112-27-6Relevant articles and documents
Synthesis and hydrolysis behavior of side-chain functionalized norbornenes
Carlise, Joseph R.,Kriegel, Robert M.,Rees Jr., William S.,Weck, Marcus
, p. 5550 - 5560 (2005)
The stabilities of various functionalized norbornenes that are monomers for the ring-opening metathesis polymerization (ROMP) in aqueous solution were evaluated toward hydrolysis under a range of temperatures (37, 60, and 80 °C) and pH values (3-9). All monomers contain hydrolyzable linkages to pendant functional groups, and conclusions were drawn relating to how the chemical diversity of these pendant functional groups, in accordance with the pH and temperature variations, affect hydrolysis of the aforementioned linkages. The hydrolysis was monitored by reverse phase HPLC analysis, and/or NMR spectroscopy. As expected, monomers containing ester linkages were fairly labile at higher pH values, while acetal-based linkers were cleaved at lower pH values. β-Amino ester groups experienced a significant increase in hydrolysis rate, while carboxylic acid-containing monomers did not follow any clear trend. Saccharide-containing monomers exhibited unique behaviors for various pH values and temperature ranges.
Substituted diether diols by ring-opening of carbocyclic and stannylene acetals
Martinez-Bernhardt, Rolando,Castro, Peter P.,Godjoian, Gayane,Gutierrez, Carlos G.
, p. 8919 - 8932 (1998)
Reduction of malonaldehyde bis(ethylene and propylene acetals) with borane or monochloroborane produces diether diols 1 and 2 in high yield. Similar reduction of glyoxal his(ethylene acetals) has only limited utility for the preparation of tetrasubstituted triethylene glycols 3. Organotin chemistry is complementary: stannylene acetals prepared from disubstituted vicinal diols can be alkylated with half an equivalent of 1,2-dibromoethane to produce tetrasubstituted triethylene glycols 3, or with two equivalents of 2-chloroethanol to produce disubstituted triethylene glycols 4.
Nanotitania catalyzes the chemoselective hydration and alkoxylation of epoxides
Ballesteros–Soberanas, Jordi,Leyva–Pérez, Antonio,Martínez–Castelló, Aarón,Oliver–Meseguer, Judit,Tejeda–Serrano, María
, (2021/10/12)
Glycols and ethoxy– and propoxy–alcohols are fundamental chemicals in industry, with annual productions of millions of tons, still manufactured in many cases with corrosive and unrecoverable catalysts such as KOH, amines and BF3?OEt2. Here we show that commercially available, inexpensive, non–toxic, solid and recyclable nanotitania catalyzes the hydration and alkoxylation of epoxides, with water and primary and secondary alcohols but not with phenols, carboxylic acids and tertiary alcohols. In this way, the chemoselective synthesis of different glycols and 1,4–dioxanones, and the implementation of nanotitania for the production in–flow of glycols and alkoxylated alcohols, has been achieved. Mechanistic studies support the key role of vacancies in the nano–oxide catalyst.
CO2atmosphere enables efficient catalytic hydration of ethylene oxide by ionic liquids/organic bases at low water/epoxide ratios
Ding, Tong,Gao, Guohua,Xia, Fei,Yuan, Huixia,Zha, Jinyin,Zhang, Dawei,Zhang, Jingshun
supporting information, p. 3386 - 3391 (2021/05/25)
The development of an efficient and low-cost strategy for the production of monoethylene glycol (MEG) through hydration of ethylene oxide (EO) at low H2O/EO molar ratios is an important industrial challenge. We have established that by using CO2as the reaction atmosphere, hydration of EO can be achieved at a low H2O/EO ratio of 1.5?:?1 along with high yields (88-94%) and selectivities (91-97%) of MEG catalyzed by binary catalysts of ionic liquids and organic bases. The results are significantly better than those of experiments conducted under an atmosphere of N2. Isotope labeling experiments revealed that CO2had altered the reaction pathway and participated in the reaction, in which cycloaddition of EO with CO2occurred first followed by the hydrolysis of ethylene carbonate (EC) to generate MEG and recover CO2. The ionic liquids and organic bases synergistically catalyzed the one-pot two-step reaction. DFT calculations confirmed that this route is more kinetically favorable compared to the pathway of direct epoxide hydration.
Photocatalytic Degradation of Hexaethylene Glycol
Simangoye Ngobissi, Drocilia Ednah,Soufi, Jihène,Vanoye, Laurent,Richard, Dominique
, p. 1608 - 1614 (2017/08/29)
Abstract: Polyethylene glycol (PEG) photodegradation was studied in water under UV irradiation in the presence of catalytic amount of TiO2 using hexaethylene glycol as a model compound. Full conversion was achieved in 7 h with an average quantum yield around 1%. Formic acid was found to be the main intermediate and was slower to oxidize into CO2 (traces remains after 24 h). The other intermediates [lower PEG, oxidized PEG (formates, aldehydes and acids, acetic acid)] of the photodegradation have also been identified and quantified. A mechanism based on previous literature but also taking into account these new observations is proposed. Graphical Abstract: [Figure not available: see fulltext.].
