- Thermokinetics of reactions with liquid-liquid phase separation
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Isothermal heat flow calorimetry with controlled thermoelectric cooling resp. heating is applied to study the critical slowing down of the kinetics of reactions with liquid-liquid phase separation. Results (i) on the acid-catalysed hydrolysis of chloromethyloxirane by water, and (ii) on the ring-opening and esterification of bromomethyloxirane by dichloroacetic acid in the presence of cyclohexane as an inert solvent, both at 298.15 K, are presented. The heat production w(t) which is proportional to the reaction rate ?ζ/?t (where ζ, is the reaction coordinate) exhibits a funnel-like fall-off when the reaction path intersects the binodal curve at the critical solution point CP. From the shape of this part of the w(t) curves an average value of the critical exponent Φ = 0.72±0,003, which refers to the change of ζ with t at constant T and p, is calculated. This result is to be compared with the theoretical value of Φ = 0.708 obtained from a modification of the Griffiths and Wheeler theory of critical points in multicomponent systems to chemically reacting systems far from equilibrium by introducing f as an additional extensive variable. This allows the critical slowing down of the reaction rates to be interpreted as resulting from the divergence of the correlation length ζ, resp. from the convergence of the transport phenomena to zero at the CP. ? VCH Verlagsgesellschaft mbH, 1996.
- Baumann, Christian,Becker, Friedrich
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Read Online
- Curing Behavior and Properties of Sustainable Furan-Based Epoxy/Anhydride Resins
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The last two decades have witnessed a significant growth in using bioderived materials, driven by the necessity of replacing fossil-derived precursors, reducing the fossil fuel consumption, and lowering the global environmental impact. This is possible thanks to the availability of abundant resources from biomasses and the development of optimized technologies based on the principles of sustainability and circular economy. Herein, we report on the synthesis and characterization of new carbohydrate-derived epoxy resins. In particular, 2,5-bis[(oxiran-2-ylmethoxy)methyl]furan has been synthesized and cured with methyl nadic anhydride. The effect of different initiators was studied, in order to identify the most efficient curable formulations. A series of resins was then prepared varying the epoxide-anhydride ratios. The results gathered from physicochemical, mechanical, morphological analyses have demonstrated that the produced furan-based thermosets have the potential to be proposed as sustainable alternatives to the traditional, bisphenol A-containing epoxy resins.
- Marotta, Angela,Faggio, Noemi,Ambrogi, Veronica,Cerruti, Pierfrancesco,Gentile, Gennaro,Mija, Alice
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Read Online
- Selective synthesis of epichlorohydrin: Via liquid-phase allyl chloride epoxidation over a modified Ti-MWW zeolite in a continuous slurry bed reactor
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The epoxidation of allyl chloride (ALC) to epichlorohydrin (ECH) with H2O2 using a piperidine (PI)-modified Ti-MWW catalyst (Ti-MWW-PI) in a continuous slurry reactor was investigated to develop an efficient reaction system for the corresponding industrial process. The reaction parameters, including solvent, reaction temperature, t-butanol/ALC mass ratio, ALC/H2O2 molar ratio, weight hourly space velocity of H2O2, and the addition amount of ammonia, were studied in detail to pursue high H2O2 conversion and ECH selectivity. A long catalytic lifetime of 244 h was achieved at high H2O2 conversion (>97.0%) and ECH selectivity (>99.8%) under optimized reaction conditions. The crystallinity was well maintained for the deactivated Ti-MWW-PI catalyst, which was regenerated by a combination of calcination and piperidine treatment. This journal is
- Ding, Luoyi,Yin, Jinpeng,Tong, Wen,Peng, Rusi,Jiang, Jingang,Xu, Hao,Wu, Peng
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p. 331 - 342
(2021/01/11)
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- Method for producing 3-chloro-1,2-propylene glycol by using acetic anhydride-modified graphene oxide
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The invention relates to a method for producing 3-chloro-1,2-propylene glycol by using an acetic anhydride-modified graphene oxide catalyst. The method comprises the following steps: using solid acetic anhydride-modified graphene oxide (AGO) as a catalyst, adding hydrochloric acid and glycerol into a reaction kettle, performing heating to 50-110 DEG C in a nitrogen atmosphere, performing stirringreaction for 2-10 hours, performing cooling to 30-60 DEG C, centrifugally separating the catalyst and a reaction solution, and rectifying the reaction liquid under reduced pressure to obtain a product3-chloro-1,2-propylene glycol shown in a formula (I). The method is simple in process, and the catalyst can be recycled. The conversion rate of the reactant glycerol can reach 95% or above, and the selectivity of the product 3-chloro-1,2-propylene glycol can reach 80% or above.
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Paragraph 0014-0017
(2021/02/10)
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- In situconstruction of phenanthroline-based cationic radical porous hybrid polymers for metal-free heterogeneous catalysis
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Rational design of multifunctional radical porous polymers with redox activity for targeted metal-free heterogeneous catalysis is an important research topic. In this work, we reported a new class of phenanthroline-based cationic radical porous hybrid polymers (Phen˙+-PHPs), which were constructed from the Heck reaction between a newly designed dibromo-substituted phenanthroline ionic monomer (iDBPhen) and a rigid building block, octavinylsilsesquioxane (VPOSS). For the first time, the stable phenanthroline-based radical cation was unexpectedly discovered in these polyhedral oligomeric silsesquioxane (POSS)-based porous hybrid polymers, probably undergoingin situreduction of the dicationic monomer iDBPhen during the alkaline reagent K2CO3-involved Heck reaction. The radical characters of the typical porous polymers Phen˙+-PHP-2 and Phen˙+-PHP-2Br were confirmed from the electron paramagnetic resonance (EPR) spectra and X-ray photoelectron spectra (XPS). The chemical structures and porous geometry were fully characterized by a series of advanced technologies. Surprisingly, the metal-free cationic radical polymer Phen˙+-PHP-2 exhibited high heterogeneous catalytic efficiency in the H2O2-mediated selective oxidation of various sulfides to sulfoxides with high yields under mild conditions, owing to the electron-accepting and redox ability of Phen-based dications and radical cations. Moreover, the extended sample Phen˙+-PHP-2Br prepared by post-treatment of Phen˙+-PHP-2 with aqueous HBr was also employed as a metal-free efficient heterogeneous catalyst in the conversion of CO2with epoxides into cyclic carbonates under atmospheric pressure and low temperatures. The remarkable catalytic performance in CO2conversion should be assigned to the synergistic catalysis of POSS-derived Si-OH groups and nucleophilic Br?anions and N active atom-involved Phen cationic radical moieties within Phen˙+-PHP-2Br. These two catalysts can be facilely recovered and reused, also with stable recyclability in the above catalytic reaction systems, achieving the heterogeneous catalytic demands for multipurpose reactions.
