- Heteropoly Acids Supported on Acidic Ion-exchange Resin as Highly Active Solid-acid Catalysts
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Heteropoly acids supported on a macroreticular acidic ion-exchange resin shows much higher activity than those supported on activated carbon for the synthesis of methyl t-butyl ether and the esterification of acetic acid with 1-pentanol.This high activity can plausibly be attributed to the interaction of heteropoly anions with substrates which are protonated by the protons of the acidic resin.
- Baba, Toshihide,Ono, Yoshio,Ishimoto, Tadao,Moritaka, Shun-ichi,Tanooka, Seiichi
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- Activity of Polymeric and Zeolite-Containing Catalysts in Production of Methyl tert-Butyl Ether
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The effect of structural and acid characteristics of catalysts of various nature (sulfonic cation exchangers of the KU-23 type and high-silica zeolite of the ZSM-5 type) on their activity and selectivity in production of methyl tert-butyl ether from isobutylene and methanol was studied.
- Koval',Bazhina,Safronova,Perevezentsev,Kosukhin,Erofeev,Ryabov
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- High-pressure heat-flow calorimeter. Determination of the enthalpy of reaction for the synthesis of methyl t-butyl ether from methanol and 2-methylpropene
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A high-pressure heat-flow calorimeter suitable for measuring enthalpies of reaction and heat capacities is described.With the calorimeter, thermodynamic properties can be studied from 290 to 600 K and from 0.1 to 10 MPa.The reaction enthalpy for the synthesis of methyl t-butyl ether from methanol and 2-methylpropene using an acidic ion-exchange-resin catalyst was measured at 319 K and 1.6 MPa.The molar reaction enthalpy is given by ΔrHm(319 K, 1.6 MPa) = -(39.8 +/- 0.4)kJ.mol-1.The corresponding standard molar enthalpy of formation of methyl t-butyl ether is ΔfHm0(l, 298.15 K) = -315.4 kJ.mol-1.
- Arntz, H.,Gottlieb, K.
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- Gas phase synthesis of MTBE on triflic-acid-modified zeolites
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The gas phase synthesis of MTBE (methyl tert-butyl ether) was studied using three series of triflic acid (TFA)-modifled zeolites, the parent materials being HY, H-mordenite, and HZSM-5. Impregnation with TFA was found to enhance MTBE synthesis activity only for the large-pore zeolite Y and only up to a certain extent of modification. A high level of TFA modification caused a reduction in activity, apparently due to blockage of the active sites by TEA molecules and extra-lattice Al formed during the modification process. The mechanism of activity enhancement by TEA modification appears to be related to the formation of extra-lattice Al rather than the direct presence of TFA.
- Nikolopoulos,Kogelbauer,Goodwin Jr.,Marcelin
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- Gas phase synthesis of MTBE from methanol and isobutene over dealuminated zeolites
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Gas phase synthesis of MTBE from methanol and isobutene has been investigated over different zeolites. It is shown that bulk Si/Al ratio has a marked influence on the formation of MTBE. H-beta zeolite was found to be as active as acid Amberlyst-15 (reference catalyst), and noticeably superior to non- and dealuminated forms of H-Y, H-ZSM-5, zeolite omega, and H-mordenites. Screening test results obtained over other catalysts (SAPOs and pillared clays) are briefly commented. The contribution of the external surface of the zeolites to the reaction is discussed. In the case of H-Y zeolites, it is shown that extraframework Al species (27Al NMR signal at 30 ppm) have a detrimental effect on the reaction.
- Collignon,Mariani,Moreno,Remy,Poncelet
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- On Anchimerically Assisted Homolysis via Sulphide Functions
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In contrast to O-O fission, anchimeric assistance from sulphide functions in the rate of unimolecular fission of the N-O bond is only marked for heterolysis reactions; analogous homolyses are very much less accelerated, although bridged radical intermediates are involved.
- Lawson, Alexander J.
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- Determination of adsorption and kinetic parameters for methyl tert-butyl ether synthesis from tert-butyl alcohol and methanol
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Synthesis of MTBE by direct reaction between methanol and tert-butyl alcohol (TBA) on acid ion-exchange resin, Amberlyst 15, packed in a reactor was studied at 318-328 K and at different flow rates. A mathematical model based on a quasi-homogeneous kinetics was developed, assuming the reaction in the polymer phase to be homogeneous. H2O traveled more slowly than MTBE. The reaction rate increased with increasing reaction temperature, and the conversion of the limiting reactant, TBA, was favored at high temperatures and at low flow rates of TBA. The adsorption constant of H2O was almost 10 times greater than that of MTBE and as a result, the desired product MTBE always elutes faster than H2O. The effects of temperature on forward reaction constant, and reaction equilibrium constant were also explored. The activation energy for the reaction was 130.1 kJ/mole. The fitted parameters obtained for enthalpy and entropy of adsorption from Arrhenius plots were consistent with thermodynamics when the standard states were changed to liquid at 1 mole to pure gas at 1 atm. The accuracy of the proposed mathematical model was further verified when it was observed that the model could predict experimental results at different feed concentrations and flow rates quite well.
- Ray,Ziyang,Hidajat
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- Kinetics of liquid phase synthesis of methyl tert-butyl ether from tert-butyl alcohol and methanol catalyzed by ion exchange resin
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Synthesis of methyl tert-butyl ether (abbreviated as MTBE) from methanol (MeOH) and tert-butyl alcohol (TBA) in the liquid phase was studied by using Amberlyst 15 in the H+ form as an acid catalyst. Experiments were carried out in a stirred batch reactor at different temperatures (313, 318, and 323 K) under atmospheric pressure. It was found that catalyst sizes and rotation speeds had no significant effects on reaction rates. Mechanism studies showed that three reactions took place simultaneously. It was also found that dehydration of TBA could not be neglected. The experimental concentration profiles with time could be simulated well by simple kinetics. Finally, rate constants could be expressed by Arrhenius equations.
- Matouq,Goto
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- Strong influence of the polyanion structure on the secondary structure of solid heteropolyacids and their catalytic activity; methyl tert-butyl ether synthesis in the pseudo-liquid phase of heteropolyacids
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It has been shown that the high catalytic activity of a Dawson-type heteropolyacid for gas-phase methyl tert-butyl ether synthesis at low temperatures is attributable to its amorphous secondary structure, which brings about a flexible pseudo-liquid phase and facilitates rapid absorption and desorption of molecules.
