95-92-1Relevant articles and documents
Cyanide selective chemodosimeter in aqueous medium, on test strips and its application in real sample analysis
Ghosh, Tamal,Raina, Ashish,Singh, Yadvendra,Yadav, Komal Kumar
, (2020)
Abstract: In this paper, synthesis, characterization and detection of CN? by the compound (N′1E,N′2E)-N′1,N′2-bis((2-hydroxynaphthalen-1-yl)methylene)oxalohydrazide (1) have been reported. Compound 1 is synthesized by the reaction of oxalyldihydrazide and 2-hydroxy-1-naphthaldehyde and characterized by FTIR, 1H NMR and ESI-Mass spectroscopy. UV–Visible spectral band of 1 is observed to be broadened and shifted to longer wavelength upon addition of CN? ion selectively in H2O-DMSO (8:2 v/v) medium. Based on the UV–Visible spectral data, the detection limit of cyanide ion for 1 is found to be 30.2 μM. Colourless solution of 1 changes to yellow in the presence of cyanide ion selectively. The same colour change is also observed on Whatman filter paper test strip. Fluorescence intensity of 1 is quenched due to the nucleophilic addition reaction of cyanide with one of the two imine carbons. 1H NMR titration of 1 with CN? ion corroborates the reaction of the latter with one of the two imine carbons of the former, leading to the appearance of cyanomethyl proton signal at 6.15 ppm and consequently, its behaviour as chemodosimeter. The above mentioned chemodosimeter nature of 1 is also validated by ESI-Mass spectroscopy data. Compound 1 is capable for the detection of CN? in water for real samples with concomitant colour change. Graphic abstract: Compound 1 behaves as selective cyanide chemodosimeter with associated change in its colour (in solution and on Whatman filter paper test strip) and fluorescence. 1H NMR titration and ESI-Mass data confirm the nucleophilic addition reaction of cyanide with 1. Compound 1 can be used for the detection of CN? in water for real samples.[Figure not available: see fulltext.].
Highly active Pd-Fe/α-Al2O3 catalyst with the bayberry tannin as chelating promoter for CO oxidative coupling to diethyl oxalate
Xing, Wei-Chao,An, Ji-Min,Lv, Jing,Irshad, Faisal,Zhao, Yu-Jun,Wang, Sheng-Ping,Ma, Xin-Bin
, p. 796 - 800 (2021)
A novel Pd-Fe/α-Al2O3 catalyst was synthesized by incipient-wetness impregnation method with bayberry tannin as chelating promoter and commercial hollow column Raschig ring α-Al2O3 as support for the synthesis of diethyl oxalate from CO and ethyl nitrite. A variety of characterization techniques including N2 physical adsorption, optical microscopy, scanning electron microscopy and energy dispersive system (SEM-EDS), inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), were employed to explore the relationship between the physicochemical properties and activity of catalysts. It indicated that a large number of phenolic hydroxyl groups in bayberry tannin can efficiently anchor the active component Pd, reduce the particle size and make the active Pd as a multi-ring distribution on the commercial α-Al2O3 support, which were beneficial to improve the catalytic activity for the production of diethyl oxalate from CO and ethyl nitrite. 0.3 wt% Pd-Fe/α-Al2O3 showed excellent catalytic activity and selectivity in a continuous flow, fixed-bed reactor with the loading amount of 10 mL catalysts. Under the mild reaction conditions, the space-time yield of diethyl oxalate was 978 g L?1 h?1 and CO conversion was 44% with the selectivity to diethyl oxalate of 95.5%.