- Chen, Guojian,Zhang, Yadong,Liu, Ke,Liu, Xiaoqing,Wu, Lei,Zhong, Hu,Dang, Xuejing,Tong, Minman,Long, Zhouyang
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supporting information
p. 7556 - 7565
(2021/04/06)
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- Preparation method for 1,3-propylene glycol from glycerol
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The invention relates to a preparation method for 1,3-propylene glycol from glycerol, wherein the preparation method comprises the steps of chlorohydrination reaction, cyclization reaction, hydrogenation reaction and the like. The glycerin conversion rate of the preparation method reaches 99% or above, the yield of 1,3-propylene glycol reaches 65% or above, and the preparation method has the advantages of being simple in process, mild in reaction condition, small in investment, high in technical safety and easy to operate and control.
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Paragraph 0066-0076
(2021/04/10)
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- Sterically controlling 2-carboxylated imidazolium salts for one-step efficient hydration of epoxides into 1,2-diols
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In order to overcome the disadvantages of excessive water and many byproducts in the conventional process of epoxide hydration into 1,2-diols, 2-carboxylated imidazolium salts were first adopted as efficient catalysts for one-step hydration of epoxides into 1,2-diols. By regulating the cation chain lengths, different steric structures of 2-carboxylated imidazolium salts with chain lengths from C1 to C4 were prepared. The salt with the shortest substituent chain (DMIC) exhibited better thermal stability and catalytic performance for hydration, achieving nearly 100% ethylene oxide (EO) conversion and 100% ethylene glycol (EG) selectivity at 120 °C, 0.5 h with just 5 times molar ratio of H2O to EO. Such a tendency is further confirmed and explained by both XPS analysis and DFT calculations. Compared with other salts with longer chains, DMIC has stronger interaction of CO2?anions and imidazolium cations, exhibiting a lower tendency to release CO2?and form HO-CO2?, which can nucleophilically attack and synergistically activate ring-opening of epoxides with imidazolium cations. The strong huge sterically dynamic structure ring-opening transition state slows down the side reaction, and both cations and anions stabilized the transition state imidazolium-EG-HO-CO2?, both of which could avoid excessive hydration into byproducts, explaining the high 1,2-diol yield. Based on this, the cation-anion synergistic mechanism is then proposed.
- Cheng, Weiguo,Dong, Li,Fu, Mengqian,Su, Qian,Tan, Xin,Yao, Xiaoqian,Ying, Ting,Zhang, Suojiang
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p. 2992 - 3000
(2021/05/07)
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- Hydrogen-Catalyzed Acid Transformation for the Hydration of Alkenes and Epoxy Alkanes over Co-N Frustrated Lewis Pair Surfaces
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Hydrogen (H2) is widely used as a reductant for many hydrogenation reactions; however, it has not been recognized as a catalyst for the acid transformation of active sites on solid surface. Here, we report the H2-promoted hydration of alkenes (such as styrenes and cyclic alkenes) and epoxy alkanes over single-atom Co-dispersed nitrogen-doped carbon (Co-NC) via a transformation mechanism of acid-base sites. Specifically, the specific catalytic activity and selectivity of Co-NC are superior to those of classical solid acids (acidic zeolites and resins) per micromole of acid, whereas the hydration catalysis does not take place under a nitrogen atmosphere. Detailed investigations indicate that H2 can be heterolyzed on the Co-N bond to form Hδ-Co-N-Hδ+ and then be converted into OHδ-Co-N-Hδ+ accompanied by H2 generation via a H2O-mediated path, which significantly reduces the activation energy for hydration reactions. This work not only provides a novel catalytic method for hydration reactions but also removes the conceptual barriers between hydrogenation and acid catalysis.
- Deng, Qiang,Deng, Shuguang,Gao, Ruijie,Li, Xiang,Tsang, Shik Chi Edman,Wang, Jun,Zeng, Zheling,Zou, Ji-Jun
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p. 21294 - 21301
(2021/12/17)
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- Novel method for producing 2-amino-1, 3-propylene glycol by JIT method
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The invention belongs to the field of fine chemical engineering, and relates to a novel method for producing 2-amino-1, 3-propylene glycol by a JIT method, the novel method is composed of a catalytic chlorination reaction and a catalytic amination reaction, glycerol is chlorinated by hydrogen chloride under the catalysis of zinc chloride to obtain 2-chloro-1, 3-propylene glycol, and the 2-chloro-1, 3-propylene glycol is subjected to a catalytic reaction by urotropin to obtain 2-chloro-1, 3-propylene glycol.
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Paragraph 0042-0047
(2021/11/26)
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- Continuous flow upgrading of glycerol toward oxiranes and active pharmaceutical ingredients thereof
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A robust continuous flow procedure for the transformation of bio-based glycerol into high value-added oxiranes (epichlorohydrin and glycidol) is presented. The flow procedure features a central hydrochlorination/dechlorination sequence and provides economically and environmentally favorable conditions involving an organocatalyst and aqueous solutions of hydrochloric acid and sodium hydroxide. Pimelic acid (10 mol%) shows an exceptional catalytic activity (>99% conversion of glycerol, a high selectivity toward 1,3-dichloro-2-propanol and 81% cumulated yield toward intermediate chlorohydrins) for the hydrochlorination of glycerol (140 °C) with 36 wt% aqueous HCl. These conditions are validated on a sample of crude bio-based glycerol. The dechlorination step is effective (quantitative conversion based on glycerol) with concentrated aqueous sodium hydroxide (20 °C) and can be directly concatenated to the hydrochlorination step, hence providing a ca. 2:3 separable mixture of glycidol and epichlorohydrin (74% cumulated yield). An in-line membrane separation unit is included downstream, providing usable streams of epichlorohydrin (in MTBE, with an optional concentrator) and glycidol (in water). The scalability of the dechlorination step is then assessed in a commercial pilot-scale continuous flow reactor. Next, bio-based epichlorohydrin is further utilized for the continuous flow preparation of β-amino alcohol active pharmaceutical ingredients including propranolol (hypertension, WHO essential), naftopidil (prostatic hyperplasia) and alprenolol (angina pectoris) within a concatenable two-step procedure using a FDA class 3 solvent (DMSO). This work provides the first example of direct upgrading of bio-based glycerol into high value-added pharmaceuticals under continuous flow conditions.
