p-Xylene catalytic oxidation to terephthalic acid by ozone

Helin, Pan; Li, Shuting; Shu, Mingjie; Ye, Yuwei; Cui, Qiuhua; Zhao, Zhi‐Xiang

doi:10.2306/scienceasia1513-1874.2018.44.212

Cited by 18 publications

(2 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the same year, Pan et al [ 28 ] studied the catalytic oxidation of p- xylene to TPA by ozone in the presence of a cobalt catalyst. First, different salts of cobalt were tested under the following conditions: 110 °C, 0.10 mol of catalyst and 0.545 mmol of KBr per mol of p- xylene, 15 mg/L of ozone, a gas flow rate of 0.8 L/min, a duration of 6 h, and glacial acetic acid as a solvent.…”

Section: Catalytic Advancesmentioning

confidence: 99%

p-Xylene Oxidation to Terephthalic Acid: New Trends

Lapa

Martins

2023

Molecules

View full text Add to dashboard Cite

Large-scale terephthalic acid production from the oxidation of p-xylene is an especially important process in the polyester industry, as it is mainly used in polyethylene terephthalate (PET) manufacturing, a polymer that is widely used in fibers, films, and plastic products. This review presents and discusses catalytic advances and new trends in terephthalic acid production (since 2014), innovations in terephthalic acid purification processes, and simulations of reactors and reaction mechanisms.

show abstract

Section: Catalytic Advancesmentioning

confidence: 99%

p-Xylene Oxidation to Terephthalic Acid: New Trends

Lapa

Martins

2023

Molecules

View full text Add to dashboard Cite

show abstract

“…Позбутися цих проблем можна шляхом прямого окиснення відповідного 2-гідрокситолуолу озоном у рідкій фазі, оскільки вже відомі методи селективного озонування метилбензолів до відповідних оксигенпохідних [3][4][5][6]. Отже, актуальним є розроблення нового низько-температурного синтезу 2-гідроксибензилового спирту за допомогою озону.…”

Section: Ozonolytic Synthesis Of 2-hydroxybenzyl Alcohol For the Prod...unclassified

Ozonolytic synthesis of 2-hydroxybenzyl alcohol for the production of gastrodin

Halstian¹,

Hasanova²,

Tarasenko³

2023

АП

View full text Add to dashboard Cite

2-Hydroxybenzyl alcohol is an important active pharmaceutical ingredient for the production of many drugs, in particular gastrodin, which has a wide range of beneficial effects on epilepsy, Alzheimer’s disease, Parkinson’s disease, affective disorders, cerebral ischemia, cognitive disorders. It is known that 2- and 4-hydroxybenzyl alcohols and mixtures of both compounds are obtained by the interaction of phenol with formaldehyde in the presence of basic catalysts. Due to its high reactivity with formaldehyde, the isolation of pure compounds from the reaction mixtures obtained during the interaction of phenol with formaldehyde is a big problem. Isolation of 2-hydroxybenzyl alcohol in pure form from reaction mixtures is possible only using processes that cannot be carried out on an industrial scale and is accompanied by low yields of the target product. It is possible to get rid of these problems by means of the process of direct oxidation of the 2-hydroxytoluene with ozone in the liquid phase since methods of selective ozonation of methylbenzene to the oxygen derivatives are already known. Therefore, the development of a new low-temperature synthesis of 2-hydroxybenzyl alcohol using ozone is an urgent task. The aim of the work is to study the reaction of the oxidation of 2-hydroxytoluene by ozone in a solution of a stop reagent and catalytic impurities of compounds of transition metals and mineral acids for the development of a new method of synthesis of 2-hydroxybenzyl alcohol. Materials and methods. For the experiments, acetic anhydride of p. a. qualification was used; glacial acetic acid of puriss. qualification, which before use was purified by distillation under vacuum in the presence of potassium permanganate, 2-hydroxytoluene of puriss. Qualification, manganese (II) acetate of pur. Qualification, sulfuric and phosphoric acids of puriss. qualification. To determine the concentration of ozone in the gas phase, a spectrophotometric method was used, based on the measurement of the optical density of the gas flow in the UV region. For this purpose, a spectrophotometer SF-46 LOMO was used, in the measuring chamber of which a flow cuvette with quartz windows was installed. The material of the cuvette was Teflon. Continuous monitoring of the current concentration of ozone, with the recording of the analysis results in the form of a kinetic curve, was carried out when ozone-containing gas passed through the curette at a certain wavelength of a monochromatic light source. Results. The reaction of oxidation of 2-hydroxytoluene by ozone in a solution of the stop reagent – acetic anhydride was studied. It was shown that in the presence of sulfuric acid, it was possible to carry out direct ozonation of 2-hydroxytoluene to 2-hydroxybenzyl alcohol, which was formed in the kind of 2-acetoxybenzyl acetate with a yield of 13.0 %. The main products of the reaction under these conditions are aliphatic compounds, which are formed after the destruction of the aromatic ring. The selectivity of oxidation by alcohol was significantly increased when a catalyst – manganese (II) acetate – was added to the system. In its presence, a catalytic system As2O – H2SO4 – Mn(III) was created, which prevents ozonolysis and directed oxidation mainly to the methyl group of the substrate with the formation of 2-acetoxybenzyl acetate with a yield of 63.2 %. Conclusions. An environmentally friendly, low-temperature method for the synthesis of 2-hydroxybenzyl alcohol was developed by conducting the oxidation of 2-hydroxytoluene with ozone in a solution of the stop reagent – acetic anhydride in the presence of sulfuric acid and manganese (II) acetate.

show abstract

BP‐Amoco Mid‐Century Process for Terephthalic Acid Production (Case Study)

Gong¹

2023

Industrial Arene Chemistry

View full text Add to dashboard Cite

p-Xylene catalytic oxidation to terephthalic acid by ozone

Cited by 18 publications

References 9 publications

p-Xylene Oxidation to Terephthalic Acid: New Trends

p-Xylene Oxidation to Terephthalic Acid: New Trends

Ozonolytic synthesis of 2-hydroxybenzyl alcohol for the production of gastrodin

BP‐Amoco Mid‐Century Process for Terephthalic Acid Production (Case Study)

Contact Info

Product

Resources

About