1948-33-0Relevant articles and documents
Preparation and catalytic performance of perfluorosulfonic acid-functionalized carbon nanotubes
Zhang, Mengxiao,Li, Cuican,Hua, Weiming,Yue, Yinghong,Gao, Zi
, p. 1874 - 1882 (2014)
Perfluorosulfonic acid-functionalized carbon nanotubes were prepared by liquid deposition of the perfluorosulfonic acid-polytetrafluoroethylene copolymer and characterized by N2 adsorption, scanning electron microscopy, transmission electron mi
Sulfonic acid functionalized MCM-41 as solid acid catalyst for tert-butylation of hydroquinone enhanced by microwave heating
Ng, Eng-Poh,Mohd Subari, Siti Norbayu,Marie, Olivier,Mukti, Rino R.,Juan, Joon-Ching
, p. 34 - 41 (2013)
Covalently linked sulfonic acid (SO3H) modified MCM-41 mesoporous catalysts was prepared, characterized and its catalytic activity under microwave irradiation was evaluated. The NH2-MCM-41 was first prepared by anchoring (3-aminoprop
Candida antarctica lipase B-catalyzed regioselective deacylation of dihydroxybenzenes acylated at both phenolic hydroxy groups
Miyazawa, Toshifumi,Hamada, Manabu,Morimoto, Ryohei
, p. 44 - 49 (2015)
Candida antarctica lipase B proved to be highly active in the deacylation of substituted hydroquinones and resorcinols acylated at both phenolic hydroxy groups. The deacylation reactions were much faster than the corresponding direct acylations of these dihydroxybenzenes catalyzed by the same lipase. More importantly, they took place generally in a markedly regioselective manner: the acyloxy group remote from the substituent was preferentially cleaved. The main or exclusive products obtained were the regioisomers of those produced through the direct acylation of the dihydroxybenzenes. In the case of alkyl-substituted hydroquinone derivatives, the regioselectivity increased with an increase in the bulk of the substituent. In the case of 4-substituted diacylated resorcinols, the 3-O-monoacyl derivatives were obtained generally as the sole products. Quite interestingly, some secondary alcohols proved to act as better acyl acceptors than the corresponding primary alcohols in these enzymatic deacylations.
Method for synthesizing tert-butylhydroquinone
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Paragraph 0033-0035; 0042-0043, (2021/03/13)
The invention discloses a method for synthesizing tert-butylhydroquinone, and relates to tert-butylhydroquinone. The invention provides a synthesis method of tert-butylhydroquinone, and the method hasthe advantages of simple process and lower cost. The method comprises the following steps: 1) sequentially adding a catalyst sulfamic acid, a solvent toluene or xylene, tert-butyl alcohol, hydroquinone and 1, 4-dioxane into a heatable pressure-resistant reactor for reaction at 120-150 DEG C for 4-12 hours; 2) after the reaction is finished, adding ethanol, filtering to remove the catalyst sulfamic acid, and removing the solvent to obtain a crude product; 3) purifying the crude product obtained in the step 2) to obtain the product tert-butylhydroquinone. The defects that catalysts with high corrosivity are needed in the existing synthesis process, the process cost is high, the environmental pollution is serious, and the reaction selectivity is low are overcome.
Preparation method of high-purity 2-tert-butyl hydroquinone and purification method 2-tert-butyl hydroquinone
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Paragraph 0053-0174, (2020/03/25)
The preparation method 2 - of the high-purity,tert-butyl hydroquinone comprises the following steps: uniformly mixing, heating the hydroquinone, as a reaction solvent, heating temperature rise, to obtain,tert-butyl hydroquinone to obtain the high-purity,tert-butyl hydroquinone . The present invention further provides a preparation method of the high-purity tert-butyl hydroquinone and 2 - hours; of the hydrothermal filtration . The present invention further provides a method for purifying tert-butyl hydroquinone in,tert-butyl hydroquinone after the uniform mixing, of the reaction product 70 °C with water, to obtain the reaction crude product is obtained, 2 - by, heating and heating. the reaction 2 - medium 2 - to the reaction crude product by a heat-filtration temperature of more than two.
Tert-butylhydroquinone preparation method
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Paragraph 0025-0031, (2020/04/02)
The invention relates to the technical field of organic synthesis, and relates to a tert-butylhydroquinone preparation method, which comprises: 1) sequentially adding 2-tert-butylphenol, a transitionmetal copper (I) cooperation compound and a solvent to a high pressure reaction kettle, introducing oxygen to achieve a specified pressure, heating and stirring to a specified temperature, and carrying out a reaction for 0.5-3 h; 2) after the reaction is finished, evaporating out the solvent, washing the residual solid with a solvent, and carrying out steam stripping to obtain 2-tert-butyl p-benzoquinone; 3) sequentially adding the 2-tert-butyl p-benzoquinone obtained in the step 1), a catalyst and a solvent into a high-pressure reaction kettle, introducing hydrogen to a specified pressure after gas exchange is completed, heating and stirring to a specified temperature, and carrying out a reaction for 0.5-3 hours; and 4) after the reaction is finished, evaporating out the solvent, and rectifying to obtain the tert-butylhydroquinone product. According to the invention, the method has the advantages of high product yield, convenient operation, cheap raw materials, economy and reliability, and is suitable for large-scale production.