- Morodo, Romain,Gérardy, Romaric,Petit, Guillaume,Monbaliu, Jean-Christophe M.
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p. 4422 - 4433
(2019/08/21)
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- Carboxylate ionic liquid as well as preparation method and application thereof
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The invention provides carboxylate ionic liquid as well as a preparation method and application thereof. According to the carboxylate ionic liquid provided by the invention, an imidazole group or a pyridine group is introduced into the cationic part of the carboxylate ionic liquid and a carboxylic acid group is introduced into the anionic part of the carboxylate ionic liquid; and the ionic liquidcatalyst provided by the invention is simple and convenient in synthesis route, high in yield and easy to recover. Anion carboxylate radical in the carboxylate ionic liquid provided by the invention serves as an active site, so that synthesis of diol can be realized through high-efficiency and high-selectivity catalysis of hydration reaction of epoxy compounds under the condition of not adding other catalysts.
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Paragraph 0166-0170; 0204-0207
(2019/10/23)
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- Synthesis of covalent organic frameworks via in situ salen skeleton formation for catalytic applications
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Covalent organic frameworks (COFs) with highly ordered crystalline structures and uniform microenvironments have potential applications in the field of catalysis; however, their application is restricted by their harsh synthesis conditions and multi-step synthetic procedures. Herein, we report the facile synthesis of a new COF-salen via in situ salen skeleton formation by heating aldehyde and amine precursors in an air atmosphere. This COF-salen possesses an AA stacking eclipsed layered crystalline structure, micro/macro hierarchical pores, and high stability in acid or base medium and can be efficiently transformed to COF-salen-M (M = Co, Mn, Cu, Zn) with a well-retained ordered crystalline structure. The successful application of COF-salen-Co(iii) and COF-salen-Mn, respectively, in epoxide hydration, which requires the cooperation of two salen-Co(iii), and olefin epoxidation, in which the isolated salen-Mn functions as the active site, can be attributed to their unique layered crystalline structures; these structures can efficiently isolate the active sites by restricting their mobility and generate cooperation between nearby active sites in adjacent layers. COF-salen-Co exhibited much higher activity and stability than the corresponding amorphous polymers in cycloaddition reactions of epoxides with CO2, demonstrating the advantage of the crystalline structure in catalysis.
- Li, He,Feng, Xiao,Shao, Pengpeng,Chen, Jian,Li, Chunzhi,Jayakumar, Sanjeevi,Yang, Qihua
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p. 5482 - 5492
(2019/03/13)
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- Laminaria digitata and palmaria palmata seaweeds as natural source of catalysts for the cycloaddition of CO2 to Epoxides
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Seaweed powder has been found to act as an effective catalyst for the fixation of CO2 into epoxides to generate cyclic carbonates under solvent free conditions. Model background reactions were performed using metal halides and amino acids typically found in common seaweeds which showed potassium iodide (KI) to be the most active. The efficacy of the seaweed catalysts kelp (Laminaria digitata) and dulse (Palmaria palmata) was probed based on particle size, showing that kelp possessed greater catalytic ability, achieving a maximum conversion and selectivity of 63.7% to styrene carbonate using a kelp loading of 80% by weight with respect to epoxide, 40 bar of CO2, 120?C for 3 h. Maximizing selectivity was difficult due to the generation of diol side product from residual H2O found in kelp, along with a chlorinated by-product thought to form due to a high quantity of chloride salts in the seaweeds. Data showed there was loss of organic matter upon use of the kelp catalyst, likely due to the breakdown of organic compounds and their subsequent removal during product extraction. This was highlighted as the likely cause of loss of catalytic activity upon reuse of the Kelp catalyst.
- Comerford, James W.,Gray, Thomas,Lie, Yann,Macquarrie, Duncan J.,North, Michael,Pellis, Alessandro
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- Effect of sodium chloride on the solubility and hydrolysis of epichlorohydrin in water
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The mutual solubility of the components in the epichlorhydrin–water–sodium chloride system was studied in the temperature range of 20–90 °С. It was found that epichlorohydrin is salted out as the concentration of NaCl increases. The Sechenov coefficient was determined to be equal to 0.29. It was found that epichlorohydrin reacts with an aqueous solution of sodium chloride to form glycerol dichlorohydrins. Alkali formed during this reaction catalyzes the hydrolysis of epichlorohydrin to glycerol monochlorohydrin, acts as a reagent in the glycidol formation and accelerates its subsequent conversion to glycerol.
- Dmitriev,Zanaveskin,Khadzhiev
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p. 1627 - 1630
(2018/11/21)
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- Process for producing dimethyl carbonate
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The present disclosure relates to a recycling method for producing dimethyl carbonate. The process is unique in that it produces a by-product that can be re-used in the process as a raw material for repeating the process. For example, when the process is directed to synthesizing dimethyl carbonate, glycerol is used as a starting material. Glycerol is also a by-product produced during formation of dimethyl carbonate, and therefore it can be re-used as starting material to generate more dimethyl carbonate.
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Page/Page column 9
(2017/06/15)
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- Multivariate Metal-Organic Frameworks as Multifunctional Heterogeneous Asymmetric Catalysts for Sequential Reactions
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The search for versatile heterogeneous catalysts with multiple active sites for broad asymmetric transformations has long been of great interest, but it remains a formidable synthetic challenge. Here we demonstrate that multivariate metal-organic frameworks (MTV-MOFs) can be used as an excellent platform to engineer heterogeneous catalysts featuring multiple and cooperative active sites. An isostructural series of 2-fold interpenetrated MTV-MOFs that contain up to three different chiral metallosalen catalysts was constructed and used as efficient and recyclable heterogeneous catalysts for a variety of asymmetric sequential alkene epoxidation/epoxide ring-opening reactions. Interpenetration of the frameworks brings metallosalen units adjacent to each other, allowing cooperative activation, which results in improved efficiency and enantioselectivity over the sum of the individual parts. The fact that manipulation of molecular catalysts in MTV-MOFs can control the activities and selectivities would facilitate the design of novel multifunctional materials for enantioselective processes.
