- MECHANISM OF THE ALKYLATION OF 2,6-DI-tert-BUTYLPHENOL BY METHYL ACRYLATE IN THE PRESENCE OF POTASSIUM 2,6-DI-tert-BUTYLPHENOXIDE AND ALKALI
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A mechanism is proposed for the reaction of 2,6-di-tert-butylphenol with methyl acrylate in the presence of potassium 2,6-di-tert-butylphenoxide and KOH and, based on a computer calculation of the kinetic scheme, the constants have been found for the elementary stages of the reaction, sufficient to interpret the experimental data.The alkylation of 2,6-di-tert-butylphenol by methyl acrylate takes place by an inhibited catalytic chain mechanism involving the participation of ion pairs in the reaction.
- Volod'kin, A. A.,Zaitsev, A. S.,Rubailo, V. L.,Belyakov, V. A.,Zaikov, G. E.
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- Alkylation of 2,6-di-tert-butylphenol with methyl acrylate catalyzed by potassium 2,6-di-tert-butylphenoxide
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The kinetics of catalytic alkylation of 2,6-di-tert-butylphenol (ArOH) with methyl acrylate (MA) in the presence of potassium 2,6-di-tert-butylphenoxide (ArOK) depends on the method for the preparation of ArOK. The reaction of ArOH with KOH at temperatures > 180 °C affords monomeric ArOK, whose properties differ from those in the case of potassium 2,6-di-tert-butylphenoxide synthesized by the earlier methods. The regularities of ArOH alkylation depend on the ArOK concentration, the ArOH: MA ratio, and the effect of microadditives of polar solvents.
- Volod'kin,Zaikov
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- Synthesis process of special intermediate for phenolic antioxidants
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The invention discloses a synthesis process of a special intermediate for phenolic antioxidants. The intermediate is methyl 3, 5-di-tert-butyl-4-hydroxyphenyl propionate. The synthesis process comprises the following steps: adding 2, 6-di-tert-butylphenol and a catalyst into a reactor, starting stirring and heating, controlling the temperature at 100-110 DEG C, and reacting for 0.5 h; dropwise adding a certain amount of methyl acrylate, controlling the temperature at 115-120 DEG C after drop-by-drop adding, and reacting for 1 hour; cooling to 80 DEG C, and filtering; and taking the filtrate for distillation, starting distillation, controlling the temperature to be 220-230 DEG C and the vacuum degree to be -0.095 Mpa, and obtaining the 3, 5-methyl ester after all the 3, 5-methyl ester is distilled off. The process provided by the invention has the advantages of high product purity, high yield, small pollution, short production period, energy consumption saving, simple production process and easy process control.
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Paragraph 0029-0036
(2021/08/11)
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- Method for preparing antioxidant 3,5-methyl ester
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The invention discloses a method for preparing an antioxidant 3,5-methyl ester. The method comprises the following steps: preparation of a catalyst, and preparation of the antioxidant 3,5-methyl ester. Methyl p-hydroxyphenylpropionate used as a raw material and tert-butanol undergo an alkylation reaction under a microwave condition under the action of the catalyst to obtain the antioxidant 3,5-methyl ester. Commonly-available and cheap clay is used as a raw material to prepare the novel catalyst, so waste of the catalyst is avoided, and the catalyst can be repeatedly used; and the methyl p-hydroxyphenylpropionate and tert-butanol are used as raw materials, so self-polymerization side reactions of the raw materials are avoided, and the prepared antioxidant 3,5-methyl ester has a high yieldand an excellent quality.
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Page/Page column 0022-0075
(2019/10/01)
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- Synthesis process of antioxidant 1076
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The invention provides a method of organically synthesizing an antioxidant 1076, i.e. octadecyl 3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate. The preparation method comprises the following steps: bytaking a mixed solution of ethylene glycol and methylbenzene as a solvent, and by taking methyl 3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate and stearyl alcohol as reactants, adding a catalyst andreacting to obtain the octadecyl 3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate. According to the preparation method, the mixed solution is used as the solvent, and the catalyst is added in batches ina reaction process, so that the organic synthesis method provided by the invention has the advantages that in the reaction of preparing the octadecyl 3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate, the use amount of the catalyst is less, the reaction temperature is low, the obtained product is high in purity, and the yield is still up to 92 percent or above in pilot scale test.