- Shikata, Sawami,Misono, Makoto
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- Catalysis in a porous molecular capsule: Activation by regulated access to sixty metal centers spanning a truncated icosahedron
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The 30 cationic {MoV2O4(acetate)} + units linking 12 negatively charged pentagonal "ligands," {(MoVI)MoVI5O21(H 2O)6}6- of the porous metal-oxide capsule, [{MoVI6O21(H2O)6} 12{MoV2O4(acetate)} 30]42- provide active sites for catalytic transformations of organic "guests". This is demonstrated using a well-behaved model reaction, the fully reversible cleavage and formation of methyl tert-butyl ether (MTBE) under mild conditions in water. Five independent lines of evidence demonstrate that reactions of the MTBE guests occur in the ca. 6 × 10 3 A3 interior of the spherical capsule. The Mo atoms of the {MoV2O4(acetate)}+ linkers - spanning an ca. 3-nm truncated icosahedron - are sterically accessible to substrate, and controlled removal of their internally bound acetate ligands generates catalytically active {MoV2O4(H 2O)2}2+ units with labile water ligands, and Lewis- and Bronsted-acid properties. The activity of these units is demonstrating by kinetic data that reveal a first-order dependence of MTBE cleavage rates on the number of acetate-free {MoV2O 4(H2O)2}2+ linkers. DFT calculations point to a pathway involving both Mo(V) centers, and the intermediacy of isobutene in both forward and reverse reactions. A plausible catalytic cycle - satisfying microscopic reversibility - is supported by activation parameters for MTBE cleavage, deuterium and oxygen-18 labeling studies, and by reactions of deliberately added isobutene and of a water-soluble isobutene analog. More generally, pore-restricted encapsulation, ligand-regulated access to multiple structurally integral metal-centers, and options for modifying the microenvironment within this new type of nanoreactor, suggest numerous additional transformations of organic substrates by this and related molybdenum-oxide based capsules.
- Kopilevich, Sivil,Gil, Adria,Garcia-Rates, Miquel,Bonet-Avalos, Josep,Bo, Carles,Mueller, Achim,Weinstock, Ira A.
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- Coadsorption of methanol and isobutene on HY zeolite
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In order to develop a better understanding of methyl tert-butyl ether (MTBE) synthesis on zeolites, the coadsorption of methanol and isobutene on HY zeolite was investigated using IR spectroscopy. Initial adsorption of isobutene alone at 35°C led to rapid oligomerization yielding strongly bound oligomers. The subsequent coadsorption of methanol did not induce any changes in the zeolite-adsorbate complexes. TPD following the coadsorption showed that the Bronsted acid sites could be restored by temperature treatment above approximately 300°C. When methanol was adsorbed first and isobutene was subsequently coadsorbed, MTBE was formed even at 35°C on the catalyst surface. MTBE desorbed easily at a temperature of 70°C, restoring a major fraction of the Brosted acid sites. Methanol was concluded to decrease the probability of oligomerization by effectively competing for the acid sites.
- Kogelbauer,Goodwin,Lercher
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- Liquid phase synthesis of MTBE from methanol and isobutene over acid zeolites and Amberlyst-15
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The liquid phase synthesis of methyl tert-butyl ether (MTBE) from methanol and isobutene over H-Beta and US-Y zeolite catalysts was studied in the temperature range 30-120°C. Up to 100°C, commercial H-Beta zeolite samples with small crystal size were more active than acid Amberlyst-15 (reference catalyst) and noticeably more active than US-Y, confirming results obtained under vapour phase conditions. The influence of methanol/isobutene (MeOH/IB) molar ratio, pressure, and space time on the conversion and MTBE selectivity was investigated. At optimized reaction conditions, MTBE yields of 85-90% can be reached with zeolite H-Beta as well as Amberlyst-15. On zeolites, side reactions of isobutene are more important than on Amberlyst-15, necessitating operation at MeOH/IB ratios higher than 1:1. For the same reason, at high conversion on H-Beta, the MTBE yields are more sensitive to contact time compared to Amberlyst-15. On H-Beta zeolite, no deactivation was observed during a period of more than 50 h on stream at 65°C, 1.4 MPa pressure, and a WHSV of 14 h-1. The catalytic activity of the zeolites is related to the external specific surface area, and to the concentration of bridging hydroxyls and silanol groups in the mesopores. A zeolite H-Beta sample with a Si/Al ratio of 36 has an optimum silanol and bridging hydroxyl content leading to stoichiometric methanol and isobutene adsorption, highest activity and MTBE yields.
- Collignon,Loenders,Martens,Jacobs,Poncelet
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- Development of the Late-Phase Manufacturing Process of ZPL389: Control of Process Impurities by Enhanced Process Knowledge
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The development of the late-phase manufacturing process of the drug candidate ZPL389 and the strategies for the control of impurities are outlined in detail. Selective salt formation at several stages was pivotal to controlling the process impurities. The extensive optimization of the N-methylation of a Boc-protected amine with dimethyl sulfate and of a nucleophilic aromatic substitution without the use of metal catalysts led to a robust, scalable process. The process was demonstrated on a >100 kg scale. Overall, improved drug substance quality, higher yield, and reduction of the process mass intensity were achieved.
- Santandrea, Ernesto,Waldraff, Christine,Gerber, Gilles,Moreau, Ma?l,Beney, Pascal
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p. 1190 - 1205
(2021/05/06)
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- Reactivity and Product Analysis of a Pair of Cumyloxyl and tert-Butoxyl Radicals Generated in Photolysis of tert-Butyl Cumyl Peroxide
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Alkoxyl radicals play important roles in various fields of chemistry. Understanding their reactivity is essential to applying their chemistry for industrial and biological purposes. Hydrogen-atom transfer and C-C β-scission reactions have been reported from alkoxyl radicals. The ratios of these two processes were investigated using cumyloxyl (CumO?) and tert-butoxyl radicals (t-BuO?), respectively. However, the products generated from the pair of radicals have not been investigated in detail. In this study, CumO? and t-BuO? were simultaneously generated from the photolysis of tert-butyl cumyl peroxide to understand the chemical behavior of the pair of radicals by analyzing the products and their distribution. Electron paramagnetic resonance and/or transient absorption spectroscopy analyses of radicals, including CumO? and t-BuO?, provide more information about the radicals generated during the photolysis of tert-butyl cumyl peroxide. Furthermore, the photoproducts of (3-(tert-butylperoxy)pentane-3-yl)benzene demonstrated that the ether products were formed in in-cage reactions. The triplet-sensitized reaction induced by acetophenone, which is produced from CumO?, clarified that the spin state did not affect the product distribution.
