterocycles with a Neoflavonoid Moiety

Russian Journal of Organic Chemistry - 4-(4-Acetylphenyl)-3-hydroxy-2H-chromen-2-one has been prepared by the reaction of (4-acetylbenzene)diazonium chloride with 3-hydroxy-2H-chromen-2-one under...     

Synthesis and reactions of 5-aryl-2-thiophenecarbaldehydes

The reaction of 2-thiophenecarbaldehyde with arene diazonium chlorides in the presence of CuCl₂ catalyst gave 5-aryl-2-thiophenecarbaldehydes. Use of 4-nitrobenzene diazonium chloride in the reaction also gave the isomeric 3-(4-nitrophenyl)-2-thiophenecarbaldehyde. Condensation products of the 5-aryl-2-thiophenecarbaldehydes with cyanoacetic acid esters, cyanoacetamide, and with barbituric and dimethylbarbituric acids were prepared. Communication 16 in the series “Synthesis of heterocycles based on the products of arylation of unsaturated compounds”. For Communication 15 see [1]. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1166–1171, August, 2008.     

Synthesis,nature of electronic transitions,and absorption spectra of the dye based on 4-(methyl-1-{2-[4-(1-methyl-2-oxo-1,2-dihydroquinolin-3-yl)phenyl]-2-oxoethyl}pyridinium bromide

The reaction of 3-(4-bromoacetylphenyl)-1-methylquinolin-2(1Н)-one with pyridine and 4-methylpyridine has afforded the corresponding pyridinium salts. Condensation of 4-methyl-1-{2-[4-(1-methyl-2-oxo-1,2-dihydroquinolin-3-yl)phenyl]-2-oxoethyl}pyridinium bromide with 4-dimethylaminobenzaldehyde has given a new biscyanine dye, 1-{1-[4-(1,2-dihydro-1-methyl-2-oxo-3-quinolinyl)benzoyl]-2-[4-(dimethylamino)-phenyl]ethynyl}-4-{2-[4-(dimethylamino)phenyl]ethynyl}pyridinium bromide. Its electronic spectrum has been analyzed, and quantum-chemical simulation of spatial and electronic structure of its possible isomers has been performed.     

Mechanism of Meerwein arylation of furan derivatives

Catalytic arylation of furan-2-carbaldehyde with arenediazonium salts was studied. The yields of 5-arylfuran-2-carbaldehydes were found to depend on the solvent, catalyst, and anion in the arenediazonium salt. Redox catalysis and generation of aryl radicals are not sufficient conditions for the reaction to occur. The reaction is successful only under conditions ensuring formation of complex intermediates. A mechanism involving two Cu²⁺ ? Cu⁺ catalytic series and generation of furan-2-carbaldehyde was proposed.     

Thermodynamic properties of 5(nitrophenyl) furan-2-carbaldehyde isomers

Background

The aim of the current work was to determine thermo dynamical properties of 5(2-nitro phenyl)-furan-2-carbaldehyde, 5(3-nitro phenyl)-furan-2-carbaldehyde and 5(4-nitro phenyl)-furan-2-carbaldehyde.

Results

The temperature dependence of saturated vapor pressure of 5(2-nitro phenyl)-furan-2-carbaldehyde, 5(3-nitro phenyl)-furan-2-carbaldehyde and 5(4-nitro phenyl)-furan-2-carbaldehyde was determined by Knudsen’s effusion method. The results are presented by the Clapeyron–Clausius equation in linear form, and via this form, the standard enthalpies, entropies and Gibbs energies of sublimation and evaporation of compounds were calculated at 298.15 K. The standard molar formation enthalpies of compounds in crystalline state at 298.15 K were determined indirectly by the corresponding standard molar combustion enthalpy, obtained using bomb calorimetry combustion.

Conclusions

Determination of the thermodynamic properties for these compounds may contribute to solving practical problems pertaining optimization processes of their synthesis, purification and application and it will also provide a more thorough insight regarding the theoretical knowledge of their nature.

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Graphical abstract: Generalized structural formula of investigated compounds and their formation enthalpy determination scheme in the gaseous state

     

Synthesis of 1H-1,2,3-triazole derivatives by the cyclization of aryl azides with 2-benzothiazolylacetonone, 1,3-benzo-thiazol-2-ylacetonitrile,and (4-aryl-1,3-thiazol-2-yl)acetonitriles

The cyclization of aryl azides with 2-benzothiazolylacetone, 1,3-benzothiazol-2-ylacetonitrile, and (4-aryl-1,3-thiazol-2-yl)acetonitriles in methanol in the presence of sodium methylate gives high yields of new products, 2-(5-methyl(amino)-1-aryl-1H-1,2,3-triazol-4-yl)-1,3-benzothiazoles and 1-aryl-(4-aryl-1,3-thiazol-2-yl)-1H-1,2,3-triazole-5-amines. 1,3-Benzothiazol-2-ylacetonitrile undergoes an anionic domino reaction with methyl 2-azidobenzoate or 2-azidobenzonitrile to give [1,2,3]triazolo[1,5-a]quinazoline derivatives. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 612–618, April, 2009.