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Paragraph 0046-0049
(2018/09/08)
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- A singlet oxygen approach to oxaspirocycles
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A method for the preparation of oxygen containing spirocycles using singlet oxygen is reported. A series of phenols were converted into the corresponding peroxy-cyclohexadienone derivatives by irradiation with visible light in the presence of a sensitizer and oxygen. The resulting peroxides could be converted into ether and lactone spirocycles in one or two steps. The synthesis of the oxaspirocycles from the phenols can also be performed in a one-pot fashion, avoiding the isolation of the peroxide intermediates.
- Jones, Kevin M.,Hillringhaus, Tim,Klussmann, Martin
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supporting information
p. 3294 - 3297
(2013/06/27)
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- Transesterification of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate with tetrakis(hydroxymethyl)methane. the properties of the reaction products
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The transesterification of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate with tetrakis(hydroxymethyl)methane depends on the equilibrium constants of the reversible reactions; for the final step, the equilibrium constant is K 1. The molecular geometries and the enthalpies and entropies of the equilibrium reactions were calculated by the semiempirical PM6 quantum chemical method. The thermodynamic equilibrium constants of the reversible reactions were calculated by the Boltzmann equation from the Gibbs energies G f ○. For tris-[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoyloxymethyl](hydroxymethyl)methane, the dipole moment is μ = 0.97 D and the energy of the O-H homolysis is D OH = 347.3 kJ mol -1. For tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoyloxymethyl]methane, μ is 5.6 D and D OH is 321 kJ mol -1. The geometry of the structure affects the H-O homolysis energy and the chain termination coefficient under the conditions of inhibited cumene oxidation.
- Volod'Kin,Zaikov,Evteeva
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p. 1689 - 1693
(2013/11/19)
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- Interaction of functionally-substituted 4-alkyl-2,6-di-tert-butylphenols with hydrohalic acids
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Reactions of 4-alkyl-2,6-di-tert-butylphenols containing OH, SH, COOH, and COOMe groups in their para substituents with hydrogen chloride and hydrohalic acids were studied. One-step transformations of 2,6-di-tert-butyl-4-(ω- hydroxyalkyl)phenols to the corresponding 4-(ω-halogenoalkyl)phenols, as well as of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and its esters to phloretic acid were proposed. 4-(3-Mercaptopropyl)phenol upon heating with conc. HBr undergoes condensation to 3-(4-hydroxyphenyl)propyl 4-(3-mercaptopropyl)phenyl sulfide as the main product.
- Prosenko,Skorobogatov,Dyubchenko,Pinko,Kandalintseva,Shakirov,Pokrovsky
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p. 1119 - 1124
(2008/09/18)
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- CONTINUOUS PROCESS FOR THE PREPARATION OF HINDERED, ESTER-SUBSTITUTED PHENOLS
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The present invention related to a novel continuous process for the manufacture of hindered, ester-substituted phenols using 2,6-dialkylphenol a basic catalyst and acrylate esters.
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Page/Page column 10
(2010/11/28)
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- Processing improvements for hindered, ester-substituted phenols
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The present invention related to a novel continuous process for the manufacture of hindered, ester-substituted phenols using 2,6-dialkylphenol a basic catalyst and acrylate esters.
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Page/Page column 4
(2008/06/13)
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- Preparation of sterically hindered hydroxyphenylcarboxylic acid esters
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A novel manufacturing process is described for producing hindered phenolic alkyl esters, which may be useful as antioxidants. This process simplifies catalyst neutralization and removal during the preparation of hindered phenolic esters. Compositions that comprise the hindered phenolic esters produced according to these methods are also described.