- Oyama, Ryoko,Abe, Manabu
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p. 8627 - 8638
(2020/07/21)
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- Catalytic etherification of alcohols in Shilov system: C[sbnd]O versus C[sbnd]H bond activation
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A novel catalytic reaction of alcohol etherification in the system ROH ? PtCl42? ‐ PtCl62? was found. Methanol easily transforms into dimethyl ether in the presence of catalytic amounts of PtII chloro complexes at 70?°C. Under the same conditions reaction of ethanol affords diethyl ether (catalytic) and π-ethylene PtII complex (stoichiometric). The reactions are accompanied by multiple H/D exchange, which is indicative of intermediacy of corresponding alkyl platinum derivatives. The plausible reaction mechanism involves oxidative addition of alcohol forming intermediate alkyl platinum(IV) derivative followed by decomposition of it via reductive elimination step under the action of alcohol giving the ether and regenerating catalyst. In the case of ethyl alcohol reaction, β-hydrogen abstraction from the intermediate Pt-ethyl species yields π-ethylene platinum(II) complex. Although it seems that the reaction does not involve the initial breaking of C[sbnd]H bonds of an alcohol, this system can be regarded as a model for studying of some peculiarities of Shilov chemistry, in particular, of isotope scrambling mechanisms in Shilov alkane activation. In contrast to reactions of dimethyl and diethyl ethers formation, tert-butyl ethers formation in CD3OH/t-BuOH medium is catalyzed by PtIV chloro complexes also and is not accompanied by isotope scrambling. These observations argue against intermediacy of alkyl platinum derivatives suggesting that acid-catalyzed mechanism operates in tert-butyl alcohol etherification.
- Khazipov, Oleg V.,Nykytenko, Denys V.,Krasnyakova, Tatyana V.,Vdovichenko, Alexander N.,Fuentes Frias, Dario A.,Mitchenko, Serge A.
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p. 490 - 498
(2016/12/16)
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- Methyl tert-butyl ether synthesis method
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The invention discloses a methyl tert-butyl ether synthesis method. The method comprises that according to a reaction mole ratio of 1: 1-4: 1, methanol and tert-butyl alcohol undergo a dehydration condensation reaction in the presence of an acidic catalyst and a dehydrant at a reaction temperature of 50-100 DEG C for 2-4h to produce a methyl tert-butyl ether crude product, and the crude product is purified through distillation to form high purity methyl tert-butyl ether. The synthesis method has mild conditions, can be operated simply, has economy and practicality and is suitable for large scale industrial production.
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Paragraph 0015
(2016/10/07)
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- METHOD FOR PRODUCING ASYMMETRIC ALKYL ETHER HAVING TERTIARY ALKYL GROUP
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PROBLEM TO BE SOLVED: To provide a method capable of obtaining an asymmetric alkyl ether having a tertiary alkyl group easily and industrially. SOLUTION: (1) There is provided a method for producing an asymmetric alkyl ether having a tertiary alkyl group by subjecting a tertiary alcohol and a primary alcohol or a secondary alcohol to a dehydration reaction using activated clay as a catalyst. (2) There is provided the method for producing an asymmetric alkyl ether having a tertiary alkyl group according to (1), where the tertiary alcohol is any one selected from the group consisting of tert-butanol, tert-amylalcohol and 1-adamantyl alcohol. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0018
(2017/01/31)
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- Process for the preparation of methyl tert-butyl ether and its device
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The invention relates to an ether production technology and especially relates to a method and production device for preparing methyl tertiary-butyl ether (MTBE) by a reaction of tertiary butanol and methanol. The method comprises that tertiary butanol and methanol are mixed and undergo a reaction to produce mixed gas, the mixed gas is fed into an extraction tower and is extracted, isobutene and MTBE are distilled off from the tower top, tertiary butanol, methanol, a trace amount of MTBE, water and an extractant flow out of the tower bottom, methanol is supplied for a tower top component of the extraction tower, the mixture is fed into a catalytic distillation tower, a methanol- and isobutene-containing tower top product of the catalytic distillation tower is fed back to a reactor and then undergoes a reaction, the MTBE is discharged from the bottom of the catalytic distillation tower, the materials discharged from the bottom of the catalytic distillation tower enters into a first extractant recovery tower, tertiary butanol, methanol and a trace amount of MTBE are distilled off from the top of the first extractant recovery tower, then are fed back to the reactor and then undergo a reaction, and the extractant and water flow out of the tower bottom, then enter into a second extractant recovery tower and then is recovered for recycle by reduced pressure distillation. The method and device solve the problem of azeotropy of tertiary butanol and water and improve a tertiary butanol one-step conversion rate to 87-94%.
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Paragraph 0044-0048
(2017/03/17)
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- High-conversion rate methyl tert-butyl ether preparation method
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The invention relates to a high-conversion rate methyl tert-butyl ether (MTBE) preparation method, and belongs to the technical field of preparation of MTBE. The preparation method comprises the following steps: 1, gasifying a tert-butyl alcohol and methanol mixed liquor, sending the gasified mixed liquor to a fixed bed reactor filled with a catalyst, carrying out a catalytic reaction, and condensing a gas phase generated through the reaction to obtain a condensate liquid; and 2, distilling the condensate liquid, collecting a 40-60 DEG C fraction, condensing the fraction, washing the condensed fraction with water, adding a water absorbing agent to the above separated ether layer to remove water, filtering out the water absorbing agent, adding metallic sodium to the ether layer, distilling the ether layer, and collecting a 54-56 DEG C fraction to obtain the product MTBE. The method for one-step synthesis of the MTBE from tert-butyl alcohol and methanol under the action of the catalyst has a high conversion rate.
