Reaction of Tetramethylcalix[4]resorcinolarene with 3,5-Di-tert-butyl-4-hydroxybenzyl Acetate

Upper-rim modification of tetramethylcalix[4]resorcinolarene with 3,5-di-tert-butyl-4-hydroxybenzyl fragments is accompanied by unusual decomposition of the macroring in the modified product with formation of 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)resorcinol.     

Solvolysis of 3,5-Di-tert-butyl-4-hydroxybenzyl Acetate in Alcohol Solutions

Solvolysis of 3,5-di-tert-butyl-4-hydroxybenzyl acetate in alcohol solutions involves intermediate formation of 2,6-di-tert-butyl-4-methylene-1-benzoquinone that further takes up a molecule of the alcohol.     

New Opportunities for Duff Reaction

Reaction of 2,4-di-tert-butylphenol with urotropin in conditions of Duff reaction takes an abnormal route and instead of the expected di-tert-butylsalicylaldehyde provides a mixture of N-substituted 3,5-di-tert-butyl-2-hydroxybenzylamines and redox conjugate benzoxazines containing mostly 6,8-di-tert-butyl-3-(3,5-di-tert-butyl-2-hydroxybenzyl)-2H-3,4-dihydrobenz[e][1,3]oxazine. A solvolysis of an individual benzoxazine in the system HO(CH₂)₂OH-H₂O-HCl affords di(3,5-di-tert-butyl-2-hydroxybenzyl)amine, and in AcOH 3,5-di-tert-butylsalicilaldehyde. A mechanism of Duff reaction was suggested involving the formation of a benzoxazine intermediate.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 5, 2005, pp. 718–721.Original Russian Text Copyright © 2005 by Belostotskaya, Komissarova, Prokof’eva, Kurkovskaya, Vol’eva.     

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.     

2,6-Bis(3,5-di-tert-butyl-4-hydroxybenzyl)cycloalkanone: Synthesis and prospects for use as stabilizer for ethylene-propylene rubber

A phenolic antioxidant was synthesized by the reaction of N,N-dimethyl(3,5-di-tert-butyl-4-hydroxybenzyl) amine with cyclohexanone. The infl uence of temperature, reactant ratio, pressure, and time on the yield of the product, 2,6-bis(3,5-di-tert-butyl-4-hydroxybenzyl)cyclohexanone, was examined. The antioxidant obtained, taken both separately and in synergistic mixtures with alkylphenol and phosphites, showed high performance in inhibition of the thermal aging of ethylene-propylene rubber.     

Reactions of 3,5-di-tert-Butyl-4-hydroxybenzyl Acetate with Weakly Basic Nucleophiles

The acid dissociation of 3,5-di-tert-butyl-4-hydroxybenzyl acetate in the presence of bases or in dimethylformamide favors reaction of this compound with weakly basic nucleophilies.     

Calix[4]resorcinols as Stabilizers for Rubber Stocks Based on Butadiene-Acrylonitrile Rubbers

Modification of tetramethylcalix[4]resorcinol with dimethylaminomethyl and 3,5-di-tert-butyl-4-hydroxybenzyl fragments was studied. The antioxidative activity of these macrocyclic stabilizers in rubber stocks based on butadiene-acrylonitrile rubber was examined.     

Synthesis of new ordered aromatic polyester copolymers

Aromatic polyesters of 3,5-di-tert-butyl-4-hydroxybenzoic acid and 3,5-diisopropyl-4-hydroxybenzoic acid were prepared. The polymers were found to be high-melting but largely insoluble in organic solvents. The polymer based on 3,5-di-tert-butyl-4-hydroxy-benzoic acid was not degraded to monomer by sulfuric acid. A number of new aromatic polyesters were also prepared. Several new monomers for aromatic polyesters were synthesized, including bis(2,5-di-tert-butyl-4-carbophenoxyphenyl)terephthalate, m- and p-phenylene bis(3,5-di-tert-butyl-4-hydroxybenzoate), bis(2,6-di-tert-butyl-4-chlorocarboxyphenyl)terephthalate, and m-phenylene bis(3,5-diisopropyl-4-hydroxybenzoate). An aromatic polyester prepared from bis(2,6-di-tert-butyl-4-chlorocarboxyphenyl) terephthalate and resorcinol had a η_inh (trichloroethylene) of 1.05 (0.5%, 30°C) and a possible melting point of 330°C (DSC). Tough, creasable films could be cast from trichloroethylene solution of this polymer. Attempts to observe or to trap the keto-ketene that might result when 3,5-di-tert-butyl-4-hydroxybenzoyl chloride is treated with base were unsuccessful.     

Structure and intermolecular interactions of <Emphasis Type="Italic">N</Emphasis>-(3,5-di-<Emphasis Type="Italic">tert</Emphasis>-butyl-4-hydroxybenzyl)thioureas

The molecular and crystal structure and the hydrogen bonding in crystal and in solutions of N-phenyl-N-(3,5-di-tert-butyl-4-hydroxybenzyl)thiourea and N-(3,5-di-tert-butyl-4- hydroxybenzyl)thiourea were studied by single crystal X-ray diffraction and IR spectroscopy. The intermolecular interactions of these compounds are essentially different.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 11, 2004, pp. 1864–1870.Original Russian Text Copyright © 2004 by Bukharov, Litvinov, Gubaidullin, Chernova, Shagidullin, Nugumanova, Mukmeneva.This revised version was published online in April 2005 with a corrected cover date.     