- Xia, Qingchun,Li, Zijian,Tan, Chunxia,Liu, Yan,Gong, Wei,Cui, Yong
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supporting information
p. 8259 - 8266
(2017/06/28)
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- A safer and greener chlorohydrination of allyl chloride with H2O2 and HCl over hollow titanium silicate zeolite
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Industrial production of dichloropropanols through chlorohydrination of allyl chloride suffers from a series of disadvantages such as use of hazardous Cl2, low atom economy, low dichloropropanol concentration and serious pollution. In this work, a safer and greener route for chlorohydrination of allyl chloride with H2O2 and HCl over hollow titanium silicate (HTS) at mild condition is developed. Unlike the traditional Cl2-based chlorohydrination, this novel method is initiated via synergistic effect of Lewis acidity (HTS) and Br?nsted acidity (HCl) to promote occurrence of oxidation, protonation and nucleophilic reaction of allyl chloride simultaneously and hence dichloropropanols are generated. Owing to a completely different reaction route, the formation of 1,2,3-trichloropropane by-product is depressed and the content of dichloropropanol exceeded 22?wt%, which increase by about 4 times compared with traditional Cl2-based chlorohydrination (the content of dichloropropanol is below 4?wt%). At the optimized conditions, both of the allyl chloride conversion and dichloropropanol selectivity could approach 99% simultaneously and the waste is minimized. What's more, the HTS was reusable. Concentrated HCl solution treatment was adopted to test HTS's stability. The characterization and catalytic evaluation results reveal that, although parts of the framework Ti species have transformed into non-framework Ti and then leached into the solution, HTS remains structural stable, and the allyl chloride conversion and dichloropropanol selectivity didn't decrease obviously during the treatment.
- Peng, Xinxin,Xia, Changjiu,Lin, Min,Shu, Xingtian,Zhu, Bin,Wang, Baorong,Zhang, Yao,Luo, Yibin,Mu, Xuhong
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- Method for synthesizing 3-chloro-1,2-propylene glycol
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The invention discloses a method for synthesizing 3-chloro-1,2-propylene glycol. Sulfamic acid as a catalyst, water as a reaction medium and epichlorohydrin as a raw material are subjected to a catalysis hydrolysis reaction. The requirements for temperatures in the reaction process are low, the conversion rate is high, few harmful impurities are contained, no corrosion is caused to production equipment, the product purity is up to 99.5% or above, and no color change is caused after long-time storage.
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Paragraph 0013; 0014; 0015; 0016; 0017; 0018; 0019
(2017/10/07)
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- Asymmetric Hydrolytic and Aminolytic Kinetic Resolution of Racemic Epoxides using Recyclable Macrocyclic Chiral Cobalt(III) Salen Complexes
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New chiral macrocyclic cobalt(III) salen complexes were synthesized and used as catalyst for the asymmetric kinetic resolution (AKR) of terminal epoxides and glycidyl ethers with aromatic/aliphatic amines and water as nucleophiles. This is the first occasion where a Co(III) salen complex demonstrated its ability to catalyze AKR as well as hydrolytic kinetic resolution (HKR) reactions. Excellent enantiomeric excesses of the epoxides, the corresponding amino alcohols and diols (upto 99%) with quantitative yields were achieved by using the chiral Co(III) salen complexes in dichloromethane at room temperature. This protocol was further extended for the synthesis of two important drug molecules, i.e., (S)-propranolol and (R)-naftopidil. The catalytic system was also explored for the synthesis of chirally pure diols and chiral cyclic carbonates using carbon dioxide as a greener renewable C1 source. The catalyst was recycled for upto 5 catalytic cycles with retention of enantioselectivity. (Figure presented.).
- Tak, Rajkumar,Kumar, Manish,Menapara, Tusharkumar,Gupta, Naveen,Kureshy, Rukhsana I.,Khan, Noor-ul H.,Suresh
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supporting information
p. 3990 - 4001
(2017/11/22)
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- Chlorohydrination of allyl chloride with HCl and H2O2 catalyzed by hollow titanium silicate zeolite to produce dichloropropanol
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Overall, over 95% of epichlorohydrin is industrially manufactured via the chlorohydrination route with hazardous Cl2 as a reagent, which brings serious operation and pollution problems. Herein, we describe a novel Cl2-free process for the synthesis of dichloropropanols from allyl chloride with H2O2 and HCl catalyzed by hollow titanium silicate zeolite under mild conditions. A high conversion and overall dichloropropanol selectivity exceeding 95% are simultaneously achieved, and the heterogeneous catalyst is highly stable and amenable for reuse. Comprehensive experimental and spectroscopic data suggest that the Lewis acidity of the framework Ti species has a synergistic effect with the Br?nsted acidity of HCl that promotes the epoxidation of allyl chloride and the ring opening of the epoxy groups.
- Peng, Xinxin,Xia, Changjiu,Lin, Min,Yuan, Hui,Zhu, Bin,Zhang, Yao,Wang, Baorong,Shu, Xingtian
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supporting information
p. 1221 - 1225
(2017/08/15)
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- Ionic Polymer Microspheres Bearing a CoIII-Salen Moiety as a Bifunctional Heterogeneous Catalyst for the Efficient Cycloaddition of CO2and Epoxides
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We report a unique strategy to obtain the bifunctional heterogeneous catalyst TBB-Bpy@Salen-Co (TBB=1,2,4,5-tetrakis(bromomethyl)benzene, Bpy=4,4'-bipyridine, Salen-Co=N,N'-bis({4-dimethylamino}salicylidene)ethylenediamino cobalt(III) acetate) by combining a cross-linked ionic polymer with a CoIII-salen Schiff base. The catalyst showed extra high activity for CO2fixation under mild, solvent-free reaction conditions with no requirement for a co-catalyst. The synthesized catalyst possessed distinctive spherical structural features, abundant halogen Br-anions with good leaving group ability, and accessible Lewis acidic Co metal centers. These unique features, together with the synergistic role of the Co and Br-functional sites, allowed TBB-Bpy@Salen-Co to exhibit enhanced catalytic conversion of CO2into cyclic carbonates relative to the corresponding monofunctional analogues. This catalyst can be easily recovered and recycled five times without significant leaching of Co or loss of activity. Moreover, based on our experimental results and previous work, a synergistic cycloaddition reaction mechanism was proposed.
- Leng, Yan,Lu, Dan,Zhang, Chenjun,Jiang, Pingping,Zhang, Weijie,Wang, Jun
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p. 8368 - 8375
(2016/06/13)
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- A kind of glycerin method of preparing dichlorohydrine chloride
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The invention relates to a method of preparing dichloropropanol by glycerol chlorination, belonging to the field of application of biomas glycerol. The method comprises the following step of: by using a hydrogen chloride gas as a chlorinating agent, by using malic acid, citric acid and lactic acid as a catalyst to catalyze glycerol chlorination to prepare the dichloropropanol. The material glycerol adopted by the method disclosed by the invention is cheap in price, and chloridized to have important industrial significance in developing downstream products. Hydroxyl carboxylic acid is easy to obtain and does not need further treatment; while being used as the catalyst for chlorination, the hydroxyl carboxylic acid has no pollution to environment, is high in catalytic activity, simple in process, gentle in reaction condition, less in dosage of the catalyst and less in reaction byproducts.