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Paragraph 0018; 0019
(2017/04/29)
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- A process for the preparation of methyl tert-butyl ether
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The invention discloses a process for preparing methyl tertiary butyl ether. The process comprises the steps of immersing gamma-Al2O3 in a niobium oxalate solution, roasting a solid-phase material obtained after filtering, then dipping, drying and roasting the solid-phase material in a sulfuric acid solution, obtaining a niobium-containing solid acid catalyst, and filling a stainless steel fixed bed integral reactor full of the niobium-containing solid acid catalyst. A micro pump is used for pressing a mixed liquid of tertiary butanol and methyl alcohol in an evaporator for gasification, vapor enters the fixed bed integral reactor with a heat-insulating layer for catalytic reaction, and the methyl tertiary butyl ether can be obtained continuously after condensation of gaseous products. The selectivity of the methyl tertiary butyl ether obtained by the process is within a range of 81.6-82.3%, and the conversion rate of the tertiary butanol is within a range of 45.5-46.5%. Compared with the prior art, the process has the advantages that the niobium-containing solid acid catalyst is used for preparing the methyl tertiary butyl ether, the activity and the stability of the niobium-containing solid acid catalyst are higher than those of a resin catalyst, the niobium-containing solid acid catalyst can be recycled after regeneration, obtained products are stable in quality, good in selectivity, high in conversion rate and applicable to industrial production.
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Paragraph 0029; 0031
(2017/07/06)
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- A METHOD FOR CO-PRODUCING ISOBUTENE AND METHYL TERT-BUTYL ETHER BY USING TERT-BUTANOL MIXTURE
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This invention describes a method for co-producing isobutene and methyl tert-butyl ether in a catalytic distillation column, wherein contacting with solid acid catalysts the charged tert-butanol mixture undergoes dehydration and etherification. The mixture of isobutene and methyl tert-butyl ether withdrawn from the column top can be further separated, thus high purity isobutene and fuel-additive methyl tert-butyl ether are obtained.
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Page/Page column 12
(2016/10/08)
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- METHOD FOR COPRODUCING ISOBUTENE AND MTBE FROM TERT-BUTANOL MIXTURE IN A CATALYTIC DISTILLATION COLUMN
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This invention describes a method for co-producing isobutene and methyl tert-butyl ether in a catalytic distillation column, wherein contacting with solid acid catalysts the charged tert-butanol mixture undergoes dehydration and etherification. The mixture of isobutene and methyl tert-butyl ether withdrawn from the column top can be further separated, thus high purity isobutene and fuel-additive methyl tert-butyl ether are obtained.
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Paragraph 0030-0034
(2015/07/27)
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- Method for coproducing isobutene and MTBE from tert-butanol mixture in a catalytic distillation column
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This invention describes a method for co-producing isobutene and methyl tert-butyl ether in a catalytic distillation column, wherein contacting with solid acid catalysts the charged tert-butanol mixture undergoes dehydration and etherification. The mixture of isobutene and methyl tert-butyl ether withdrawn from the column top can be further separated, thus high purity isobutene and fuel-additive methyl tert-butyl ether are obtained.
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Page/Page column 7
(2015/11/30)
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- Synthesis and catalytic properties of ZSM-5 zeolite with hierarchical pores prepared in the presence of n-hexyltrimethylammonium bromide
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ZSM-5 samples with hierarchical pores (macropores, mesopores and micropores) were synthesized in the presence of n-hexyltrimethylammonium bromide (HTAB) and tetrapropylammonium hydroxide (TPAOH). The effect of synthesis conditions including the Si/Al ratio, crystallization temperature and time, and the amount of HTAB added to the synthesis system on the final products was examined. The catalytic properties of the hierarchical zeolite were investigated in reactions of Claisen-Schmidt condensation of benzaldehyde and acetophenone, self-condensation of cyclohexanone and methanol conversion. The hierarchical zeolite exhibits superior catalytic performance in Claisen-Schmidt condensation of benzaldehyde and acetophenone and self-condensation of cyclohexanone and has a remarkably high selectivity for dimethyl ether in the methanol conversion reaction at relatively low temperatures, which was attributed to the fast mass transport in the three-dimensional hierarchical pore network. A cooperative assembly mechanism accounting for the formation of the hierarchical zeolite was proposed based on experimental results.
- Bai, Peng,Wu, Pingping,Xing, Wei,Liu, Daolan,Zhao, Lianming,Wang, Youhe,Xu, Benjing,Yan, Zifeng,Zhao, Xiu Song
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p. 18586 - 18597
(2015/09/15)
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- Annulation of unsaturated silyl nitronates
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The intramolecular dipolar [3+2]-cycloaddition of acyclic δ,ε- and ε,ζ-unsaturated silyl nitronates was used in the stereoselective synthesis of functionalized cyclopentanone and cyclohexanone, respectively. The reaction with the γ,δ-unsaturated analog di
- Lozanova, A. V.,Zlokazov, M. V.,Veselovsky, V. V.
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p. 696 - 700
(2015/02/05)
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- Synthesis of alkyl methyl ethers and alkyl methyl carbonates by reaction of alcohols with dimethyl carbonate in the presence of tungsten and cobalt complexes
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Alkyl methyl ethers and alkyl methyl carbonates were synthesized by reaction of alcohols with dimethyl carbonate in the presence of tungsten and cobalt carbonyls. Optimal reactant and catalyst ratios, as well as reaction conditions, were found for selective formation of alkyl methyl ethers or alkyl methyl carbonates.
- Khusnutdinov,Shchadneva,Mayakova
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p. 790 - 795
(2014/08/18)
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- FUSED AMINODIHYDROTHIAZINE DERIVATIVES
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The present invention relates to a fused aminodihydrothiazine derivative of formula (I): wherein X is hydrogen or fluorine; R is monofluoromethyl or difluoromethyl; and pharmaceutically acceptable salts thereof; which compound has an Aβ production inhibitory effect or a BACE1 inhibitory effect and is useful as a prophylactic or therapeutic agent for a neurodegenerative disease caused by Aβ and typified by Alzheimer-type dementia.
