Synthesis of 2,6-Xylenol by Alkylation of Phenol with Methanol

doi:10.1016/S0166-9834(00)83240-6

Applied Catalysis

Volume 47, Issue 2, 15 February 1989, Pages 351-355

https://doi.org/10.1016/S0166-9834(00)83240-6 Get rights and content

Abstract

Iron catalysts modified with chromium, silicon, potassium or caesium ions were investigated in the synthesis of 2,6-xylenol by alkylation of phenol wit

Reference (12)

InoueM. et al.
Chem. Pharm. Bull.
(1976)
B.E. Leach, U.S. Pat, 4 227 024,...
IpatieffV.N. et al.
Bull. Soc. Chim. Fr.
(1925)
M. Froitzhein, K.F. Lang, L. Rappen and J. Turowski, Ger. Offen., 1 248 666,...
J.E. Dabrowski, Ger. Offen, 2 704 440,...
W.E. Smith, Ger. Offen, 2 716 035,...

There are more references available in the full text version of this article.

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Our study not only paves the way for industrial production of HFE-356mmz, but also expands the application of metal fluorides. Metal fluorides (AlF3, MgF2, CaF2, SrF2, and BaF2) were prepared by fluorination of the corresponding metal oxides (Al2O3, MgO, CaO, SrO, and BaO) [21,22], in which MgO and Al2O3 were obtained by a precipitation method. The typical process for synthesizing MgF2 was as follows: Mg(NO3)2 (148 g, 1.0 mol) was dissolved in distilled water (400 ml) and stirred for 1 h, then ammonium hydroxide (5 %) was slowly added to the solution at room temperature until pH = 8.5 was reached.
1,1,1,3,3,3-Hexafluoroisopropylmethyl ether (HFE-356mmz) is an important substitute for chlorofluorocarbons and hydrochlorofluorocarbons due to its zero ozone depletion potential and low global warming potential. However, mass production of HFE-356mmz remains a long-standing challenge. Herein, we applied metal fluorides as catalysts in the methylation of 1,1,1,3,3,3-hexafluoroisopropanol to produce HFE-356mmz for the first time.
The catalyst not only improves the synthetic efficiency, but also makes the reaction solvent-free.
The pollution-free, recyclable, and continuous synthetic process enables industrial production of HFE-356mmz. To optimize the synthetic efficiency, a series of metal fluorides (AlF₃, MgF₂, CaF₂, SrF₂, and BaF₂) was used, among which MgF₂ exhibited the highest activity. Through careful examination of each metal fluoride, it was found that the activity of the catalyst was determined by co-operative action of the surface acid–base properties and the total amount of surface acid sites. Based on these results, a rational mechanism for the vapor-phase methylation was proposed.
The constructing of Si-Fe-Sn co-solution surface of composite iron oxide catalyst via vapor methanol pretreatment and application in gaseous phenolic alkylation
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Many processes adopt hematite materials as the main phase of their catalysts, such as water-gas shifting (WGS) [12], methanol decomposition [14–16], and phenols alkylation [17–28]. For the gaseous phenolic alkylation, H. Grabowska et al. [21] used Cr, Si, and K as additives to modify the iron oxide catalysts, and finally developed a Fe-Si-Cr-K catalyst with excellent activity (93.8% of yield) for the synthesis of 2,6-dimethylphenol by alkylation of phenol with methanol. These catalysts were also successfully applied to the gaseous alkylation of naphthols with C1-C3 alcohol and exhibited excellent activity with an ortho-alkylation selectivity of more than 98% [19].
Iron oxide catalysts which were used in gaseous 2,5-dimethylphenol (2,5-DMP) alkylation with methanol was modified by Sn, Si and K to produce 2,3,6-trimethylphenol (2,3,6-TMP). Characterized by FE-SEM, ICP-OES, XRD, Raman, in-situ FT-IR, N₂-adsorption/desorption, XPS, FE-TEM and NH₃-TPD. The primary surface segregated SnO₂ nanocrystals and the amorphous Si-containing coordination structures which were formed on non-activated catalyst limited the growth of hematite grains; catalysts activation triggered by vapor methanol successfully formed a surface Si-Fe-Sn ternary co-solution structure through lattice oxygen consumption and migration, which passivated the uniformity of grains and blocked the direct contact between them; K was used to weaken the acidity of undesirable strong acid sites. The main product was proved to be 2,3,6-TMP by ¹H NMR, which is a synthetic intermediate of vitamin E with high value. The best 2,5-DMP conversion and 2,3,6-TMP selectivity can reach 99.25% and 100% under the condition of 370 °C and 1.5 h⁻¹ LHSV, respectively. Compared with traditional iron oxide catalysts, the undesirable sintering has been reduced by 23.2% and 2,3,6-TMP productivity is 1.5 times that of the reference data because of this structure. This work provides a good reference for the improvement of other iron-based materials used in complex reductive atmosphere.
Effect of calcination temperature on the structure and hydroxylation activity of Ni <inf>0.5</inf> Cu <inf>0.5</inf> Fe <inf>2</inf> O <inf>4</inf> nanoparticles
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It indicated that the hydroxylation activity of spinels depends on the distribution of cations among the octahedral and tetrahedral sites. On the other hand, the octahedral sites are exclusively exposed at the surface of the spinel crystallites and thus the catalytic activity is mainly related to the octahedral cations [47,48]. It has been reported that the octahedral ions presented in the spinel crystal lattice were responsible for the activity towards oxidation reactions [43,49].
