1,1,1-Trifluoro-3-(2-thenoyl)acetone in Reactions with Hydrazines

Properties of 1,1,1-trifluoro-3-(2-thenoyl)acetone and its reactions with hydrazine hydrate, 2,4-dinitrophenylhydrazine, and 1,1-dimethylhydrazone are studied.     

Esr and polarography of nitroazoles. 4. Polarographic study of nitrobenzimidazoles

The electrochemical reduction of 2-substituted 5(6)-benzimidazoles has been studied with the aid of classical polarography and cyclic voltammetry in acetonitrile. The influence of the substituents in position 2 on the magnitudes of the half-wave potentials of the first stage is exerted by induction and resonance mechanisms with approximately the same contributions, and that on the magnitudes of the half-wave potentials of the second stage predominantly by the resonance mechanism. The possibilities of taking the radical-stabilizing factor into account in the correlations are discussed. In order to study the 2-substituted 5(6)-nitrobenzimidazole series, their pK _a values in acetonitrile have been determined by potentiometric titration.For communication 3, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1246–1251, September, 1984.     

Spectroscopic Study of Reaction of Propargyl Bromide with Pyridine

Pyridine was reacted with propargyl bromide to obtain the dibromide [C₅H₅NCH = CHCH = CHCH = CHC₅H₅N]^{2 +} 2Br^-. The effect of the vinyl group on its UV spectrum is qualitatively interpreted using the results of nonempirical quantum-chemical calculations (basis HF/6-31G^*).     

EPR spectroscopy and polarography of nitroazoles. 3. Nitropyrazoles

The results of an EPR investigation are presented with polarographs of electrochemical excitation of nitropyrazoles in acetonitrile. It is shown that 3- and 4-nitropyrazoles are excited in two single-electron stages with formation of dianion radicals. Upon excitation, N-alkylnitropyrazoles form stable anion radicals. 1-Nitro- and 1,4-dinitropyrazoles are excited upon splitting off of the NO₂ anion. Excitation potentials of the nitropyrazoles and hyperfine interaction constants for the corresponding ion radicals are given.See [1] for Communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 523–527, April, 1982.     

IR spectroscopic study of substituent effects in N,N-dimethylhydrazides of aromatic acids

Conclusions An IR spectroscopic study showed that the C=0 values in the spectra of N,N-dimethylhydrazides of aromatic acids, RCONHN(Me)₂, correlate linearly with a regression equation obtained for the unsubstituted hydrazides of aromatic acids, RCONHNH₂. This dependence differs significantly from that for N-methyl-N-aroylhydrazines, in which ,-conjugation in the RC(O)N group is more pronounced.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2353–2355, October, 1987.     

19F NMR study of fluorinated mono- and diacylhydrazines

Conclusions It has been demonstrated by means of¹⁹F NMR that l-acyl-2-alkyl (phenyl) hydrazines are the main products of the monoacylation of alkyl- and phenylhydrazine with derivatives of perfluorocarboxylic acids. The preferred conformations with respect to the amide bond have been determined in mono- and di (perfluoroacyl) hydrazines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2735–2739, December, 1980.     

Synthesis and transformations of acids of the triazole series

3,5-Di(m- and p-tolyl)-1,2,4-triazples were obtained by reaction of formalin with 2,5-ditolyl-1,3,4-oxadiazoles and subsequent hydrolysis of the resulting formyl derivatives. 3,5-Di(o-tolyl)-1,2,4-triazole cannot be obtained by this method. The oxidation of 3,5-ditolyl-1,2,4-triazoles leads to 3,5-bis(carboxyphenyl)-1,2,4-triazoles, which were converted to diesters and dihydrazides.See [1] for communication III.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 848–849, June, 1978.