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Page/Page column
(2014/07/08)
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- Rhodium-carbon bond energies in Tp′Rh(CNneopentyl)(CH2X)H: Quantifying stabilization effects in M-C bonds
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A series of substituted methyl derivatives of the type Tp′ Rh(CNneopentyl)(CH2X)H (CH2X = CH2C(i - O)CH3, CH2Ci - CCH3, CH 2O-t-Bu, CH2CF3, CH2F, CHF 2) was synthesized either by photolysis of Tp′Rh(CNneopentyl) (PhNCNneopentyl) in neat CH3X or by exchange with the labile hydrocarbon in Tp′Rh(CNneopentyl)(n-pentyl)H or Tp′Rh(CNneopentyl) (CH3)H. Only a single product was observed in each case. Clean reductive elimination was observed for all compounds in C6D 6. Structures of these complexes and their corresponding chlorinated derivatives have been characterized by NMR spectroscopy, elemental analysis, and X-ray crystallography. Relative Rh-C bond energies are calculated using previously established kinetic techniques, and two separate linear correlations are observed versus known C-H bond strengths, one for the parent hydrocarbons, and one for the substituted hydrocarbons. Both correlations have slopes of 1.4, and are separated vertically by 7.5 kcal mol-1 (-CH2X above -CxHy). In addition, it is now clear that preferences for linear vs branched olefin insertion products in substituted derivatives can be predicted on the basis of the strengths of the β-C-H bonds. The DFT calculations of the metal-carbon bond strengths in these Rh-CH2X derivatives with α-substitution show a trend that is in good agreement with the experimental results.
- Jiao, Yunzhe,Evans, Meagan E.,Morris, James,Brennessel, William W.,Jones, William D.
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p. 6994 - 7004
(2013/06/27)
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- Entropies of organolithium aggregation based on measured microsolvation numbers
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The recent measurement (J. Am. Chem. Soc.2008, 130, 14179-14188) of the microsolvation numbers of monodentate, nonchelating ethereal donor ligands coordinating to the monomers and dimers of two sterically shielded =C(aryl)-Li compounds permits the determination of well-founded dimerization enthalpies (ΔH0) and entropies (ΔS0) from properly formulated equilibrium constants, which must include the concentrations of the free donor ligands. The monomers are found to dimerize endothermically (ΔH0 > 0) in [D8]toluene solution in the presence of the donor tBuOMe or THF, but only slightly exothermically (ΔH 0 = -0.5 kcal per mol of dimer) with the donor Et2O. The dimerization entropies ΔS0 (in cal mol-1 K -1) with the respective equivalents of released donor ligands are 7.2 and 11.0 (with 2 equiv of tBuOMe in the two cases), 6.1 (with 2 Et 2O), and 34.1 (with 4 THF). It is shown that the improper omission of microsolvation from the equilibrium constant (a usual practice when the ligand numbers are not known) can lead to contaminated aggregation entropies ΔSψ, which may deviate considerably from the true entropies ΔS0. A method is provided for estimating the required microsolvation numbers from 13C/Li NMR coupling constants 1JC,Li for less congested organolithium types whose coordinated and free donor ligands cannot be distinguished by NMR integration.
- Knorr, Rudolf,Menke, Thomas,Ferchland, Kathrin
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supporting information
p. 468 - 472
(2013/03/28)
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- PROCESS FOR PREPARING AN EPOXIDE FROM AN OXYGENATE
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The invention relates to an integrated process for preparing an epoxide from an oxygenate, wherein the production of a lower olefin from the oxygenate and the subsequent epoxidation of the lower olefin is combined and wherein isobutene, a by-product of the lower olefin production, is converted into a hydroperoxide that is used for the conversion of the lower olefin into the corresponding epoxide.
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Page/Page column 9
(2013/05/09)
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- Oxidizing properties of the tert-butyl hydroperoxide-tetra-tert- butoxychromium system
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tert-Butyl hydroperoxide reacts with the tetra-tert-butoxychromium by oxidizing the latter to chromyl CrV=O (C6H6, 20 C). At t-BuOOH-Cr(OBu-t)4 ratio of 2: 1 or higher, oxygen is released. The occuring processes include the formation of chromium-containing peroxides and peroxytrioxydes. The t-BuOOH-Cr(OBu-t)4 system oxidizes aromatic hydrocarbons of various structures (anthracene, 9,10-dimethylanthracene, 1,1-diphenylethylene, alkylarenes), as well as primary and secondary alcohols. Depending on the structure of the substrate, the oxidants are: in situ generated oxygen including that in the singlet state, peroxy radicals, or chromium-containing peroxides.
- Stepovik,Potkina,Poddelskii
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p. 2005 - 2017
(2014/01/17)
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- LACTONE PHOTOACID GENERATORS AND RESINS AND PHOTORESISTS COMPRISING SAME
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New lactone-containing photoacid generator compounds (“PAGs”) and photoresist compositions that comprise such PAG compounds are provided. These photoresist compositions are useful in the manufacture of electronic devices
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- CATALYTIC REACTION-RECTIFICATION INTEGRATED PROCESS AND SPECIALIZED DEVICE THEREOF
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A catalytic reaction-rectification integrated process and a catalytic reaction-rectification integrated column (T-01), the specialized device of such process. The process comprises that the reactants are preheated and mixed with catalysts, and then fed into a jet agitation reaction section (6) located in the middle of the catalytic reaction-rectification integrated column (T-01) from a feeding inlet. The jet agitation reaction section (6) is a kettle-like reactor located in the middle of the catalytic reaction-rectification integrated column (T-01). After pressurized by a centrifugal pump (21), the reactant materials are admitted into a subsonic or transonic agitator (33) located within the reaction section (6). The reactant materials are ejected into the jet agitation reaction section (6) at high speed, to efficiently mix the solid and liquid phases in the reaction section (6) and to reinforce heat and mass transfer efficiency during the reaction. The liquid reaction mixture is separated and purified directly in the catalytic reaction-rectification integrated column (T-01). This process may be used for esterification, the production of alcohols from olefins and water, and the production of ethers from olefins and alcohols.
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Page/Page column 5
(2011/06/26)
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- Cascade catalysis for the homogeneous hydrogenation of CO2 to methanol
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This communication demonstrates the homogeneous hydrogenation of CO 2 to CH3OH via cascade catalysis. Three different homogeneous catalysts, (PMe3)4Ru(Cl)(OAc), Sc(OTf) 3, and (PNN)Ru(CO)(H), operate in sequence to promote this transformation.
- Huff, Chelsea A.,Sanford, Melanie S.
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supporting information; experimental part
p. 18122 - 18125
(2012/01/04)
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- CO-CRYSTALS AND PHARMACEUTICAL FORMULATIONS COMPRISING THE SAME
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An immediate release formulation of an active ingredient.