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Paragraph 0021-0023
(2017/05/12)
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- Epoxides hydration on CoIII(salen)-OTs encapsulated in silica nanocages modified with prehydrolyzed TMOS
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The silylation for reducing the pore entrance size is crucial for the success encapsulation of molecular catalysts. Herein, we reported the preparation of an efficient solid catalyst for epoxide hydration via encapsulation of CoIII(salen)-OTs in the nanocages of FDU-12 using prehydrolyzed tetramethylorthosilicate (TMOS) as silylation reagent under mild condition. CoIII(salen)-OTs in nanocages could afford TOF of 2760 h-1 in the hydration of propylene epoxide (PO), which is the highest ever reported at low PO/H2O molar ratio. Comparison of the activity of CoIII(salen)-OTs accommodated in nanocages with different microenvironments suggests that CoIII(salen)-OTs in hydrophilic microenvironment was more active than that in hydrophobic microenvironment in the hydration of propylene epoxide. Moreover, studies show that the deactivation rate of CoIII(salen)-OAc is lower than that of CoIII(salen)-OTs in nanocages due to the confinement effect of the nanoreactor.
- Zhong, Mingmei,Zhao, Yaopeng,Yang, Qihua,Li, Can
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p. 184 - 191
(2016/04/04)
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- Enhancement of Catalytic Activity in Epoxide Hydration by Increasing the Concentration of Cobalt(III)/Salen in Porous Polymer Catalysts
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The rational design of catalytic materials from the reaction characteristics is expected to be a useful strategy to create highly efficient catalysts. Herein, according to a well-established reaction pathway of epoxide hydration catalyzed a dual-molecular system of Co3+/salen in which a high concentration of active sites is favorable to enhance the activity, we provide an alternative way to prepare a highly efficient heterogeneous catalyst with a high concentration of Co3+/salen from the polymerization of vinyl-functionalized salen monomers followed by the loading of Co3+ species (Co3+/POL-salen). Co3+/POL-salen has a hierarchical porosity and an extraordinary hydrothermal stability. Importantly, catalytic tests in epoxide hydration demonstrate that Co3+/POL-salen affords excellent high activities, which are even better than those of the homogeneous version. This phenomenon is related to the very high concentration of Co3+/salen in the catalyst. In addition, this catalyst can be recycled readily because of its excellent hydrothermal stability.
- Dai, Zhifeng,Sun, Qi,Chen, Fang,Pan, Shuxiang,Wang, Liang,Meng, Xiangju,Li, Jixue,Xiao, Feng-Shou
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p. 812 - 817
(2016/03/05)
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- Epoxide hydrolysis and alcoholysis reactions over crystalline Mo-V-O oxide
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Crystalline Mo-V-O oxides have been used as a catalyst for the hydrolysis and alcoholysis of propylene oxide to diols and ethers, respectively. Relationships between the active crystal facet, the acidity of Mo-V-O catalysts and the activity have been established. Our results indicate that the a-b plane is the active facet for the hydrolysis reaction.
- Zhang, Xiaochen,Wang, Min,Zhang, Chaofeng,Lu, Jianmin,Wang, Yehong,Wang, Feng
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p. 70842 - 70847
(2016/08/05)
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- Lewis Acid Catalysis Confined in Zeolite Cages as a Strategy for Sustainable Heterogeneous Hydration of Epoxides
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We report a heterogeneous catalysis strategy to the sustainable hydration of epoxides by designing robust Lewis acid catalysts confined in zeolite cages as natural shape-selective nanoreactors. In the case of ethylene oxide hydration, Sn-H-SSZ-13 zeolite exhibits remarkable catalytic performance, with an ethylene oxide conversion above 99% and a monoethylene glycol selectivity above 99%, at approaching stoichiometric water/ethylene oxide ratios and near-ambient reaction temperatures. It is revealed by theoretical studies that partially hydroxylated Sn species are the preferred Lewis acid sites for the hydration of ethylene oxide. The concept of Lewis acid catalysis confined in zeolite cages may be applied in the future in the chemical industry to develop energy-saving and environmentally benign processes.
- Dai, Weili,Wang, Chuanming,Tang, Bo,Wu, Guangjun,Guan, Naijia,Xie, Zaiku,Hunger, Michael,Li, Landong
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p. 2955 - 2964
(2016/07/06)
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- A process for the preparation of amino-glycerol
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The invention belongs to the chemical field, particularly relates to a production and synthesis technology of a medical intermediate, and provides a preparation method of 3-amino-1,2-propanediol mainly aiming at a 3-amino-1,2-propanediol product. The preparation method of 3-amino-1,2-propanediol adopts epichlorohydrin and ammonia water as the main raw materials, a two-component catalyst is used in a hydrolysis reaction process and an ammoniation reaction process respectively, the reaction temperature in earlier period and later period in a hydrolysis reaction kettle is increased in a segmented manner, the reaction selectivity is improved, side effects are reduced, the reaction rate is increased, the reaction time is shortened, and energy consumption is reduced. The specific operation flow of the preparation method comprises the hydrolysis reaction, neutralization, distillation, ammoniation reaction, filtering, distillation, centrifugation and rectification. Meanwhile, the catalyst can be recycled and the cost can be saved, and the preparation method further has the advantages of high safety, stable product quality, high purity and the like.
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Paragraph 0017; 0018; 0021; 0022
(2017/02/09)
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- A simplified early stage assessment of process intensification: Glycidol as a value-added product from epichlorohydrin industry wastes
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The present work deals with the production of glycidol through a new synthetic approach based on the conversion of 2-chloro-1,3-propanediol (β-MCH), a by-product in the epichlorohydrin production plant. β-MCH was converted with high yield (90%) and selectivity (99%) to glycidol using an alcoholic solution of KOH at room temperature in only 30 minutes. A simplified early stage assessment based on the use of the green metrics and a life cycle analysis were adopted in order to evaluate the environmental feasibility of this innovative route if compared with the traditional chain to epichlorohydrin. The waste recovery and the maximization of the overall process efficiency lead to sensible reductions per each indicator considered in the assessment, suggesting the possibility of developing on a full industrial scale. In addition, in order to verify the potentialities behind the substitution of the fossil-based glycidol with the product resulted from the recovery of the β-MCH, a cradle-to-gate analysis and the GREENMOTION tool were adopted.