Catalytic hydration process for production of ethylene glycol
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Paragraph 0035-0042, (2017/02/24)
The invention relates to a method for producing glycol by catalytic hydration, which solves the problems of high equipment investment and high energy consumption existed in the direct hydration production of glycol in prior art. The method comprises the following steps: a) a material flow 1 containing ethylene oxide and water is introduced in a catalytic hydration reaction unit R, a material flow 6 containing glycol can be obtained after the reaction; b) the material flow 6 is introduced in a feed preheater of an evaporation tower D3, and preheating is carried out to obtain a material flow 7; c) the material flow 7 is introduced in the center part of the evaporation tower, after being separated, a glycol aqueous solution 8 is obtained at the bottom of the evaporation tower, and a steam material flow 9 is obtained at the top of the tower; and d) the material flow 9 is divided into a material flow 10 and a material flow 11; the material flow 10 is introduced in the feed preheater of the evaporation tower D3; and the material flow 11 is introduced into a subsequent flow. The technical scheme can better solve the problems, and the method of the invention can be used in an industrial production for producing glycol by ethylene oxide catalytic hydration.
Bis-TEGylated poly(p-benzamide)s: Combining organosolubility with shape persistence
Schulze, Maren,Michen, Benjamin,Fink, Alke,Kilbinger, Andreas F. M.
, p. 5520 - 5530 (2013/08/23)
The synthesis of perfectly planar, bis-substituted aromatic polyamides is reported herein. With highly flexible triethylene glycol chains attached and conformational restriction through intramolecular, bifurcated hydrogen bonds these are among the most shape-persistent yet organo-soluble polymers to date. Starting from 4-nitrosalicylic acid, our group developed a route to phenyl-2,5-bis-TEGylated aminobenzoate, which could be polymerized by addition of lithium bis(trimethylsilyl)amide (LiHMDS). Since this technique has not been applied to step-growth polycondensations of polyaramides so far, the influence of two different solvents and an N-protective group was investigated. Therefore, substituted phenyl aminobenzoate derivatives carrying a free amine or an N-protective group have been polymerized. Additionally, the tendency for self-assembly of the readily soluble bis-TEGylated poly(p-benzamide) was observed by transmission electron microscopy (TEM) in the dried state. Dynamic light scattering (DLS) measurements of chloroform solutions did not indicate the formation of aggregates. Thus, intermolecular interactions, which other aromatic polyamides typically exhibit, are prevented. The access to bis-substituted, entirely rigid poly(p-benzamide)s via this new polycondensation method paves the way for exciting new structures in materials science and supramolecular chemistry.
Two-Stage, Gas Phase Process for the Manufacture of Alkylene Glycol
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Page/Page column 8, (2010/03/02)
A two-stage, gas phase process for manufacturing alkylene glycol (e.g., ethylene glycol) from an alkene (e.g., ethylene), oxygen and water, the process comprising the steps of: (A) Contacting under gas phase, oxidation conditions gaseous alkene and oxygen over a heterogeneous oxidation catalyst to produce a gaseous oxidation product comprising alkylene oxide, water and unreacted alkene;(B) Contacting under gas phase, hydrolysis conditions the gaseous oxidation product of (A) with added water over a heterogeneous hydrolysis catalyst to produce a gaseous alkylene glycol and unreacted alkene; and(C) Recycling the unreacted alkene of (B) to (A). The hydrolysis catalyst is selected from the group consisting of hydrotalcites, metal-loaded zeolites, phosphates, and metal-loaded ion-exchanged molecular sieves. The process improves over the conventional two-stage process by the elimination of steps and equipment to recover and refine alkylene oxide, the use of less water in the hydrolysis reaction, and the elimination of the entire evaporation train used in the recovery of alkylene glycol.
Process for the preparation of alkylene glycols
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Page/Page column 3-4, (2008/06/13)
Disclosed is a process for the preparation of alkylene glycols from the corresponding alkylene oxide, such as ethylene glycol from ethylene oxide, in the presence of water, a catalyst and, optionally, carbon dioxide. The catalyst contains an amphoteric compound, such as such as (ethylenedinitrilo) tetraacetic acid (EDTA). These befunctional compounds have both acid and base moieties. Preferably, a compound useful in the present invention forms a buffered solution in water, i.e., the acid and base moieties do not completely disassociate. The pH of the buffered solution should be 2-10, preferably 5-10, more preferably 4-9. A compound useful in the present invention is preferably organic with the base moiety and the acid moiety being separated by one to four carbon atoms.
Process for preparing alkylene glycols
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Page/Page column 2, (2008/06/13)
The invention relates to a process for preparing alkylene glycols by hydration of alkylene oxides in the presence of polyalkylene glycol dialkyl ethers of the formula [in-line-formulae]R1—O—[—(CH2CH2O)m(CH(CH3)CH2)—O]n—R2 [/in-line-formulae] in which m=0-100, n=0-100, where n+m is at least equal to 1, R1 is a C1- to C6-alkyl radical, R2 is a C1- to C6-alkyl radical, where R2 may be different from R1, with the proviso that for at least 50 mol % of the polyalkylene glycol dialkyl ether m+n is greater than or equal to 11.