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- PROCESS FOR PRODUCING SEC-BUTYLBENZENE
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In a process for producing sec-butylbenzene, a C4 olefinic hydrocarbon feedstock comprising isobutene and at least one n-butene is contacted with methanol and/or water in the presence of an acid catalyst to selectively oxygenate isobutene to produce an effluent stream rich in n-butene and containing less isobutene than the feedstock. The effluent stream is then contacted with benzene under alkylation conditions and in the presence of an alkylation catalyst to produce alkylation stream comprising sec-butylbenzene.
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Page/Page column 14
(2010/04/28)
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- TARGETED ANTIMICROBIAL MOIETIES
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This invention provides novel targeted antimicrobial compositions. In various embodiments chimeric moieties are provided comprising an antimicrobial peptide attached to a peptide targeting moiety that binds a bacterial strain or species.
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- Stabilization of the collagen triple helix by O-methylation of hydroxyproline residues
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This invention relates to a collagen polypeptide comprising a tripeptide motif having the formula (ProYaaGly)n, where Yaa is an O-methylated amino acid residue and “n” is the number of motif repeats. Preferred O-methylated amino acid residues at the Yaa position include (2S,4R)-4-methoxyproline. Other suitable amino acid residues at that position include O-mono or O-di-halogenated methylproline. Also, disclosed is a method of making a synthetic or a semi-synthetic collagen polypeptide molecule having increased stability relative to natural collagen. The strengthened collagen molecules are suitable for use in biomaterials for the medical field or in leather-related products prepared by the tanning industry.
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- Gas-phase catalytic synthesis of MTBE from MeOH and ButOH over-various microporous n H-zeolites
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Several H-zeolites such as HZSM-5, HY, Hss, H-13X, H-K10 and HA have been used to catalyze the gas-phase synthesis of methyl tert-butyl ether from methanol and tert-butanol in a continuous fixed-bed reactor. The ascending sequence of Broensted acidity is: H-K10 (0.86) 10 (0.87) 10 (150 °C) ? H-13X (220 °C), and is dependent on several factors. The Hss catalyst shows the best activity and on-stream stability (the selective conversion of >97.4 mol% Bu'OH to MTBE) at 80-90 °C (comparable to that of commercial Amberlyst-15), along with increasing time-on-stream up to 110 h at 90 °C. The highly selective conversion of Bu'OH to MTBE remains more or less constant on both the catalysts.
- Zhang,Xia,Lu,Ma,Su
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experimental part
p. 788 - 792
(2010/03/25)
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- Ferric perchlorate as an efficient and useful catalyst for the selective benzylation and methylation of alcohols with benzyl chloride and methyl iodide
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A mild and efficient method was developed for selective benzylation and methylation of hydroxyl compounds in the presence of a catalytic amount of ferric perchlorate. We showed that ferric perchlorate was very effective in selectively promoting the benzylation and methylation of primary aliphatic and benzylic alcohols versus secondary aliphatic alcohols and phenolic hydroxy groups. Graphical abstract: [Figure not available: see fulltext.]
- Behbahani, Farahnaz K.,Heravi, Majid M.,Oskooie, Hossien A.
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experimental part
p. 181 - 184
(2010/03/26)
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- Hydrogen bonding lowers intrinsic nucleophilicity of solvated nucleophiles
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The relationship between nucleophilicity and the structure/environment of the nucleophile is of fundamental importance in organic chemistry. In this work, we have measured nucleophilicities of a series of substituted alkoxides in the gas phase. The functional group substitutions affect the nucleophiles through ion-dipole, ion-induced dipole interactions and through hydrogen bonding whenever structurally possible. This set of alkoxides serves as an ideal model system for studying nucleophiles under microsolvation settings. Marcus theory was applied to analyze the results. Using Marcus theory, we separate nucleophilicity into two independent components, an intrinsic nucleophilicity and a thermodynamic driving force determined solely by the overall reaction exothermicity. It is found that the apparent nucleophilicities of the substituted alkoxides are always much lower than those of the unsubstituted ones. However, ion-dipole, ion-induced dipole interactions, by themselves, do not significantly affect the intrinsic nucleophilicity; the decrease in the apparent nucleophilicity results from a weaker thermodynamic driving force. On the other hand, hydrogen bonding not only stabilizes the nucleophile but also increases the intrinsic barrier height by 3 to ~4 kcal mol-1. In this regard, the hydrogen bond is not acting as a perturbation in the sense of an external dipole but more directly affects the electronic structure and reactivity of the nucleophilic alkoxide. This finding offers a deeper insight into the solvation effect on nucleophilicity, such as the remarkably lower reactivities in nucleophilic substitution reactions in protic solvents than in aprotic solvents.
- Chen, Xin,Brauman, John I.
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scheme or table
p. 15038 - 15046
(2009/03/12)
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- Process for preparation of methyl methacrylate using recycled methanol
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The invention relates to a process for production of methacrylic acid, to a process for production of methyl methacrylate comprising the process steps a) providing a feed composition comprising at least one C4 feed compound selected from isobutylene and tertiary butanol; b) providing methanol; c) subjecting the at least one C4 feed compound and the methanol to a first catalytic reaction zone to obtain a reaction phase comprising methyl tertiary butyl ether; d) separating at least a first part of methanol from the reaction phase to obtain a first methanol phase and a reaction phase depleted in methanol; e) subjecting at least one of the reaction phase and the reaction phase depleted in methanol to a second catalytic reaction zone to obtain a splitting phase comprising isobutylene and methanol; f) optionally separating at least a first part of isobutylene from the second reaction phase to obtain a first isobutylene phase and a splitting phase depleted in isobutylene; g) optionally subjecting the first isobutylene phase to a first purification zone; h) subjecting the optionally purified first isobutylene phase to a third catalytic reaction zone to obtain an oxidation phase comprising at least one C4 oxidation product selected from methacrolein and methacrylic acid; i) optionally subjecting the oxidation phase to a second purification zone; j) subjecting the optionally purified oxidation phase to a fourth catalytic reaction zone to obtain an esterification phase comprising methyl methacrylate; k) optionally subjecting the esterification phase to a third purification zone, to an apparatus for production of methacrylic acid, to an apparatus for production of methyl methacrylate, to a process carried out in the apparatus, to methacrylic acid, to methyl methacrylate, to methacrylate esters, to a process for preparation of a polymer comprising at least one methacrylic acid, methyl methacrylate and/or methacrylate ester monomer unit, to a polymer comprising at least one methacrylic acid, methyl methacrylate and/or methacrylate ester monomer, to a process for preparation of a composition, to a composition, to chemical products, and to the use of at least one of methacrylic acid, methyl methacrylate, methacrylate ester, a polymer and/or a composition in chemical products.