- Cespi,Cucciniello,Ricciardi,Capacchione,Vassura,Passarini,Proto
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supporting information
p. 4559 - 4570
(2016/08/18)
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- PROCESS FOR HYDROGENATING DICHLOROISOPROPYL ETHER
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Convert dichloroisopropyl ether into a halogenated derivative by contacting the dichloroisopropyl ether with a source of hydrogen and a select heterogeneous hydrogenation catalyst under process conditions selected from a combination of a temperature within a range of from 50 degrees centigrade (oC) to 350 oC, a pressure within a range of from atmospheric pressure (0.1 megapascals) to 1000 pounds per square inch (6.9 MPa), a liquid feed volume flow to catalyst mass ratio between 0.5 and 10 L/Kg*h and a volume hydrogen / volume liquid ratio between 100 and 5000 ml gas/ ml liquid. The halogenated derivative is at least one of 1-chloro-2-propanol and 1,2-dichloropropane 1, and glycerin monochlorohydrin.
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Page/Page column 6
(2016/04/20)
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- A modified L-shaped molecular sieve catalytic glycerin method of preparing dichlorohydrine chloride
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The invention provides a method for preparing dichloropropanol by modified L-type molecular sieve catalyst-catalytic chlorination of glycerin. Biodiesel by-product glycerin and HCl gas as raw materials undergo a reaction at a temperature of 110-140 DEG C in the presence of a self-made modified L-type molecular sieve catalyst to produce dichloropropanol. The method for preparing dichloropropanol has a low raw material cost, mild reaction conditions, less side products and high industrial application values. Through use of the modified L-type molecular sieve LaHL-5 catalyst prepared by crystallization at a crystallization temperature of 120 DEG C for crystallization time of 96h, after a chlorination reaction at a temperature of 130 DEG C for 10h, a total dichloropropanol yield is 95.87%.
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Paragraph 0025-0028
(2017/03/18)
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- PROCESS FOR THE PRODUCTION OF DICHLOROHYDRONS
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This invention is related to the process of dichlorohydrins production starting from glycerol by hydrochlorination with hydrochloric acid in the presence of a new class of catalysts consisting in the acyl chlorides.
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Page/Page column 25; 26
(2015/03/28)
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- CONVERSION OF GLYCERINE TO DICHLOROHYDRINS AND EPICHLOROHYDRIN
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The present invention relates to a process for the production of dichlorohydrin by catalyzed hydrochlorination of glycerine where the reaction is performed in at least two subsequent stages operating continuously at different pressures with both vapor and liquid recycle. The first reactor, low pressure (L. P.) reactor, operating at a pressure ranging from 1 to 4 bar and at a temperature from 900C to 1300C converts most of GLY to MHC. The second reactor, medium pressure (M. P. ) reactor, operating at a pressure ranging from 5 to 20 bar and at temperature from 90 °c to 1300C converts the effluent from the L. P. reactor to DCH with an adequate degree of conversion. Each reactor is followed by a stripping unit.
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Paragraph 0078-0081; 0084-0087
(2017/01/02)
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- PROCESS FOR MANUFACTURING AN EPOXIDE
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Process for manufacturing an epoxide by reacting at least one chlorohydrin with at least one dehydrochlorinating agent in order to give the epoxide and at least one chlorinated co-product, said process comprising regenerating the dehydrochlorinating agent from the chlorinated co-product by a treatment which does not comprise an electrolysis operation.
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Page/Page column 26-30
(2015/07/07)
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- A convenient method for producing mono- and dichlorohydrins from glycerol
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A new method for the transformation of glycerol into mono- and dichlorohydrins has been studied. With trimethylchlorosilane as chlorinating agent and acetic acid as catalyst, mono- and dichlorohydrins have been obtained in high yields and selectivity. In fact, under different reaction conditions, the synthesis of α-monochlorohydrin (3-chloropropan-1,2-diol) or α,γ-dichlorohydrin (1,3-dichloropropan-2-ol) as predominant product has been achieved. This process was also exploited for the valorisation of the crude mixture of glycerol and monochlorohydrin (glyceric mixture), a by-product from an earlier BioDiesel production. A reaction mechanism has been proposed based on investigations on the chlorination of different alcohols.
- Giomi, Donatella,Malavolti, Marino,Piccolo, Oreste,Salvini, Antonella,Brandi, Alberto
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p. 46319 - 46326
(2015/02/19)
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- Improved postsynthesis strategy to Sn-beta zeolites as lewis acid catalysts for the ring-opening hydration of epoxides
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Nanocrystalline Sn-Beta zeolites have been successfully prepared via an improved two-step postsynthesis strategy, which consists of creating vacant T sites with associated silanol groups by dealumination of parent H-Beta and subsequent dry impregnation of the resulting Si-Beta with organometallic dimethyltin dichloride. Characterization results from UV-vis, XPS, Raman, and 119Sn solid-state MAS NMR reveal that most Sn species have been successfully incorporated into the framework of Beta zeolite through the postsynthesis process and exist as isolated tetrahedral Sn(IV) in open arrangement. The creation of strong Lewis acid sites upon Sn incorporation is confirmed by FTIR spectroscopy with pyridine adsorption. The Sn-Beta Lewis acid catalysts are applied in the ring-opening hydration of epoxides to the corresponding 1,2-diols under near ambient and solvent-free conditions, and remarkable activity can be obtained. The impacts of Lewis acidity, preparation parameters, and reaction conditions on the catalytic performance of Sn-Beta zeolites are discussed in detail.
- Tang, Bo,Dai, Weili,Wu, Guangjun,Guan, Naijia,Li, Landong,Hunger, Michael
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p. 2801 - 2810
(2014/08/18)
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- Continuous dehydrochlorination of 1,3-dichloropropan-2-ol to epichlorohydrin: Process parameters and by-products formation
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The influence of pre-reactor and reactor temperatures on the conversion of 1,3-dichloropropan-2-ol and the selectivity of its transformation to epichlorohydrin in continuous dehydrochlorination for two modes of the reaction product collection was studied. The dehydrochlorination process and mechanism of diglycidyl ether formation are described.
