- Direct Synthesis of Dimethyl Carbonate from Carbon Dioxide and Methanol at Room Temperature Using Imidazolium Hydrogen Carbonate Ionic Liquid as a Recyclable Catalyst and Dehydrant
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The direct synthesis of dimethyl carbonate (DMC) from CO2 and CH3OH was achieved at room temperature with 74 % CH3OH conversion in the presence of an imidazolium hydrogen carbonate ionic liquid ([CnCmIm][HCO3]). Experimental and theoretical results reveal that [CnCmIm][HCO3] can transform quickly into a CO2 adduct, which serves as an effective catalyst and dehydrant. Its dehydration ability is reversible. The energy barrier of the rate-determining step for the DMC synthesis is only 21.7 kcal mol?1. The ionic liquid can be reused easily without a significant loss of its catalytic and dehydrating ability.
- Zhao, Tianxiang,Hu, Xingbang,Wu, Dongsheng,Li, Rui,Yang, Guoqiang,Wu, Youting
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- Metal-free imidazolium hydrogen carbonate ionic liquids as bifunctional catalysts for the one-pot synthesis of cyclic carbonates from olefins and CO2
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A direct route for the synthesis of cyclic carbonates from olefins and CO2 has been achieved by using imidazolium hydrogen carbonate ionic liquids ([CnCmIm][HCO3]) as bifunctional catalysts in the absence of a solvent. [CnCmIm][HCO3] can convert into a carbene-CO2 adduct spontaneously. The HCO3- anion and carbene-CO2 can serve as catalysts for olefin epoxidation and CO2 cycloaddition, respectively, which obviously simplifies the synthesis of cyclic carbonates. The reaction proceeds quite well under mild conditions. This cheap and simple method can be applied to various olefins with good to excellent yields of cyclic carbonates. The catalyst can be easily recycled at least four times without significantly losing its catalytic activity.
- Liu, Jia,Yang, Guoqiang,Liu, Ying,Wu, Dongsheng,Hu, Xingbang,Zhang, Zhibing
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supporting information
p. 3834 - 3838
(2019/07/31)
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- Preparation method of antibacterial veterinary medicine quinocetone
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The invention provides a preparation method of quinocetone which is a national first class new veterinary medicine initiated internationally and has antibacterial, diarrhea-stopping and growth-promoting effects. The preparation method comprises the following steps: adding alkaline ionic liquid into a reactor, adding benzofurazan and benzylidene acetylacetone, stirring, conducting reaction at room temperature, and performing aftertreatment on the reaction liquid after the reaction to obtain the quinocetone. The method is short in process step, mild in reaction condition, short in reaction time, high in efficiency, high in product yield and high in product purity; meanwhile, the alkaline ionic liquid provided by the invention is in a liquid state at room temperature, has high dissolubility on the raw materials and can serve as a catalyst and a reaction solvent of a reaction system, so that environmental pollution caused by an organic solvent is avoided and large-scale production is facilitated.
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Paragraph 0012
(2017/08/29)
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- Preparation method of 3,4,5-trimethoxy-3',4'-dimethoxy chalcone
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The invention provides a preparation method of 3,4,5-trimethoxy-3',4'-dimethoxy chalcone. 3,4-dimethoxyacetophenone and 3,4,5-trimethoxy benzaldehyde are dissolved into strongly basic ionic liquid; room-temperature stirring is performed; after the reaction is completed, still standing is performed on the reaction liquid; filtering, water washing and drying are performed to obtain the 3,4,5-trimethoxy-3',4'-dimethoxy chalcone. The preparation method has the advantages that the reaction conditions are mild; the requirements on the reaction equipment are low; the reaction cost is reduced; the pollution of an organic solvent on the environment is effectively avoided; the large-scale production is convenient; the yield and the purity of the product obtained by the method are high; the reaction efficiency is greatly improved.
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Paragraph 0013
(2017/07/20)
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- BMIm HCO3: an ionic liquid with carboxylating properties. Synthesis of carbamate esters from amines
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1-Butyl-3-methylimidazolium hydrogen carbonate (BMIm HCO3) was used as an ionic liquid with carboxylating properties able to convert, in the presence of an alkyl halide, amines into the corresponding carbamate esters. Moderate to good yields of
- Di Nicola,Arcadi,Rossi
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supporting information
p. 9895 - 9898
(2016/12/07)
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- Method for preparing fructosazine by utilizing chitin-based biomass
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The invention relates to a method for preparing fructosazine by utilizing chitin-based biomass. The method comprises the following steps: adding a dry chitin-based biomass raw material, an imidazolium ionic liquid solution and an additive to dimethyl sulfoxide to obtain a mixture; uniformly mixing the obtained mixture to perform a reaction, wherein the mass ratio of the imidazolium ionic liquid to the chitin-based biomass raw material is 1: (2-100), and the mass ratio of the added chitin-based biomass raw material to an oxidant is 1: (1-50) to obtain an intermediate product; adding a crystallization solvent to the intermediate product, wherein the volume ratio of the intermediate product to the solvent is 1: 1 to 1: 10; completely dissolving the product; removing undissolved impurities to obtain a filter liquor; carrying out rotary evaporation concentration on the filter liquor; standing; and recrystallizing to prepare the final product. The method has the advantages of wide raw material resources, no pollution, simple preparation and high product purity.