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Page/Page column 15-16
(2009/01/20)
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- Multistage catalytic process for olefin etherification
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A process for producing ethers by reacting alcohols and olefins in successive catalytic stages is disclosed. The process includes alternating catalytic reaction stages and separation stages.
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Page/Page column 3
(2008/06/13)
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- Method for preparing phenyl acetic acid derivatives
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Method for preparing (S)(+)phenyl acetic acid derivatives having the general formula (I): wherein R1 is a linear or branched alkyl group with 1-6 carbon atoms or substituted benzyl group, and R2 is methyl, ethyl or propyl group said method, characterised in that a compound of the general formula (II): wherein R1 is as given above, and R3 is a nucleofuge, or a suitable salt of a compound of the general formula (II) is reacted with a compound having the general formula (III): wherein R2 is as given above, and R4 is hydrogen or a nucleofuge that can be removed hydrolytically, and the protective group R4 that may be present, may be subsequently removed hydrolytically.
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- PROCESS FOR PRODUCTION OF OPTICALLY ACTIVE PPAR-ACTIVATING COMPOUND AND INTERMEDIATE OF THE SAME
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A process for obtaining a compound (1) and an intermediate thereof in high yield and high optical yield is provided. A process for producing a compound (4), the process including reacting a compound (2) with a compound (3) in the presence of a base; and a process for producing a compound (1), the process including reacting a compound (2) with a compound (3) in the presence of a base to yield a compound (4) and then deesterifying the compound (4). wherein R represents an alkyl group having 1 to 6 carbon atoms or an aralkyl group having 7 to 8 carbon atoms.
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- Photochromic materials having extended pi-conjugated systems and compositions and articles including the same
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Various non-limiting embodiments disclosed herein relate to photochromic materials having extended pi-conjugated systems. For example, various non-limiting embodiments disclosed herein provide a photochromic material, such as an indeno-fused naphthopyran, which comprises a group that extends the pi-conjugated system of the indeno-fused naphthopyran bonded at the 11-position thereof. Further, the photochromic materials according to certain non-limiting embodiments disclosed herein may display hyperchromic absorption of electromagnetic radiation as compared to conventional photochromic materials and/or may have a closed-form absorption spectrum that is bathochromically shifted as compared to conventional photochromic materials. Other non-limiting embodiments relate to photochromic compositions and photochromic articles, such as optical elements, made using the disclosed photochromic materials, and methods of making the same.
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- Oxidation of monohydric and dihydric alcohols with CCl4 catalyzed by molybdenum compounds
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Mo(CO)6 catalyzed oxidation of alcohols and diols with tetrachloromethane. Primary oxidation products in reaction of alcohols with CCl4 are alkyl hypochlorites, and final products depending on the structure of initial alcohol are aldehydes (as acetals), ketones, chloroketones, and esters.
- Khusnutdinov,Shchadneva,Burangulova,Muslimov,Dzhemilev
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p. 1615 - 1621
(2007/10/03)
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- METHOD FOR PRODUCING BUTENE OLIGOMERS AND TERT-BUTYL ETHERS FROM C4 FLOWS CONTAINING ISOBUTENE
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The invention relates to a method for producing butene oligomers and tert-butyl ethers from C4 hydrocarbon flows, by converting isobutene into butene oligomers and tert-butyl ethers and removing the same from the C4 flows.
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Page/Page column 30-31
(2008/06/13)
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- Carboxylic acid amides, the preparation thereof, and their use as pharmaceutical compositions
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The present invention relates to new substituted carboxylic acid amides of general formula wherein A, B and R1 to R5 are defined as in claim 1, the tautomers, the enantiomers, the diastereomers, the mixtures thereof and the salts thereof, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases, which have valuable properties. The compounds of the above general formula I as well as the tautomers, the enantiomers, the diastereomers, the mixtures thereof and the salts thereof, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases, and their stereoisomers have valuable pharmacological properties, particularly an antithrombotic activity and a factor Xa-inhibiting activity.
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- METHOD FOR PRODUCING OLIGOMERS DERIVED FROM BUTENES
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The invention relates to a method for producing oligomers, primarily consisting of repeating units, derived from 1 or 2-butene, from a hydrocarbon stream that essentially consists of branched and linear hydrocarbon compounds with 4 carbon atoms and contains olefinically branched and linear hydrocarbon compounds with 4 carbon atoms (parent stream C4). According to said method, a) the parent stream C4 is split into a fraction that primarily consists of linear hydrocarbon compounds with 4 carbon atoms (fraction I-C4) and a fraction that primarily consists of branched hydrocarbon compounds with 4 carbon atoms (fraction v-C4) by bringing the parent stream C4 into contact with a membrane, which allows the passage of linear hydrocarbon compounds with 4 carbon atoms more easily than branched hydrocarbon compounds with 4 carbon atoms, b) the olefinic hydrocarbon compounds with 4 carbon atoms contained in the fraction I-C4 are oligomerised, after the optional separation of butanes, c) the olefinic hydrocarbon compounds with 4 carbon atoms contained in the fraction v-C4 are subjected to one of the following steps: c1) reaction with methanol to form methyl-tert-butylether; c2) hydroformylation to essentially form isovaleraldehyde; c3) polymerisation to form polyisobutylene; c4) dimerisation to form 2,4,4-trimethyl-1-pentene; c5) alkylation to essentially form saturated hydrocarbon compounds with 8 or 9 carbon atoms.
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Page/Page column 9-10
(2008/06/13)
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- Thermostable sulfated 2-4 nm tetragonal ZrO2 with high loading in nanotubes of SBA-15: A superior acidic catalytic material
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The high-loaded (48-60 wt.%) 2-4 nm tetragonal ZrO2 phase inserted in mesostructured silica SBA-15 by chemical solution decomposition (CSD) of Zr(n-PrO)4 and activated at 873 K displayed ~ 3 times higher capacity for surface sulfate ions and, respectively, 1.5-2.2 times higher catalytic activity per gram of SO4-ZrO2/SBA-15 composite in condensation of MeOH with t-BuOH and dehydration of isopropanol compared with the regular bulk sulfated zirconia material.
