4132-77-8Relevant academic research and scientific papers
Selective alkylation of xylenes by alcohols on zeolite catalysts
Isakov,Minachev,Kalinin,Isakova
, p. 2763 - 2768 (1996)
The peculiarities of catalytic performance of crystalline aluminosilicates of different types and compositions (X, Y including dealuminated Y′, mordenite, pentasil ZSM-5), as well as of amorphous aluminosilicate catalyst in conversion of xylene + alcohol mixtures were studied. New data were obtained for alkylation of o-xylene with tert-butyl alcohol, concerning controlling the selectivity and stability of the zeolite catalysts in reactions proceeding with the participation of water, including the water evolved during the reaction, in particular by controlling the acidic properties and hydrophobycity of the zeolites. A catalyst ensuring production of 1,2-dimethyl-4-tert-butylbenzene (DMTBB) with a 94% yield and selectivity of alcohol conversion to the target product of 94-97% was developed. The catalyst can be used as the basis for a high-performance and environmentally safe method for the synthesis of DMTBB. The catalysts developed can be also used for selective alkylation of o-xylene by C3-C5 alcohols and for alkylation of m-xylene by tert-butyl alcohol.
One-pot production of hydrocarbon oil from poly(3-hydroxybutyrate)
Kang, Shimin,Yu, Jian
, p. 14320 - 14327 (2014/04/17)
Poly(3-hydroxybutyrate) (PHB) is an energy storage material of many microbial species, and has been found to be an effective feedstock for production of renewable hydrocarbon oils. A high oil yield (up to 38.2 wt%) was obtained in a phosphoric acid (H3PO4) solution at mild temperatures (165-240 °C). PHB and crotonic acid (C4H 6O2), a dominant thermal degradation product of PHB, were deoxygenated mainly via decarboxylation, generating similar liquid and gaseous products. Carbon dioxide and propylene were the major products in gas phase with little CO formation. The hydrocarbon oil (C4-C16) is a mixture of alkanes, alkenes, benzenes and naphthalenes. Aromatics (C10-C15) were the major hydrocarbons in a 100 wt% H3PO4 solution, while alkenes and alkanes (C4-C9) were favored in diluted solutions (50 wt% to 85 wt% H 3PO4). The concentration of H3PO4 was a key factor that affected the oil composition and yield. A highly efficient decarboxylation of crotonic acid at 220 °C for 3 hours resulted in 70.8 wt% of oxygen being removed as CO2 and 57.0 wt% of carbon being recovered as hydrocarbon oil. The H3PO4 solution can be repeatedly used for high yield oil production. This work shows that a type of new biological feedstock can be used to produce renewable hydrocarbon oil in an efficient one-pot reaction. This journal is the Partner Organisations 2014.
Conversions of allyl ethers in a superbasic medium
Vyglazov,Chuiko,Izotova
, p. 933 - 939 (2007/10/03)
Conversions of alkyl allyl and terpenoid allyl ethers in a superbasic medium (dimethyl sulfoxide-potassium hydroxide) are studied. The ethers with an unbranched alkyl substituent isomerize into propenyl ethers, the ethers with a branched unsaturated substituent decompose to give a hydrocarbon, and diallyl ethers isomerize into allyl vinyl ethers whose Claisen rearrangement gives rise to aldehydes.
Isopropylation of xylenes catalyzed by ultrastable zeolite Y (USY) and some other solid acid catalysts
Patra, Chitta Ranjan,Kumar, Rajiv
, p. 216 - 224 (2007/10/03)
The isopropylation of all three xylene isomers was carried out over ultrastable zeolite Y (USY) catalyst to give corresponding dimethyl (1-methylethyl) benzenes, or in other words dimethyl cumenes (DMCs), using isopropanol as alkylating agent. The effect of reaction temperature, space velocity, substrate-to-alkylating-agent molar ratio, and time-on-stream on conversion of xylene isomers and selectivity to dimethyl cumene was studied. Isopropylation of xylenes over USY gives quite high (80 to 95%) DMC selectivity among the dimethyl cumenes, along with a 70-90% yield of DMCs in total products with respect to limiting reagents, i.e., isopropylating agents at relatively low reaction temperatures (423 ± 10 K) and at quite high xylene conversions (85-97% of theoretical maximum value). The solid acid catalysts zeolites H-Y, H-beta, H-mordenite, as well as silica-alumina and sulfated zirconia, were included for comparative studies in the isopropylation of m-xylene.
Thermal decomposition of 4-hydroxymethyl-2-carene esters
Chuiko,Vyglazov,Tychinskaya
, p. 1300 - 1304 (2007/10/03)
The kinetics of thermal decomposition of 2-caren-4-ylmethyl p-toluenesulfonate to 4-isopropenyl-1-methylbicyclo[4.1.0]hept-2-ene have been studied by 1H NMR spectroscopy. A mechanism is proposed, according to which the decomposition begins as a concerted process; the mechanism changes as p-toluenesulfonic acid accumulates in the mixture, and the process follows a ionic mechanism. Pyrolysis of esters formed by 4-hydroxymethyl-2-carene and boric acid is discussed in terms of the proposed mechanism.
Perfluorooctanesulfonic acid catalyzed Friedel-Crafts alkylation with alkyl halides
Fu,He,Lei,Luo
, p. 1273 - 1279 (2007/10/02)
A new procedure to prepare superacid perfluorooctanesulfonic acid (POSA) is reported. POSA catalyzed Friedel-Crafts alkylation of aromatic compounds with alkyl halides in liquid-phase reactions. Alkylation gave higher total yields than the corresponding reactions with Nafion-H, without the need of any complex decomposition or work-up. The reactions do not need to be carried out under absolutely anhydrous condition. The catalyst POSA can be easily separated from the reaction mixture and reused or recovered. The reactivity of the alkylation reagents and the mechanism of the reaction are discussed.
2-CARENE IN THE PRINS REACTION
Manukov, E. N.,Urbanovich, T. R.,Vyglazov, O. G.,Chuiko, V. A.,Skakovskii, E. D.
, p. 164 - 168 (2007/10/02)
The Prins reaction of 2-carene with formaldehyde has been studied.The main reaction product is 2-hydroxymethyl-3-carene.The dehydration of 2-hydroxymethyl-3-carene is accompanied by a skeletal rearrangement of the carane structure with the formation of products having a seven-membered ring.
Conversion of 1-Isopropylidene-4,4-dimethyl-2,5-cyclohexadiene to Its Crisscross Dimer
Nelsen, Stephen F.,Teasley, Mark F.
, p. 2667 - 2674 (2007/10/02)
The title compound, 1, gives only aromatization to 6 and polymerization upon treatment with acid in methylene chloride or when TFAA or TFA are added separately to the reaction mixture.When both TFAA and TFA are present at low temperatures, HBF4*Et2O cause