Nanocrystalline Ni_0.5Cu_0.5Fe₂O₄ was synthesized by sol–gel method with varying calcination temperature over the range of 500–1000. The powders obtained were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). In addition, thermal analysis (TG–DTG–DTA) of the precursor was carried out. The study reveals the simultaneous decomposition and ferritization process at rather low temperature (280–350). For the crystalline structure investigated, single cubic spinel is gained when the precursor was decomposed at 800–1000, whereas separated crystal CuO formed when calcination temperature is below 800. The increase of calcination temperature favors the appearance of Fe_B³⁺, Cu_A²⁺ and O on the spinel surface. The hydroxylation activity is relative to the amount of Cu_B²⁺ species on the spinel surface. The lattice oxygen species on the spinel surface are favorable for the deep oxidation of phenol.
Effect of synthesis method of LSCF perovskite on its catalytic properties for phenol methylation
2010, Solid State Ionics
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The synthesis of phenol methyl derivatives has been the subject of numerous investigations. A wide spectrum of catalysts for the gas phase phenol methylation have been reported in the literature, including single metal oxides [16–20], mixed metal oxides [21–24], especially these ones containing iron oxide [25,26], zeolites [27–29], spinels, ferrites and others [30–34]. Previous studies on alkylation of phenol by methanol showed the role of acid–base properties of catalyst on its activity and selectivity towards desirable reaction products [35,36].
Mixed oxides with perovskite-like structure and the same formal composition La_0.6Sr_0.4Co_0.2Fe_0.8O₃ (LSCF) were prepared by combustion synthesis and by reactive grinding method. Properties of these materials were compared with properties of a commercially available LSCF mixed oxide. The samples were characterized using XRD, ICP, XPS, TEM, SEM, TPR-H₂, specific surface area (SSA) and acid–base measurements. It was found that although studied materials exhibit similar physicochemical properties they show different catalytic behaviour for phenol alkylation with methanol. Such behaviour can be attributed to differences in surface structure caused by different synthesis route. The main reaction product, i.e. ortho-cresol, was obtained with selectivity higher than 90% (in the whole studied temperature range) at conversion level up to 41% on the material prepared by reactive grinding.
Effect of preparation method on the surface properties and activity of Ni<inf>0.7</inf>Cu<inf>0.3</inf>Fe<inf>2</inf>O<inf>4</inf> nanoparticles
2010, Journal of Alloys and Compounds
Ni_0.7Cu_0.3Fe₂O₄ nanoparticles were synthesized via sol–gel combustion technique, co-precipitation method and solid state milling method. Simultaneous thermogravimetric and differential thermal analysis (TG–DTA) was carried out to monitor the decomposition process of the precursors. The samples were characterized by Fourier transform infrared (FT-IR), inductively coupled plasma spectroscopy (ICPS), X-ray diffraction (XRD), BET surface area measurement, scanning electron microscopy (SEM), transmission electron microscopy (TEM), temperature programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS). TG–DTA traces of the precursors show that the crystallization temperature for spinel formation by sol–gel combustion technique is lower than those by co-precipitation method and solid state milling method. XRD analysis reveals that the powders obtained are single phase with cubic spinel structure. Mutual promotion of reduction performance between CuO and NiFe₂O₄ is observed from TPR patterns. The experimental study indicates that the copper in the octahedral sites plays a crucial role in the direct oxidation of benzene with hydrogen peroxide as oxidant to phenol.
Catalytic methylation of phenol on MgO - Surface chemistry and mechanism
2010, Journal of Catalysis
Reactions of phenol and methanol catalyzed by MgO have been explored by kinetic measurements and in situ IR spectroscopy combined with computational studies of sorbed molecules. On MgO, methanol partly transforms to formaldehyde above 250 °C. Adsorbed phenol forms phenolate species, and the energetically preferred mode of adsorption leads to an almost orthogonal orientation of the aromatic ring with respect to the catalyst surface. All molecules involved adsorb preferably at the corner sites of MgO (three-co-ordinated Mg atoms). The main reaction products are anisole and o-cresol, the latter dominating above 300 °C. At very low conversions, salicylic aldehyde is observed as primary reaction product, being rapidly transformed to o-cresol. It is only observed during the initial accumulation of adsorbed species on the catalyst surface, but not under steady-state conditions on a fully covered catalyst surface. Therefore, o-cresol formation starts with the reaction between phenol and formaldehyde to salicylic alcohol, which in turn is rapidly transformed to salicylic aldehyde and subsequently to o-cresol. Salicylic aldehyde may also form via the bimolecular disproportionation of salicylic alcohol to o-cresol and aldehyde. The parallel reaction to o-cresol, not involving the formation of salicylic aldehyde as intermediate, proceeds via the reduction of salicylic alcohol to o-cresol by formaldehyde. The identified mechanism may open new synthetic approaches for the production of functionalized phenol derivatives and, even more importantly, for the defunctionalization of substituted phenols potentially available at large scale from deconstructed lignin.

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Synthesis of 2,6-Xylenol by Alkylation of Phenol with Methanol

Abstract

Chem. Pharm. Bull.

Bull. Soc. Chim. Fr.