Can Donor Ligands Make Pd(OAc)2a Stronger Oxidant? Access to Elusive Palladium(II) Reduction Potentials and Effects of Ancillary Ligands via Palladium(II)/Hydroquinone Redox Equilibria
Bruns, David L.,Musaev, Djamaladdin G.,Stahl, Shannon S.
supporting information, p. 19678 - 19688 (2020/12/18)
Palladium(II)-catalyzed oxidation reactions represent an important class of methods for selective modification and functionalization of organic molecules. This field has benefitted greatly from the discovery of ancillary ligands that expand the scope, reactivity, and selectivity in these reactions; however, ancillary ligands also commonly poison these reactions. The different influences of ligands in these reactions remain poorly understood. For example, over the 60-year history of this field, the PdII/0 redox potentials for catalytically relevant Pd complexes have never been determined. Here, we report the unexpected discovery of (L)PdII(OAc)2-mediated oxidation of hydroquinones, the microscopic reverse of quinone-mediated oxidation of Pd0 commonly employed in PdII-catalyzed oxidation reactions. Analysis of redox equilibria arising from the reaction of (L)Pd(OAc)2 and hydroquinones (L = bathocuproine, 4,5-diazafluoren-9-one), generating reduced (L)Pd species and benzoquinones, provides the basis for determination of (L)PdII(OAc)2 reduction potentials. Experimental results are complemented by density functional theory calculations to show how a series of nitrogen-based ligands modulate the (L)PdII(OAc)2 reduction potential, thereby tuning the ability of PdII to serve as an effective oxidant of organic molecules in catalytic reactions.
A PROCESS FOR PREPARATION OF TERTIARY BUTYL HYDROQUINONE
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Page/Page column 9; 10; 11, (2020/07/15)
A PROCESS FOR PREPARATION OF TERTIARY BUTYL HYDROQUINONE The present invention relates to a process for preparation of tertiary butyl hydroquinone. More particularly, it relates to a process for preparation 5 of TBHQ by eradicating the consumption of hazardous solvents like toluene and eliminating hazardous impurities like hydroquinone, tertiary butyl‐p‐benzoquinone and also drastically reducing the presence of heavy metals like lead and arsenic. The present invention includes stages I‐IV in which TBHQ is more purified and precipitated with a high scale purity results. TBHQ has 10 application in food additives, animal feeds, as an antioxidant, emulsifier and in edible oils, effectively as antioxidant.
From simple phenols to potent chain-breaking antioxidants by transposition of benzo[1,4]oxathiines to benzo[b]thiophenes
Viglianisi, Caterina,Pietro, Leonardo Di,Meoni, Valentina,Amorati, Riccardo,Menichetti, Stefano
supporting information, p. 65 - 85 (2019/12/23)
Simple phenols, including food stock recycled derivatives, were used for the synthesis of 1,4-benzooxathiine intermediates, with limited or no antioxidant activity. Depending upon their substitution pattern, these compounds, through an acid promoted transposition, can be converted into o-hydroxydihydrobenzo[b]thiophenes or o-hydroxy-benzo[b]thiophenes as a new class of potent chain-breaking antioxidants, showing, in the reaction with alkyl peroxyl radicals, kinetic rate constants (kinh) comparable to that of α?tocopherol, the more potent natural lipophilic phenolic antioxidant.
1-Methyl-1,4-cyclohexadiene as a Traceless Reducing Agent for the Synthesis of Catechols and Hydroquinones
Baschieri, Andrea,Amorati, Riccardo,Valgimigli, Luca,Sambri, Letizia
, p. 13655 - 13664 (2019/10/28)
Pro-aromatic and volatile 1-methyl-1,4-cyclohexadiene (MeCHD) was used for the first time as a valid H-atom source in an innovative method to reduce ortho or para quinones to obtain the corresponding catechols and hydroquinones in good to excellent yields. Notably, the excess of MeCHD and the toluene formed as the oxidation product can be easily removed by evaporation. In some cases, trifluoroacetic acid as a catalyst was added to obtain the desired products. The reaction proceeds in air and under mild conditions, without metal catalysts and sulfur derivatives, resulting in an excellent and competitive method to reduce quinones. The mechanism is attributed to a radical reaction triggered by a hydrogen atom transfer from MeCHD to quinones, or, in the presence of trifluoroacetic acid, to a hydride transfer process.