- Landau,Titelman,Vradman,Wilson
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p. 594 - 595
(2007/10/03)
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- Novel alkyl/aryl hydroxy or keto thiepine compounds as inhibitors of apical sodium co-dependent bile acid transport (ASBT) and taurocholate uptake
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Thiepine apical sodium co-dependent bile acid transport (ASBT) inhibitors are disclosed together with methods of making the same, methods of using the same to treat hyperlipidemic conditions as well as pharmaceutical compositions containing the same compounds.
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- Process for preparing highly pure raffinate II and Methyl tert-butyl ether
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The present invention provides a process, which includes: contacting at least one C4-hydrocarbon stream which includes isobutene with methanol over at least one acid catalyst and preparing methyl tert-butyl ether (MTBE) and a substantially isobutene-free C4-hydrocarbon mixture; wherein in a first stage in one or more first reactors, the isobutene reacts with the methanol over an acid catalyst to form an equilibrium mixture which includes MTBE, remaining isobutene and methanol; the equilibrium mixture is fed to a second stage which includes a reactive distillation column; and in the reactive distillation column, the remaining isobutene reacts with methanol over an acid ion exchange resin to form MTBE; wherein the reactive distillation column is operated at a pressure ranging from 3 to 15 bar abs., a reaction zone temperature ranging from 55° C. to 75° C., and a reflux ratio of less than 1. The present invention also provides a method of making gasoline, which includes the above process and contacting the MTBE with a fuel.
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Page column 9-11
(2008/06/13)
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- The first non-acid catalytic synthesis of tert-butyl ether from tert-butyl alcohol using ionic liquid as dehydrator
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Methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and isopropyl tert-butyl ether (IPTBE) have been synthesized for the first time over a non-acid ionic liquid as catalyst and dehydrator with high conversion (> 90%) and selectivity (> 90%) under mild conditions.
- Shi, Feng,Xiong, Hai,Gu, Yanlong,Guo, Shu,Deng, Youquan
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p. 1054 - 1055
(2007/10/03)
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- Process for preparing indolopyrrolocarbazole derivatives, intermediates therefor, and preparation process of the intermediates
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This invention relates to a process for preparation of an indolopyrrolocarbazole derivative [I] by treating a compound [V] with a base in an inert solvent to prepare a compound [IV], reacting the obtained compound [IV] with a compound [III] to prepare a compound [II] and then removing the protective groups of the compound [II], the preparation intermediates compound [II], compound [III] and compound [IV], and processes for preparation of the compound [III]. wherein Y1 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, a benzyloxymethyl group or an aralkyl group, R1, R2, R3, R4, R5 and R6 may be the same or different and each represent a protective group of a hydroxyl group, R7 and R8 may be the same or different and each represent a hydrogen atom or a protective group of a hydroxyl group, and X represents an acid molecule.
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- Method for conducting exothermic reactions
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A process for oligomerization of C4and C5 isoolefins or the etherification thereof with C1to C6alcohols wherein the reactants are contacted first in a partial liquid phase reactor (boiling point reactor) with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300° F., at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized and the entire reaction stream is directed to a catalytic distillation column reactor for further reaction of the reactants, where the improvement is having a decoupling drum between the boiling point reactor and the catalytic distillation column reactor. The addition of a decoupler drum allows the reactors to operate at a pressure independent of each other.
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- Amide compounds and pharmaceutical compositions for inhibiting protein kinases, and methods for their use
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Amide compounds that modulate and/or inhibit the activity of certain protein kinases are described. These compounds and pharmaceutical compositions containing them are capable of mediating tyrosine kinase signal transduction in order to modulate and/or inhibit unwanted cell proliferation. The invention is also directed to the therapeutic or prophylactic use of pharmaceutical compositions containing such compounds, and to methods of treating cancer as well as other disease states associated with unwanted angiogenesis and/or cellular proliferation, such as diabetic retinopathy, neovascular glaucoma, rheumatoid arthritis, and psoriasis, by administering effective amounts of such compounds.
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- Process for producing optically active 3,3,3-Trifluoro-2-Hydroxy-2-Methylpropionic acid, and salt thereof
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There are disclosed are a diastereomer salt of formula (1): a process for producing the same, a process for producing optically active 3,3,3-trifluoro-2-hydroxy-2-methylpropionic acid of formula (2′): a novel optically active amine compound of formula (4): a novel optically active amine compound of formula (8): an imine compound of formula (7) or (11):
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- Method for the preparation of tetrahydrobenzothiepines
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Among its several embodiments, the present invention provides an improved process for the preparation of tetrahydrobenzothiepine-1,1-dioxide compounds; the provision of a process for preparing a diastereomeric mixture of tetrahydrobenzothiepine-1,1-dioxide compounds from a single diastereomer of such compounds; the provision of a process for the preparation of 3-bromo-2-substituted propionaldehyde compounds; and the provision of a process for the preparation of 3-thio-2-substituted propionaldehyde compounds.
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- Process for preparing alkyl ethers and mixtures thereof
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The invention relates to a process for preparing tertiary alkyl ethers, in particular MTBE, ETBE or mixtures of these ethers with heavier ethers. According to the process the feedstock containing hydrocarbons is fed to a catalytic distillation reactor system, in which the isoolefines, in particular the C4 to C7 isoolefines, of the feed are reacted with an alkanol in the presence of a cation exchange resin in order to produce tertiary alkyl ether products. The reaction product containing the ethers is removed from the distillation system as the bottoms product and, if necessary, it is subjected to an additional treatment for producing a gasoline component. The unreacted alkanol is removed as the overhead product of the distillation. According to the invention, the distillate withdrawn mainly contains an azeotrope of C3 hydrocarbons and alkanol, the C3 amount of which at least approximately corresponds to the C3 hydrocarbon concentration of the hydrocarbon feed, a substantial amount of the unreacted alkanol being removed in the form of said azeotrope. By means of the invention the need for a separate alkanol washing unit is eliminated in the apparatus which considerably reduces apparatus investment costs.
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Page column 10-11
(2008/06/13)
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