S. V. Bukharov

Synthesis of sterically hindered phenolic compounds from indole and its derivatives

Reactions of 3,5-di-tert-butyl-4-hydroxybenzyl acetate with indole and its derivatives gave a series of sterically hindered phenolic compounds having various functional groups. The products are potentially capable of inhibiting radical chain oxidation processes according to different mechanisms.

Crystal and Molecular Structure of 2,4,6-Tris(3,5-di-tert-butyl-4-hydroxybenzyl)resorcinol

The structure of 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)resorcinol in the crystal is virtually identical to that of 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)mesitylene, which is an effective antioxidant.

Antioxidant activity of isatin acylhydrazones with sterically hindered phenol fragments

Sterically hindered phenolic isatin acylhydrazones were found to possess high antioxidant activity in model reaction with a free chromogen-radical 2,2-diphenyl-1-picrylhydrazyl (DPPH).

Synthesis, structure and antioxidant activity of sulfur-containing tetrakisphenol

Abstract3-[2-(3,5-Di-tert-butyl-4-hydroxyphenylsulfanyl)acetoxy]2,2-bis[2-(3,5-di-tert-butyl-4-hydroxyphenylsulfanyl) acetoxymethyl]propyl 3,5-di-tert-butyl-4-hydroxyphenylsulfanylacetate was synthesized. Its structure was determined by means of 1H and 13C NMR spectroscopy and X-ray-diffraction analysis. This compound was found to possess high antioxidant activity in the conditions of auto-oxidation of low-pressure polyethylene.

Antiradical activity of benzazole-2-thiones

Reaction of benzoxazole-2-thione with 3,5-di-tert-butyl-4-hydroxybenzylacetate in methanol affords S-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-mercaptobenzoxazole as the major product. Antiradical activity of S- and N-3,5-di-tert-butyl-4-hydroxybenzyl derivatives of benzothiazole(oxazole, imidazole)-2-thione with respect to 2,2-diphenyl-1-picrylhydrazyl is varies widely. S-Benzyl derivatives exhibit higher reactivity at 30°C.

Synthesis of hydrazones containing sterically hindered phenol groups and tetrathiacalix[4]arene fragment

Abstract1,3-Alternate and cone stereoisomers of tetrathiacalix[4]arene and 4-tert-butyltetrathiacalix[4]arene functionalized by carbohydrazide groups reacted with 3,5-di-tert-butyl-4-hydroxybenzaldehyde to give the corresponding hydrazones having sterically hindered phenol fragments.

Synthesis of 3,5-di-tert-butyl-4-hydroxyphenylsulfanylmethyl-substituted tetramethylcalix[4]resorcinarenes

Dialkylaminomethyl-substituted calix[4]resorcinarenes have been reported long ago [1], but further transformations of these compounds were reported in a few publications [2–4], and the described transformations did not involve the dialkylaminomethyl group therein. An exception was the formation of the corresponding ammonium salts [5, 6] and thioamides [7]. Products of nucleophilic replacement of dialkylamino group in the above calix[4]resorcinarenes were not reported. On the other hand, deamination of phenolic Mannich bases is their typical reaction [8].

Synthesis of novel “hybrid” structures based on phosphorylacetic acid hydrazides and sterically hindered phenols

Abstract The insertion of fragments of sterically hindered phenols into the structure of phosphorylacetic acids hydrazides in their reactions with 3,5-di-tert-butyl-4-hydroxybenzylacetates and sterically hindered 2- and 4-hydroxybenzaldehydes has been carried out. The synthesis of 3,5-di-tert-butyl-4-benzyl derivatives of 5-[(diphenylphosphoryl) methyl]-2,4-dihydro-3H-1,2,4-triazol-3-thiones was also carried out. GRAPHICAL ABSTRACT

Synthesis and antioxidant activity of modified sterically hindered phenols

Salicylaldehyde derivatives containing sterically hindered phenol fragments were synthesized. The compounds obtained are capable to offer protection against UV radiation.

Synthesis and antioxidant activity of 3,5-di- tert -butyl-4-hydroxyphenylthiomethyltetraalkylcalix[4]resorcinarenes

Deamination of dimethyl- and diethylaminomethylated tetraalkylcalix[4]resorcinarenes with 3,5-di-tert-butyl-4-hydroxyphenylmercaptan afforded new 3,5-di-tert-butyl-4-hydroxyphenylthiomethyltetraalkylcalix-[4]resorcinarenes. High antioxidant activity of the synthesized alkylcalix[4]resorcinarenes was established in the model reaction of initiated oxidation of styrene.