- Krzy?anowska, Anna,Milchert, Eugeniusz
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p. 1218 - 1224
(2013/07/27)
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- METHOD FOR PREPARING CHLOROHYDRINS AND METHOD FOR PREPARING EPICHLOROHYDRIN USING CHLOROHYDRINS PREPARED THEREBY
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A method of preparing chlorohydrins and a method of preparing epichlorohydrin by using chlorohydrins prepared using the method are provided. The method of preparing chlorohydrins by reacting polyhydroxy aliphatic hydrocarbon with a chlorination agent in the presence of a catalyst includes at least one combination of a series of unit operations including a first reaction step, a water removal step, and a second reaction step, in that respective order, and after mixing at least a portion of a reaction mixture discharged from at least one reaction steps from among the plurality of reaction steps with an additional chlorination agent, recirculating the resulting mixture to the reaction step from which the reaction mixture was discharged. The method of preparing epichlorohydrin includes a step of reacting chlorohydrins prepared using the method of preparing chlorohydrins, with an alkaline agent.
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Paragraph 0105-0106
(2013/04/13)
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- METHOD FOR PREPARING CHLOROHYDRINS AND METHOD FOR PREPARING EPICHLOROHYDRIN USING CHLOROHYDRINS PREPARED THEREBY
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A method of preparing chlorohydrins and a method of preparing epichlorohydrin by using chlorohydrins prepared using the method are provided. The method of preparing chlorohydrins by reacting polyhydroxy aliphatic hydrocarbon with a chlorination agent in the presence of a catalyst includes at least one combination of a series of unit operations including a first reaction step, a water removal step, and a second reaction step, in that respective order, wherein the method further includes purifying chlorohydrins from a reaction mixture discharged from a final reaction step of the plurality of reaction steps. The method of preparing epichlorohydrin includes reacting chlorohydrins prepared using the method of preparing chlorohydrins, with an alkaline agent.
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Paragraph 0105-0106
(2013/04/24)
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- METHOD FOR PREPARING CHLOROHYDRINS COMPOSITION AND METHOD FOR PREPARING EPICHLOROHYDRIN USING CHLOROHYDRINS COMPOSITION PREPARED THEREBY
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Disclosed are a method for preparing chlorohydrins composition and a method for preparing epichlorohydrin using chlorohydrins prepared thereby. The disclosed method for preparing chlorohydrins composition reacts polyhydroxy aliphatic hydrocarbon with a chlorination agent in the presence of a catalyst, comprises at least one combination of a series of unit operations including a first reaction step, a water removal step, and a second reaction step in the respective order, and additionally comprises a step for reacting the chlorohydrins composition derived from a plurality of reaction mixtures discharged from the plurality of reaction steps with an alkaline chemical, and removing the catalyst included in the chlorohydrins composition in the form of an alkali metal salt. The disclosed method for preparing epichlorohydrin includes a step for contacting the chlorohydrins composition, which was prepared using the method for preparing chlorohydrins composition, with an alkaline chemical.
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Paragraph 0103-0104
(2013/05/08)
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- METHOD FOR PREPARING CHLOROHYDRINS COMPOSITION AND METHOD FOR PREPARING EPICHLOROHYDRIN USING CHLOROHYDRINS COMPOSITION PREPARED THEREBY
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Provided are a method of preparing a chlorohydrin composition and a method of preparing epichlorohydrin by using a chlorohydrin composition prepared by using the method. The method of preparing chlorohydrins in which polyhydroxy aliphatic hydrocarbon is reacted with a chlorination agent in the presence of a catalyst includes performing at least one combination of a series of unit operations comprising a first reaction step, a water removal step, and a second reaction step in this stated order, wherein the method further includes mixing a chlorohydrin concentrate obtained by purifying the reaction mixture discharged from the final reaction step from among the reaction steps and a water-rich layer discharged from the water-removal step and diluting the mixture with water. The method of preparing epichlorohydrin includes contacting the chlorohydrin composition prepared by using the method of preparing a chlorohydrin composition with an alkaline agent.
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Paragraph 0101-0102
(2013/05/08)
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- METHOD FOR PREPARING CHLOROHYDRINS AND METHOD FOR PREPARING EPICHLOROHYDRIN USING CHLOROHYDRINS PREPARED THEREBY
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A method of preparing chlorohydrins and a method of preparing epichlorohydrin using chlorohydrins prepared by using the same method are provided. The method is to prepare chlorohydrins by reacting polyhydroxy aliphatic hydrocarbon with a chlorination agent in the presence of a catalyst, and the method includes at least one combination of a series of unit operations including the following steps in the following stated order: a first reaction step; a water removal step; and a second reaction step, wherein the water removing step is performed by distillation operation based on a boiling point difference between constituents of a reaction mixture. The method of preparing epichlorohydrin includes reacting chlorohydrins prepared by using the method of preparing chlorohydrins with an alkaline agent.
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Paragraph 0101-0103
(2013/05/08)
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- METHOD FOR PREPARING CHLOROHYDRINS COMPOSITION AND METHOD FOR PREPARING EPICHLOROHYDRIN USING CHLOROHYDRINS COMPOSITION PREPARED THEREBY
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A method of preparing a chlorohydrin composition and a method of preparing epichlorohydrin by using a chlorohydrin composition prepared by using the method are provided. The method of preparing a chlorohydrin composition in which a polyhydroxy aliphatic hydrocarbon is reacted with a chlorination agent in the presence of a catalyst includes performing at least one combination of a series of unit operations comprising a first reaction step, a water removal step, and a second reaction step in this stated order, wherein the method further includes mixing a chlorohydrin concentrate obtained by purifying the reaction mixture discharged from the final reaction step from among the plurality of reaction steps and a water-rich layer discharged from the water-removal step. The method of preparing epichlorohydrin includes contacting the chlorohydrin composition prepared by using the method of preparing a chlorohydrin composition with an alkaline agent
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Paragraph 0099-0100
(2013/05/08)
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- METHOD FOR PREPARING CHLOROHYDRINS AND METHOD FOR PREPARING EPICHLOROHYDRIN USING CHLOROHYDRINS PREPARED THEREBY
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A method of preparing chlorohydrins and a method of preparing epichlorohydrin by using chlorohydrins prepared using the method are provided. The method of preparing chlorohydrins by reacting polyhydroxy aliphatic hydrocarbon with a chlorination agent in the presence of a catalyst includes at least one combination of a series of unit operations including a first reaction step, a water removal step, and a second reaction step, in that respective order, wherein the method further includes purifying chlorohydrins from a reaction mixture discharged from a final reaction step of the plurality of reaction steps. The method of preparing epichlorohydrin includes reacting chlorohydrins prepared using the method of preparing chlorohydrins, with an alkaline agent.
