88-26-6Relevant academic research and scientific papers
Preparation method of antioxidant 330
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Paragraph 0027; 0029; 0031; 0033, (2021/01/29)
The invention relates to the technical field of chemical material processing, in particular to a synthetic method for preparing a hindered phenol antioxidant 330. The method comprises the following steps: reducing 3, 5-di-tert-butyl-4-hydroxybenzoic acid serving as an initial raw material into 3, 5-di-tert-butyl-4-hydroxybenzyl alcohol, and condensing the 3, 5-di-tert-butyl-4-hydroxybenzyl alcoholwith mesitylene under the action of an acid catalyst to generate the antioxidant 330. In the condensation reaction process, the phase transfer catalyst polyethylene glycol is utilized to improve thecatalytic effect of the concentrated sulfuric acid and reduce the consumption of the concentrated sulfuric acid, thereby having higher industrial value. The reaction yield is high, the optimal yield can reach 95%, the purity of the obtained reduction product is high, and in the industrial process, aftertreatment is simple. Therefore, the antioxidant 330 is synthesized by taking 3, 5-di-tert-butyl-4-hydroxybenzoic acid as an initial raw material and reducing 3, 5-di-tert-butyl-4-hydroxybenzoic acid into alcohol, and the method is a process route with relatively high industrial value.
Synthetic method of antioxidant
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Paragraph 0014; 0032; 0035; 0039; 0042; 0046; 0049; ..., (2021/06/23)
The invention discloses a synthesis method of an antioxidant, which comprises the following steps: reacting cyanuric chloride with an intermediate 8 and an intermediate 11 in sequence through temperature control to prepare an intermediate 12, hydrolyzing the intermediate 12, grafting a product on nano silicon dioxide to prepare the antioxidant; wherein the antioxidant is grafted with the nano silicon dioxide, so that the antioxidant can be fully dispersed when being mixed with a polymer, does not migrate along with the increase of service time, contains hindered phenol and phosphite structures, can provide hydrogen atoms to prevent the formation of chain free radicals, and reacts with the chain free radicals to achieve the purpose of inhibiting oxidation. Meanwhile, unstable hydrogen peroxide can be decomposed into stable compounds, so that formation of new free radicals is prevented, and the purpose of terminating a chain reaction is achieved.
Unusual transformation of 4-hydroxy/methoxybenzylic alcohols via C[sbnd]C ipso-substitution reaction using proton-exchanged montmorillonite as media
Chen, Dongyin,Chen, Xuan,Dong, Zezhong,Jiang, Nan,Li, Fei,Yun, Yangfang,Zhou, Yu
supporting information, (2020/11/12)
We present here proton-exchanged montmorillonite-mediated an unusual transformation of 4-hydroxy and 4-methoxybenzylic alcohols to form symmetrical benzylic ethers and diarylmethanes under mild conditions. Nuclear magnetic resonance spectroscopy and density functional theory calculations support a plausible mechanism, which includes a distinctive aromatic C[sbnd]C ipso-substitution reaction with a hydroxymethyl group as the C-based leaving group.
Comparative evaluation of the antioxidant activity of some ortho-substituted mono- and dialkylphenols with the para-positioned hydroxymethyl group
Buravlev, E. V.,Fedorova, I. V.,Kutchin, A. V.,Shevchenko, O. G.
, p. 1573 - 1578 (2020/09/21)
The para-hydroxymethyl derivatives of 2,6-di-tert-butylphenol, 2,6-diisobornylphenol, 2-isobornyl-6-tert-butylphenol, 2-isobornyl-6-methylphenol, and 2-isobornylphenol were synthesized. A comparative evaluation of the antioxidant properties of the synthesized compounds was carried out in in vitro models. The activity of derivatives is predetermined by the number and bulkiness of the substituents at the ortho positions relative to the phenolic OH group and is consistent with the relationships previously identified by us for other phenolic antioxidants.
Synthetic method of 4-hydroxymethyl-2, 6-di-tert-butylphenol
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Paragraph 0007; 0008; 0009, (2018/10/26)
The invention provides a synthetic method of 4-hydroxymethyl-2, 6-di-tert-butylphenol. The synthetic method includes the steps of adopting the 2, 6-di-tert-butylphenol and paraformaldehyde or formaldehyde aqueous solution as starting material, adding solvent and catalysts, performing one-step reaction in a hydrothermal synthesis reactor and under a certain reaction temperature for a certain reaction time and then generating a target product. The synthetic method of 4-hydroxymethyl-2, 6-di-tert-butylphenol has the advantages of simple steps, convenient operation, green reaction process, and higher synthesis efficiency than an existing synthesis method.