Reactions of 4-acylresorcinol derivatives with 3,5-di-tert-butyl-4-hydroxybenzyl acetate

Reactions of hydroxyphenylcarbonyl derivatives with 3,5-di-tert-butyl-4-hydroxybenzyl acetate under mild conditions gave novel functionalized diarylmethanes. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1128–1133, July, 2006.     

Molecular structure of 2,4,6-tris(di-tert-butyl-4-hydroxybenzyl)resorcinol in the crystal and in solution, according to IR data

2,4,6-Tris(3,5-di-tert-butyl-4-hydroxybenzyl)resorcinol in the crystal and in solution has a similar steric structure, favorable for its performance as peroxyl radical scavenger.     

The Synthesis of (3,5-DI-tert-butyl-4-hydroxyphenyl)methyl-(3-pyridylalkyl)-ethers via 1-(3,5-Di-tert-butyl-4-hydroxyphenyl)methyl Pyridinium Salts.

The rearrangement of 1-(3,5-di-tert-butyl-4-hydroxyphenyl)methyl pyridinium salts under basic conditions is described. A method for the synthesis of (3,5-di-tert-butyl-4-hydroxyphenyl)methyl-(3-pyridylalkyl)-ethers is elaborated.     

Synthesis of novel phosphorus-containing sterically hindered phenols by the reaction of diphenyl (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methylphosphonate with phenols

Diphenyl (3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate was oxidized to the corresponding methylidenequinonoid derivative. The addition of phenols to the exocyclic double bond of this compound gave phosphonates with two phenol moieties.     

Synthesis,structure and antioxidant activity of sulfur-containing tetrakisphenol

3-[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.     

Reactions of benzazole-2-thiones with 3,5-di-<Emphasis Type="Italic">tert</Emphasis>-butyl-4-hydroxybenzyl acetate

The benzylation of benzothiazole(oxazole, imidazole)-2-thiones with 3,5-di-tert-butyl-4-hydroxybenzyl acetate involves either the sulfur or nitrogen atom depending on the reaction conditions. The S- and N-benzylation products of benzazole-2-thiones are kinetically and thermodynamically controlled products, respectively. The use of 3,5-di-tert-butyl-4-hydroxy-benzyl acetate allows sterically hindered hydroxybenzyl derivatives of benzаzole-2-thiones to be generally synthesized under milder conditions than in known methods of their synthesis.     

The structure and intermolecular interactions of N,N′-bis-(3,5-di-tert-butyl-4-hydroxybenzyl)urea

The molecular and crystal structure of N,N′-bis-(3,5-di-tert-butyl-4-hydroxybenzyl)urea has been established by single crystal X-ray diffraction and IR spectroscopy. There were also investigated intermolecular hydrogen bonds in its crystal and solutions.     

New Data on the Reaction of Diethyl Hydrogen Phosphite with 3,5-Di-tert-butyl-4-hydroxybenzaldehyde

3,3',5,5'-Tetra-tert-butylstilbene quinone and 1,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)-1,2-bis-(diethoxyphosphinoyl)-ethane were isolated from a mixture of products of the reaction of equivalent amounts of diethyl hydrogen phosphite and 3,5-di-tert-butyl-4-hydroxybenzaldehyde. A scheme of chemical transformations in this reaction system was offered.     

Synthesis and Chemical Transformations of β-(3,5-DI-tert-butyl-4-hydroxyphenyl)propionic Hydrazide

A method for synthesis of -(3,5-di-tert-butyl-4-hydroxyphenyl)propionic hydrazide. Certain chemical properties of the product were studied. It was found that -(3,5-di-tert-butyl-4-hydroxyphenyl) -(3,5-di-tert-butyl-4-hydroxyphenyl)hydrazide is highly susceptible to oxidation.     

Synthesis of 1,3-bis[(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)(dimethoxyphosphoryl)methyl]-4,6-dimethoxybenzene

A reaction of 1,3-dimethoxybenzene with dimethyl (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidenemethyl)phosphonate gave rise to 1,3-bis[(3,5-di-tert-butyl-4-hydroxyphenyl)-(dimethoxyphosphoryl)methyl]-4,6-dimethoxybenzene, which was oxidized to 1,3-bis[(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)(dimethoxyphosphoryl)methyl]-4,6-dimethoxy-benzene.     

Synthesis of sterically hindered phenol-containing phosphorylated isatin derivatives

Addition of isatin to the exocyclic double bond of dimethyl (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methylphosphonate gave dimethyl (3,5-di-tert-butyl-4-hydroxyphenyl)(2,3-dioxo-2,3-dihydro-1H-indol-1-yl)methylphosphonate. Its subsequent functionalization in reactions with thiosemicarbazide and 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionohydrazide yielded isatin derivatives containing several pharmacophoric fragments.