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Paragraph 0044; 0045; 0047; 0048
(2016/10/07)
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- Estimation and structural effect on physicochemical properties of alkylimidazolium-based ionic liquids with different anions
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Ten kinds of alkylimidazolium-based aprotic ionic liquids (AILs) with hydrogen carbonate, dihydrogen phosphate, and hydrogen sulfate anions were prepared, and methods of elemental analysis, infrared spectroscopy, and proton nuclear magnetic resonance were employed to characterize the ILs, respectively. Properties such as electrical conductivity, density, dynamic viscosity, surface tension, were measured and correlated with thermodynamic and empirical equations over various temperature ranges under ambient conditions. Some significant thermodynamic parameters of the ILs were estimated. The trends of changing with temperature for the dynamic viscosity and the electrical conductivity were described by the Vogel-Fulcher-Tamman equation. The activation energies of dynamic viscosity and electrical conductivity were also calculated. Further, the structures and the energetics of the ILs ions were obtained through combining density functional theory calculations and the COSMO-RS methodology. The structural effects of ion variation on the properties of the ILs were studied.
- Zhang, Qingguo,Lan, Yalin,Liu, Hongwei,Zhang, Xinyuan,Zhang, Xuelei,Wei, Ying
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p. 2002 - 2012
(2016/07/06)
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- Method for preparing deoxyfructosazine through chitin biomass
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A method for preparing deoxyfructosazine through chitin biomass comprises the following steps: uniformly mixing a dry chitin biomass raw material, an imidazole ionic liquid solution and an additive in a dimethyl sulfoxide reaction medium for reaction to obtain an intermediate product; adding a crystal solvent in the intermediate product to completely dissolve the product, performing hot filtration to remove insoluble impurities, performing rotary evaporation concentration on a filtrate, and performing recrystallization to obtain the product, namely the deoxyfructosazine. The method has the advantages that the raw material source is wide, pollution is avoided, the preparation is simple, and the product purity is high.
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Paragraph 0044; 0047
(2017/01/26)
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- Insights on recyclable catalytic system composed of task-specific ionic liquids for the chemical fixation of carbon dioxide
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A series of imidazolium-based ionic liquids (ILs) were synthesised and used as single component and metal-free homogeneous catalysts to convert a renewable, inexpensive and non-toxic CO2 feedstock into useful products. The cycloaddition of carbon dioxide to epoxides to produce cyclic carbonate was evaluated. A detailed investigation was carried out on a variety of factors that affected the reactivity and selectivity, such as the catalyst structures (nature of cation and anion). The effect of reaction parameters (temperature, reaction time, CO2 uptake and catalyst amount) on the catalytic performance was also investigated in detail. High conversions and selectivities could be achieved under mild pressure condition (5 bar) using 1-n-butyl-3-methylimidazolium bromide. A synergetic effect of the acidic and basic sites as well as suitable hydrogen-bonding strength is considered crucial for the reaction to proceed smoothly. This protocol was found to be applicable to a disubstituted epoxide. Furthermore, the straightforward synthesis of cyclic carbonates by direct oxidative carboxylation from olefins was achieved using only 1-n-butyl-3-methylimidazolium bromide as a catalyst. the Partner Organisations 2014.
- Girard, Anne-Lise,Simon, Nathalia,Zanatta, Marcileia,Marmitt, Sandro,Goncalves, Paulo,Dupont, Jairton
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p. 2815 - 2825
(2014/05/06)
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- Ascorbic acid based ionic liquids: Recyclable and efficient catalytic systems for the huisgen cycloaddition
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A new method for the Huisgen cycloaddition using an ascorbic acid based ionic liquid and a copper catalyst in an ionic liquid, under microwave irradiation, is described. The reaction times are short and a simple procedure for separation of the products is
- Koguchi, Shinichi,Nakamura, Kaori
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p. 2305 - 2309
(2013/11/06)
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- Ionic liquids as benign catalysts for the carbonylation of amines to formamides
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1-Butyl-3-methylimidazolium hydrogen carbonate ([BMIm][HCO3]), prepared from the reaction of [BMIm]Cl with K2CO3 in methanol, exhibits high activity for the carbonylation of amines to produce formamides. Computational calculation results on the carbonylation reaction of methylamine implies that such high activity of [BMIm][HCO3] could be ascribed to the bi-functional actions of [HCO3]- as a hydrogen atom acceptor and a donor.
- Choi, Young-Seop,Shim, Yu Na,Lee, Jeesun,Yoon, Jung Hee,Hong, Chang Seop,Cheong, Minserk,Kim, Hoon Sik,Jang, Ho Gyeom,Lee, Je Seung
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experimental part
p. 87 - 92
(2012/02/05)
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- METHOD FOR PRODUCING HETEROCYCLIC QUATERNARY AMMONIUM AND/OR GUANIDINIUM COMPOUNDS
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The invention relates to a method for producing an intermediate product containing a heterocyclic quarternary ammonium and/or guanidium cation, for the synthesis of heterocyclic quaternary ammonium and/or guanidium compounds. According to said method, heterocyclic quaternary ammonium and/or guanidium carboxylates are oxidised with an oxidising agent in the presence of a metal from groups 8 to 10 of the periodical table, at a temperature of between 0 and 250 °C and a pressure of between 0.05 and 20 MPa abs.
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Page/Page column 33
(2008/06/13)
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- Imidazole carbenes
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A process for the preparation of imidazolium carbenes of formula (I) wherein R1 and R2 which can be the same or different, are hydrogen or linear or branched hydrocarbyl groups comprising heating an imidazolium halide with a strong base under reduced pressure and separating the resultant products is described. Also described is a process for the preparation of salts of these imidazolium carbenes, and their use as ionic liquids.
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