Preparation method of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol
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Paragraph 0015, (2017/08/30)
The invention discloses a preparation method of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and belongs to the technical field of organic synthesis. In the technical scheme, a reaction is carried out to 2,6-di-tert-butyl-phenol and a Vilsmeier reagent in a non-protonic solvent at 60-80 DEG C to generate 3,5-di-tert-butyl-4-hydroxybenzaldehyde; and then the 3,5-di-tert-butyl-4-hydroxybenzaldehyde is reacted with a strong-protonic reducing agent to generate the target product, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol. The method is free of special catalyst and is free of gas in the reactions, is high in reaction yield, and is free of complex product post-treatment step, so that the method has wide application prospect.
Structure, thermal stability, antioxidant activity and DFT studies of trisphenols and related phenols
Yu, Shasha,Wang, Yishan,Ma, Yujie,Wang, Limin,Zhu, Jia,Liu, Shenggao
, p. 159 - 170 (2017/10/05)
Two kinds of trisphenols have been successfully synthesized and their structures were confirmed by IR spectra, 1HNMR, 13CNMR, mass spectra and X-ray diffraction. They exhibited better thermal stability than both monophenol and bisphenols due to their higher molecular weight. Moreover, their antioxidant activities have been investigated in lubricant oil using PDSC and RBOT. The results showed that the o-trisphenol 3b exhibited the best antioxidant activity while the p-trisphenol 3a was the worst. In addition, their relationship between structures and properties has been further explored by a series of DFT calculations including the BDE values, the IP values and the Gibbs free energy barriers for the reaction between phenols and methylperoxyl radicals.
Hydrogenation of aldehydes and ketones to corresponding alcohols with methylamine borane in neat water
Duan, Yifan,Bai, Ruijiao,Tian, Jun,Chen, Ligong,Yan, Xilong
, p. 2555 - 2564 (2014/08/05)
GRAPHICAL ABSTRACT Chemoselective hydrogenation of various aldehydes and ketones with methylamine borane (MeAB) in neat water was investigated. MeAB is suitable for green organic reactions, for MeAB is a nontoxic, environmentally benign, and easily handled reagent. Aldehydes were selectively and rapidly hydrogenated in excellent yields (86-97%) for 30 min, but hydrogenation of aromatic ketones needed over 20 h at room temperature because of their poor water solubility and steric hindrance. Thus we investigated polyethylene glycol (PEG400) and acidic cation-exchange D072 resin as catalysts to accelerate the hydrogenation reaction of aromatic ketones and achieved excellent yields within several hours. PEG 400 and D072 resin are both suitable for green organic reactions. The D072 resin was reused up to four times without any significance loss in activity.
Hydrolysis of the quinone methide of butylated hydroxytoluene in aqueous solutions
Willcockson, Maren Gulsrud,Toteva, Maria M.,Stella, Valentino J.
, p. 3579 - 3585 (2013/09/24)
Butylated hydroxytoluene or BHT is an antioxidant commonly used in pharmaceutical formulations. BHT upon oxidation forms a quinone methide (QM). QM is a highly reactive electrophilic species that can undergo nucleophilic addition. Here, the kinetic reactivity of QM with water at various apparent pH values in a 50% (v/v) water-acetonitrile solution at constant ionic strength of I =?0.5 (NaCl)4, was studied. The hydrolysis of QM in the presence of added acid, base, sodium chloride, and phosphate buffer resulted in the formation of only one product--the corresponding 3,5-di-tert-butyl-4-hydroxybenzyl alcohol (BA). The rate of BA formation was catalyzed by the addition of acid and base, but not chloride and phosphate species. Nucleophilic excipients, used in the pharmaceutical formulation, or nucleophilic groups on active pharmaceutical ingredient molecule may form adducts with QM, the immediate oxidative product of BHT degradation, thus having implications for drug product impurity profiles. Because of these considerations, BHT should be used with caution in formulations containing drugs or excipients capable of acting as nucleophiles.
