Synthesis and inhibitory activity of alkyl(hydroxyaryl)amines

The reaction of ω-(4-hydroxyaryl)haloalkanes with various nitrogen-containing agents afforded primary, secondary, and tertiary amino derivatives of 2,6-dialkylphenols. For the compounds synthesized, the reaction rate constants with peroxide radicals were measured for cumene and methyl oleate oxidation. The total inhibitory activity in the model reactions of thermal autooxidation of lard and hexadecane was studied. The rate constants of alkyl(hydroxylaryl)amines are the same as those of the corresponding alkylphenols, whereas the total inhibitory activity of some alkyl(hydroxylaryl)amines exceeds substantially that for alkylphenols. Dedicated to the memory of Academician N. N. Vorozhtsov on the 100th anniversary of his birth. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1107–1112, June, 2007.     

Synthesis and Antioxidant Properties of Unsymmetrical Sulfides Based on ω-(3,5-Di-tert-butyl-4-hydroxyphenyl)alkanethiols

Unsymmetrical sulfides were prepared by reactions of -(3,5-di-tert-butyl-4-hydroxyphenyl)alkanethiols with various alkyl halides, and their antioxidant activity with respect to thermal autooxidation of lard was studied in relation to their structure.     

Reactivity of thio (amino) derivatives of the ω-(4-hydroxyaryl)alkyl type in radical reactions

The enthalpies, activation energies, and rate constants of the reactions of thio (amino) alkylphenols of different structures were calculated and compared with those of the reactions of alkyl-substituted phenols, alkoxyl and alkyl radicals, hydroperoxides, and nitrogen dioxide, as well as the reactions of phenoxyl radicals with molecules of the substrate being oxidized. The calculation was performed by the intersecting parabolas method using O-H bond energy data for phenols. The correlation between the molecular structure of the thio (amino) alkylphenols and their reactivity in radical reactions is considered.     

Interrelation between the electrochemical activity of alkyl-and thioalkylphenols and their antioxidant action

The oxidation potentials of alkyl-and thioalkylphenols of various structures and the rate constants for their reactions with styrene peroxide radicals were determined. The overall inhibiting activity of the substances in a model reaction of the thermal autooxidation of lard was studied. The oxidation potential of phenols was found to correlate with the O-H bond energy, the rate constants for phenol reactions with styrene peroxide radicals and phenoxyl radical reactions with Tetralin molecules, and the effectiveness of the overall inhibiting action of these compounds.     

Synthesis and Antioxidative Properties of New Sulfur-Containing Derivatives of Sterically Hindered Phenols

3-(3,5-Di-tert-butyl-4-hydroxyphenyl)-1-chloropropane was converted into derivatives containing S(II) in various functional groups. The inhibiting power of the compounds with respect to thermal autooxidation of animal fat was evaluated.     

Synergistic Effects in SO-3 Antioxidant and Its Structural Analogs,as Compared to Trialkylphenol-Dialkyl Sulfide Mixtures

The inhibiting activity of SO-3 antioxidant and its structural analogs in the model reaction of autooxidation of Vaseline oil was compared to that of synergistic mixtures of 2,4,6-trialkylphenols and didodecyl sulfide.     

Relationship between the electrochemical and antioxidant activities of alkyl-substituted phenols

Oxidation potentials and rate constants have been determined for reactions between alkyl-substituted phenols with various structures and the styryl peroxy radical. The overall inhibiting activity of the phenols in the thermal autooxidation of lard has been studied. The interrelation between the structure, physicochemical properties, and antioxidant activity of the phenols is discussed.     

Synthesis and Antioxidant Properties of Bis[ω-(3,5-dialkyl-4-hydroxyphenyl)alkyl] Sulfides

The reaction of -(3,5-dialkyl-4-hydroxyphenyl)-1-chloroalkanes with sodium sulfide yielded the corresponding sulfides, which were tested as antioxidants in two model reactions: oxidation of lard and Vaseline oil.     

Synthesis and Antioxidative Activity of <Emphasis Type="Italic">N,N</Emphasis>-Dialkyl-ω-[4-hydroxy(methoxy)aryl]alkylamines and Their <Emphasis Type="Italic">N</Emphasis>-Oxides

Aminoalkylphenols of various structures were prepared by reactions of ω-[4-hydroxy(methoxy)aryl]haloalkanes with dialkylamines. The corresponding N-oxides were prepared by oxidation of aminoalkylphenols with hydrogen peroxide and cumene hydroperoxide. The inhibiting activities of these compounds in a model reaction of thermal autooxidation of lard were compared.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 5, 2005, pp. 796–801.Original Russian Text Copyright © 2005 by Dyubchenko, Nikulina, Terakh, Prosenko, Grigor’ev.     

Inhibiting Effect of Sulfur-Containing Alkylphenols on Oxidation of Vaseline Oil

A comparative study was made of antioxidative properties of sulfur-containing 2,6-di-tert-butylphenol derivatives in a model reaction of autooxidation of Vaseline oil.