Alkylation of p-cresol with tert-butanol catalyzed by heteropoly acid supported on zirconia catalyst

Devassy, Biju M.; Shanbhag, Ganapati V.; Lefèbvre, Frédéric; Halligudi, S.B.

doi:10.1016/j.molcata.2003.09.015

Cited by 62 publications

(38 citation statements)

References 15 publications

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“…The another reason is due to lower deactivation caused in supercritical CO 2 compared to conventional organic solvents [3]. The yield of 2,6-DTBPC (53%) observed for HPW(30)/MCM-41 was the highest yield ever observed in literature: the maximum yield of DTBC was 20% in the vapor phase reaction [14]. The t-butylation of p-cresol over relatively weaker HSiW the support for highly dispersed HPW, and provides the reaction circumstances for the formation of bulky 2,6-DTBPC by the cooperation of strong acid.…”

Section: Resultsmentioning

confidence: 99%

“…Alkylation of p-cresol with t-butanol produces industrially important organic intermediates, such as 2-t-butyl-4-methylphenol (2-TBPC) and 2,6-di-tbutyl-4-methylphenol (2,6-DTBPC), which are widely used in antioxidants and polymerization inhibitors and in the manufacture of phenol resins [7]. Recently, many workers have been attention to the liquid phase or vapor phase t-butylation of phenols over solid acid catalysts, such as zeolites [9][10][11], clays [12], metal oxides [13], and mesoporous materials [14][15][16][17][18][19][20] including their modified catalysts; however, there have been a few to succeed in the di-t-butylation of phenols. We have considered one of the reasons is the deactivation of acidic sites by coke formation.…”

Section: Introductionmentioning

confidence: 99%

“…Tungstophosphoric acid (HPW) modified mesoporous zirconia and cobalt aluminophosphate were used for catalysts in the synthesis of t-butyl cresols in liquid or vapor phase [13,14]. However, they mainly discussed on the selective synthesis of mono butyl cresols.…”

Section: Introductionmentioning

confidence: 99%

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The Di-t-butylation of p-cresol with t-butanol in Supercritical CO2 over Tungstophosphoric Acid Supported on Ordered Mesoporous Silica

2006

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Tungstophosphoric acid (HPW) supported on MCM-41 was an excellent catalyst for the t-butylation of p-cresol to 2,6-di-tbutyl-4-methylphenol (2,6-DTBPC) in supercritical CO 2 ; however, zeolites, H-Y and H-Beta, only gave 2-t-butyl-4-methylphenol (2-TBPC) because of their limitation in pore size. The yield of 2,6-DTBPC was maximized at 110°C, and further increase in temperature rather decreased the yield. The yield of 2,6-DTBPC was maximized at 10-11 MPa CO 2 pressure, and further increase of the pressure decreased in the conversion of phenol and the yield of 2,4-DTBC. The thermogravimetric analysis of used catalysts showed that the coke-formation was minimized in supercritical CO 2 compared to the other reaction media such as in liquid phase and in N 2 atmosphere.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The Di-t-butylation of p-cresol with t-butanol in Supercritical CO2 over Tungstophosphoric Acid Supported on Ordered Mesoporous Silica

2006

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“…But the catalyst deactivated due to the leaching of active sites [ 32 ]. For tert -butylation of p -cresol with tert -butanol, 15 % PTA/ZrO 2 (calcined at 750 °C) was also studied under continuous down-fl ow conditions [ 33 ]. The catalyst gave good p -cresol conversion (~60 %) and high selectivity (~90 %) for TBC.…”

Section: Veratrole Acylation With Benzoic Anhydridementioning

confidence: 99%

Supported Heteropoly Acids and Multicomponent Polyoxometalates as Eco-Friendly Solid Catalysts for Bulk and Fine Chemicals Synthesis

Shanbhag

Bordoloi

Sahoo

et al. 2013

Environmentally Benign Catalysts

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Supported heteropoly acids are an important class of eco-friendly solid catalysts which offer strong acidity or redox properties. Part 1 of this chapter gives the detailed description of Keggin heteropoly acids such as silicotungstic acid (STA) and phosphotungstic acid (PTA) supported on zirconia as thermally stable, reusable solid catalysts which can be used for variety of organic transformations such as alkylation, acylation, and allylation. The catalysts are characterized by various techniques such as X-ray diffraction, N 2 sorption measurements, DTG-DTA, UV-Vis spectroscopy, FTIR pyridine adsorption, NH 3 -TPD, FT-Raman, and 31 P MAS NMR. These supported HPA catalysts found to be highly active and selective with a long catalytic

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“…The traditional catalysts include sulfate, phosphate [5,6], cation exchange resin [7], SO 4 2-/ZrO 2 supported on HMS [8] and heteropolyacid supported on ZrO 2 [9]. However these catalysts more or less have the shortcomings of large dosage, strong corrosion, complex post-treatment technology, environmental pollution, deep colored products and poor reproducibility.…”

Section: Choice and Preparation Of The Catalystmentioning

confidence: 99%

Synthesis of Liquid Antioxidant DTBNP Catalyzed by Composite Super Acid~!2009-08-11~!2009-10-27~!2009-12-31~!

Yu¹,

Li²

2010

TOCATJ

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2,6-Di-tert-butyl-4-nonylphenol(DTBNP) was synthesized from 4-n-nonyl phenol and isobutylene, etc. using self-made composite super acid as catalyst. The appropriate technology conditions are as follows: reaction temperature is 60-80 , reaction time is 4h, n 4-n-nonyl phenol : n Isobutylene = 1: 2 and the amount of catalysts is 0.019% of the quantity of 4-n-nonyl phenol reactant, the yield can reach to 98%.Keywords: Liquid antioxidant DTBNP, 4-n-nonyl phenol, isobutylene, composite super acid, catalyst.2, 6-Di-tert-butyl-4-nonylphenol (DTBNP) is a new kind of liquid hindered phenolic antioxidants. It does not have the defects shared by the traditional solid antioxidants (BHT and T501) such as low dispersibility in protective solute, yellowing and decoloring, and short time of antioxidation [1,2], because DTBNP has a higher molecular weight than the traditional phenolic antioxidants. It has low volatility and could keep liquid state at room temperature. Therefore much attention has been focused on the research of liquid hindered phenolic antioxidants [3,4].In this research, 4-n-nonyl phenol, isobutylene and selfmade composite super acid was used to catalyze the alkylation reaction in order to synthesize DTBNP. As a parent substance of liquid hindered phenolic antioxidants, DTBNP combined with other functional additives can be made into various liquid anti-oxidizers.

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Alkylation of p-cresol with tert-butanol catalyzed by heteropoly acid supported on zirconia catalyst

Cited by 62 publications

References 15 publications

The Di-t-butylation of p-cresol with t-butanol in Supercritical CO2 over Tungstophosphoric Acid Supported on Ordered Mesoporous Silica

The Di-t-butylation of p-cresol with t-butanol in Supercritical CO2 over Tungstophosphoric Acid Supported on Ordered Mesoporous Silica

Supported Heteropoly Acids and Multicomponent Polyoxometalates as Eco-Friendly Solid Catalysts for Bulk and Fine Chemicals Synthesis

Synthesis of Liquid Antioxidant DTBNP Catalyzed by Composite Super Acid~!2009-08-11~!2009-10-27~!2009-12-31~!

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