Showing papers on "o-Cresol published in 2009"

Synthesis of carvacrol by Friedel–Crafts alkylation of o‐cresol with isopropanol using superacidic catalyst UDCaT‐5

Abstract: BACKGROUND: Alkylation of o-cresol with propylene or isopropyl alcohol (IPA) over solid acid catalysts results in the formation of carvacrol, which finds potential applications in the synthesis of fine chemicals, intermediates, specialty chemicals, flavours and fragrances. RESULTS: The present work covers evaluation of novel mesoporous superacidic catalysts namely UDCaT-4, UDCaT-5 and UDCaT-6 in the greener synthesis of carvacrol. The catalysts are modified versions of zirconia showing high catalytic activity, stability and reusability. The catalytic activity increases in the following order: UDCaT-5 > UDCaT-4 > UDCaT-6 > sulfated zirconia. The process was optimized and a mathematical model developed to describe the reaction pathway in liquid phase. Carvacrol could be efficiently obtained with a selectivity up to 82% at an isopropanol conversion of 98% after 2 h over UDCaT-5 at 180 °C. CONCLUSION: The reaction is free from any external mass transfer as well as intraparticle diffusion limitations and is intrinsically kinetically controlled. An overall second-order kinetic equation was used to fit the experimental data. The activation energy was found to be 19.2 kcal/mol. The reaction was carried out without any solvent in order to make the process cleaner and greener. Copyright © 2009 Society of Chemical Industry

Method for preparing o-cresol

Abstract: The invention discloses a method for preparing o-cresol, comprising the following steps: uniformly mixing phenol, 2, 6-dimethyl phenol and methanol with water by a mass ratio 34: (5-20): (33-46): (28-41), and then pumping the mixture into a reaction tube containing alkylate catalyst, introducing inert supporting gas to the reaction tube, and obtaining the o-cresol after condensating and recycling the reaction product The reaction conditions comprise normal atmosphere, reaction temperature of 280 to 450 DEG C, and the airspeed of incoming stock of 08-18h The method has advantages of simple technical process, high selectivity of o-cresol, relatively low selectivity of 2, 6-dimethyl phenol, no generation of by-products such as meta-cresol, p-cresol and anisole and long service life of the catalyst

Catalyst for alkylation of phenol and a method for producing o-cresol and 2,6-xylenol by using the catalyst

Abstract: A catalyst for alkylation of phenol and a method for producing o-cresol and 2,6-xylenol using the catalyst are provided to stably produce o-cresol and 2,6-xylenol to a high yield even without frequently performing a reactivating operation of the catalyst. A catalyst for alkylation of phenol is represented by the chemical formula 1, Fe1.0VaM1bM2cSidOx, where M1 denotes one or more components selected from the group consisting of cobalt(Co) and nickel(Ni), M2 denotes one or more components selected from the group consisting of manganese(Mn), molybdenum(Mo), zinc(Zn), and magnesium(Mg), catalyst components of Fe, V, M1, M2, and Si are present in the oxide state, a, b, c, and d denote mole ratios of the components V, M1, M2, and Si based on 1 mole of Fe, a ranges from 0.5 to 2, b rages from 0.01 to 0.5, c rages from 0 to 0.5, d rages from 0.01 to 1.0, and x is determined according to values of the a, b, c and d, and oxide states of the components Fe, V, M1 and M2 based on 1 mole of Fe.

Vapour Phase ortho-Selective Alkylation of Phenol with Methanol over Fe-Zr Oxide Catalysts

Abstract: Fe-Zr oxides with different Zr/Fe molar ratios were prepared by a co-precipitation method and used as catalysts for the vapor phase ortho-selective alkylation of phenol with methanol Results showed that the Fe-Zr oxide catalysts had relatively high activity and ortho-selectivity Among them, the sample with nZr/nFe=05/100 exhibited the highest activity (992% phenol conversion) with a selectivity of 226% to o-cresol and 770% to 2,6-xylenol An increase in reaction temperature could further improve selectivity for 2,6-xylenol The presence of relatively strong acid-base sites may be responsible for the high phenol conversion and the high 2,6-xylenol selectivity