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Paragraph 0102-0103
(2013/05/22)
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- METHOD FOR PREPARING CHLOROHYDRINS AND METHOD FOR PREPARING EPICHLOROHYDRIN USING CHLOROHYDRINS PREPARED THEREBY
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A method of preparing chlorohydrins and a method of preparing epichlorohydrin using chlorohydrins prepared by using the same method are provided. The method is to prepare chlorohydrins by reacting polyhydroxy aliphatic hydrocarbon with a chlorination agent in the presence of a catalyst, and the method includes at least one combination of a series of unit operations including the following steps in the following stated order: a first reaction step; a water removal step; and a second reaction step, wherein the water removing step is performed by distillation operation based on a boiling point difference between constituents of a reaction mixture. The method of preparing epichlorohydrin includes reacting chlorohydrins prepared by using the method of preparing chlorohydrins with an alkaline agent.
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Paragraph 0101-0102
(2013/05/22)
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- METHOD FOR PREPARING CHLOROHYDRINS COMPOSITION AND METHOD FOR PREPARING EPICHLOROHYDRIN USING CHLOROHYDRINS COMPOSITION PREPARED THEREBY
-
A method of preparing a chlorohydrin composition and a method of preparing epichlorohydrin by using a chlorohydrin composition prepared by using the method are provided. The method of preparing a chlorohydrin composition in which a polyhydroxy aliphatic hydrocarbon is reacted with a chlorination agent in the presence of a catalyst includes performing at least one combination of a series of unit operations comprising a first reaction step, a water removal step, and a second reaction step in this stated order, wherein the method further includes mixing a chlorohydrin concentrate obtained by purifying the reaction mixture discharged from the final reaction step from among the plurality of reaction steps and a water-rich layer discharged from the water-removal step. The method of preparing epichlorohydrin includes contacting the chlorohydrin composition prepared by using the method of preparing a chlorohydrin composition with an alkaline agent
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Paragraph 0099-0100
(2013/05/22)
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- PROCESS FOR THE CHLORINATION OF A HYDROXYLATED ORGANIC COMPOUND
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Process for the chlorination of an organic compound comprising at least one aliphatic hydroxyl group, said process comprising the steps of actively adding to said organic compound (i) hydrogen chloride and (ii) a HCl desolubilizer or a precursor thereof, and heating the resulting mixture at a reaction temperature in the range 20°-160°C, wherein said chlorination is performed in the presence of a catalyst selected from the group consisting of (a) ketones, (b) aldehydes, (c) carboxylic acids with 1-8 carbon atoms, (d) organic compounds comprising a β-diketone moiety or a β-keto aldehyde moiety, and (e) organic polymers comprising at least one carbonyl group, having a vapour pressure at the reaction temperature of less than 1 mbar, a weight average molecular weight Mw of 500 g/mole or more, and are soluble in the reaction mixture at the reaction temperature, and wherein the HCl desolubilizer is an alkali metal chloride salt, an alkaline earth metal chloride salt, or an acid.
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Page/Page column 17; 18
(2013/03/26)
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- Hydration of epoxides on [CoIII(salen)] encapsulated in silica-based nanoreactors
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A confined workspace has its benefits in the case of a non-acid solid catalyst prepared by encapsulating [CoIII(salen)] in the nanocages of mesoporous silica. The catalytic activity and selectivity of [Co III(salen)] were increased significantly owing to the enhanced cooperative activation effect in the nanoreactors. Thus, ethylene oxide (EO) underwent hydration at a low 2:1 H2O/EO molar ratio to give ethylene glycol in up to 96 % yield. Copyright
- Li, Bo,Bai, Shiyang,Wang, Xuefeng,Zhong, Mingmei,Yang, Qihua,Li, Can
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supporting information
p. 11517 - 11521
(2013/01/15)
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- Catalytic activity of metal organic framework Cu3(BTC) 2 in the cycloaddition of CO2 to epichlorohydrin reaction
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We demonstrate the novel, catalytic activity of metal organic framework of Cu3(BTC)2 catalysts in the synthesis of chloropropene carbonate from CO2 and epichlorohydrin. The catalysts display moderate epoxide conversions, and moderate selectivities to chloropropene carbonate at 100 °C. No solvents or co-catalysts were required. It is suggested that Lewis acid copper (II) sites in the Cu3(BTC) 2 framework promoted the adsorption of carbon dioxide on the solid surface and its further conversion to the carbonate.
- MacIas, Eugenia E.,Ratnasamy, Paul,Carreon, Moises A.
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p. 215 - 218
(2013/01/15)
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- Covalent triazine frameworks as heterogeneous catalysts for the synthesis of cyclic and linear carbonates from carbon dioxide and epoxides
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The base catalytic properties of a series of triazine-based covalent organic frameworks were evaluated for the conversion of CO2 to organic carbonates. The high number of basic nitrogen sites of the as-synthesized frameworks efficiently catalyzed the formation of cyclic carbonates via the cycloaddition of CO2 to different starting epoxides. The structural and chemical tunability of the covalent triazine frameworks allowed the fine evaluation of key parameters influencing the observed catalytic activities. An increased surface area and presence of additional mesopores dramatically enhance the activity of the investigated catalytic materials. The chemical composition was also found to influence the reaction, as evidenced by an increased activity at lower reaction temperatures, when a more basic, pyridine-based, framework was used as catalyst. Finally, the activity in the two-step cycloaddition/transesterification catalysis of dimethyl carbonate was evaluated in a one-batch process. Copyright
- Roeser, Jerome,Kailasam, Kamalakannan,Thomas, Arne
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p. 1793 - 1799,7
(2012/12/11)
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- Covalent triazine frameworks as heterogeneous catalysts for the synthesis of cyclic and linear carbonates from carbon dioxide and epoxides
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The base catalytic properties of a series of triazine-based covalent organic frameworks were evaluated for the conversion of CO2 to organic carbonates. The high number of basic nitrogen sites of the as-synthesized frameworks efficiently catalyzed the formation of cyclic carbonates via the cycloaddition of CO2 to different starting epoxides. The structural and chemical tunability of the covalent triazine frameworks allowed the fine evaluation of key parameters influencing the observed catalytic activities. An increased surface area and presence of additional mesopores dramatically enhance the activity of the investigated catalytic materials. The chemical composition was also found to influence the reaction, as evidenced by an increased activity at lower reaction temperatures, when a more basic, pyridine-based, framework was used as catalyst. Finally, the activity in the two-step cycloaddition/transesterification catalysis of dimethyl carbonate was evaluated in a one-batch process. Copyright
- Roeser, Jér?me,Kailasam, Kamalakannan,Thomas, Arne
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p. 1793 - 1799
(2013/01/14)
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