Reaction of indole with N-acylimmonium salts in situ

The possibility of direct amidomethylation of indole and some other organic compounds with N-acylimmonium salts formed by reaction of azomethines with acylating agents was observed.See [1] for a preliminary communication.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 493–496, April, 1976.     

Identical acyl transfer reactions between pyridine N-oxides and their N-acylonium salts

28 identical acyl exchange reactions R-CO-Nu⁺, X^? + Nu between pyridine N-oxides in acetonitrile were studied. Here, X^? = BPh ₄ ^? and R = methyl, N,N-dimethylamino, N,N-diethylamino, 4-morpholino, 1-piperidino, N-methyl, N-phenylamino, or N,N-diphenylamino group. The IR and NMR spectroscopic characteristics of acyloxypyridinium salts were determined, and the quantum-chemical parameters of all reagents calculated. The results were subjected to correlation analysis. It was found that the rate of identical acyl transfer reactions was controlled by the interaction of frontier orbitals in the transition state.     

Effect of lower alcohols on adsorption characteristics of sodium dodecyl sulfate solutions at liquid-gas interfaces

The dynamics of a decrease in the surface tension is studied for aqueous solutions of sodium dodecyl sulfate and its mixtures with lower alcohols (ethanol and n-propanol). Two approaches are analyzed as applied to the estimation of the adsorption of two surfactants from their mixed solutions at a liquid—gas interface, i.e., the Frumkin generalized model and the Fainerman—Miller model. It is shown that both approaches adequately describe the concentration dependences experimentally measured for the surface tension of sodium dodecyl sulfate—lower alcohol mixtures.     

Study of reaction of gossypol and its imino derivatives with 2,2-diphenyl-1-picrylhydrazyl

Structures and state in solutions of natural polyphenol gossypol and four its imino derivatives, three of which were synthesized for the first time, were studied by IR and NMR spectroscopy, and by quantum chemistry. The reaction of these compounds with 2,2-diphenyl-1-picrylhydrazyl (DPPH) in ethanol was examined. The antioxidant activity of the studied compounds in the reaction with DPPH was evaluated using the values of the stoichiometric coefficients of reaction, EC₅₀, T ₁^2/DPPH and AE parameters. Gossypol hydrazones were shown to be 5–10 times more efficient, while Schiff base to be less efficient as antioxidants in comparison with gossypol itself. The influence of metal cations on the antioxidant activity of gossypol derivatives was studied.     

Fluorodensitometric determination of mangiferin and isomangiferin inHedysarum flavescens andH. alpinum

Summary A fluorodensitometric method has been proposed for determining mangiferin and isomangiferin inHedysarum flavescens andH. alpinum. The relative accuracy of the method for the raw material is ±4.8%.Khar'kov Scientific-Research Institute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 448–450, July–August, 1976.