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Page/Page column 14
(2010/02/13)
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- Formation and properties of a catalyst based on sodium and potassium hydroxides in the reaction of 2,6-di-tert-butylphenol with methyl acrylate
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The nature of the cation (K+ or Na+) in hydroxides affects the temperature plot of the equilibrium constant of the reaction of KOH and NaOH with 2,6-di-tert-butylphenol (ArOH) and the conversion of KOH and (or) NaOH to potassium or sodium 2,6-di-tert-butyl phenoxides, which are catalysts for the alkylation of ArOH by methyl acrylate. The kinetic method for determination of the composition of the catalyst formed from NaOH and ArOH was proposed. The nature of the cation in phenoxides ArOK or ArONa is a factor determining the kinetics of the reaction of ArOH with methyl acrylate. Two different kinetic schemes were proposed to describe the transformation of ArOH in the presence of ArONa or ArOK.
- Volod'kin,Zaikov
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p. 2189 - 2195
(2007/10/03)
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- Radical Chain Addition of Aryloxyl Radicals to Electron-deficient Alkeanes
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Michael addition of aryloxyl radicals to electron-deficient alkenes in the presence of Ag+ is described.
- Baik, Woonphil,Min, Byeong Cheol,Lee, Ki Chang,Jun, Young Moo,Kim, Byeong Hyo
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p. 366 - 367
(2007/10/03)
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- 3,5-DITERTIARYBUTYL-4-HYDROXYPHENYL, 1,3,4-THIADIAZOLES AND OXADIAZOLES LINKED BY CARBON, OXYGEN, AND SULFUR RESIDUES
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The novel 3,5-ditertiarybutyl-4-hydroxyphenylthio-1,3,4-thiadiazoles and oxadiazoles and 3,5-ditertiarybutyl-4-hydroxyphenylmethanone-l,3,4-thiadiazoles and oxadiazoles and related compounds of the present invention are antiinflammatory agents having activity as inhibitors of 5-lipoxygenase, cyclooxygenase or both
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- KINETICS OF THE REACTION OF 2,6-DI-t-BUTYLPHENOL WITH METHYL ACRYLATE IN THE PRESENCE OF POTASSIUM 2,6-DI-t-BUTYLPHENOLATE AND THE EFFECT OF PROTON-DONOR COMPONENTS ON THE MECHANISM OF THIS REACTION
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A kinetic scheme is proposed for the reaction of 2,6-di-t-butylphenol with methyl acrylate in the presence of potassium 2,6-di-t-butylphenolate.Rate constants have been calculated for the elementary stages which describe the mechanism of catalysis and the effect on the kinetic laws of the proton-donor components 2,6-di-t-butylphenol, water, and methanol.The kinetic scheme contains 30 components and includes 62 rate constants for the elementary stages, which were calculated by mathematical modeling of the kinetics of the process.The calculated results are compared with experimental data for the dependence of the rate of consumption of 2,6-di-t-butylphenol on the concentration of potassium 2,6-di-t-butylphenolate and on the concentrations of the proton-donor components.
- Volod'kin, A. A.
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p. 877 - 883
(2007/10/02)
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- REACTION OF 2,6-DI-TERT-BUTYLPHENOL WITH METHYL ACRYLATE IN THE PRESENCEOF BASES
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The alkylation of methyl 2-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate with methyl acrylate in the presence of lithium hydride at 160 deg C leads to derivatives of glutaric and trimethoxycarbonylhexanoic acids.The latter were detected in the products from the reaction of 2,6-di-tert-butylphenol with methyl acrylate or methyl β-methoxypropionate in the presence of bases.The composition of the reaction products was studied in relation to the nature of the solvent.
- Titova, T. F.,Krysin, A. P.,Bulgakov, V. A.,Mamatyuk, V. I.
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p. 1732 - 1737
(2007/10/02)
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