A nanostructured CeO2 promoted Pd/α-alumina diethyl oxalate catalyst with high activity and stability
Jin, Erlei,He, Leilei,Zhang, Yulong,Richard, Anthony R.,Fan, Maohong
, p. 48901 - 48904 (2014)
A Pd/α-Al2O3 nanocatalyst was synthesized and investigated as a catalyst for CO oxidative coupling to diethyl oxalate and CeO2 was used as a promoter. With the highest activity and stability found so far, great CO conversion and diethyl oxalate selectivity were achieved due to the addition of CeO2. This journal is
One-pot production of diethyl maleate via catalytic conversion of raw lignocellulosic biomass
Cai, Zhenping,Chen, Rujia,Zhang, Hao,Li, Fukun,Long, Jinxing,Jiang, Lilong,Li, Xuehui
supporting information, p. 10116 - 10122 (2021/12/24)
The conversion of lignocellulose into a value-added chemical with high selectivity is of great significance but is a big challenge due to the structural diversities of biomass components. Here, we have reported an efficient approach for the one-step conversion of raw lignocellulose into diethyl maleate by the polyoxometalate ionic liquid [BSmim]CuPW12O40 in ethanol under mild conditions. The results reveal that all of the fractions in biomass, i.e., cellulose, lignin and hemicellulose, were simultaneously converted into diethyl maleate (DEM), achieving a 329.6 mg g-1 yield and 70.3% selectivity from corn stalk. Importantly, the performance of the ionic liquid catalyst [BSmim]CuPW12O40 was nearly twice that of CuHPW12O40, which can be attributed to the lower incorporation of the Cu2+ site in [BSmim]CuPW12O40. Hence, this process opens a promising route for producing bio-based bulk chemicals from raw lignocellulose without any pretreatment.
PROCESS FOR THE SYNTHESIS OF ETHYLENE GLYCOL
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Page/Page column 49-51, (2021/10/11)
The invention relates to a process for the production of ethylene glycol from CO2, comprising the steps of : i) Reducing CO2 to CO; ii) Reacting the CO produced in step i) with an amine to form an oxamide or an oxamate or with an alcohol to form an oxalate; and iii) Reducing the oxamide, oxamate or oxalate formed in step ii) to form ethylene glycol, a process for the production of an oxamide, oxamate or oxalate and a process for the production of polyethylene terephthalate.
Method for continuously producing diethyl oxalate
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Paragraph 0077-0091, (2021/06/21)
The invention provides a method for continuously producing diethyl oxalate. The method comprises the following steps: A) adding dimethyl oxalate, alcohol and a catalyst into a first reaction kettle, carrying out ester exchange reaction, continuously and sequentially feeding reaction liquid into a second reaction kettle, a third reaction kettle and a fourth reaction kettle which are connected with the first reaction kettle in series, and continuously carrying out ester exchange reaction; and B) sequentially introducing the reaction liquid in the fourth reaction kettle into a dealcoholization tower, a byproduct removal tower and a product tower to obtain diethyl oxalate at the top of the product tower. The method has the advantages that: 1) four-kettle continuous reaction is adopted, so that the reaction rate and the conversion rate are improved; 2) the side reaction is less, the byproduct is single, the byproduct can be continuously reacted to obtain the product, the atom utilization rate is close to 100%, the product purity reaches 99.99%, and the purity of the co-produced methanol is 99% or above; and 3) environmental protection advantage: basically no three wastes are generated, the catalyst is recycled, and the method belongs to a clean production process and meets environmental protection requirements.
New series of γ-pyrone based podands: Synthesis, characterization and study of their application in acetate salts cation trapping for nucleophilic substitution reactions
Teimuri-Mofrad, Reza,Aghaiepour, Alireza,Rahimpour, Keshvar
, p. 121 - 132 (2019/04/17)
Dialkyl 4-oxo-4H-pyran-2,6-dicarboxylates are synthesized via esterification of chelidonic acid or via intramolecular cyclization of dialkyl-2,4,6-trioxoheptanedioates. Reaction of the dialkyl 4-oxo-4H-pyran-2,6-dicarboxylates with a variety of glycol monoalkyl ethers produces a series of new podands in good yields. To demonstrate the use of these podands in cation trapping, nucleophilic substitution reactions are carried out with various acetate salts. The results indicate that the cation diameter’s compatibility with binding site leads to the best yield of reaction.
Method for synthesizing symmetric oxalate by using dimethyl oxalate and alcohols in one step
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Paragraph 0033-0042, (2019/01/06)
The invention relates to a method for synthesizing symmetric oxalate, in particular to a method for synthesizing the symmetric oxalate by using dimethyl oxalate and alcohols in one step. The symmetricoxalate is synthesized by using the dimethyl oxalate and the high carbon alcohols such as ethanol, propanol, butanol and pentanol as reaction raw materials and by adopting a one-step synthesis method. A catalyst used in the method is a mesoporous-microporous composite multifunctional basic catalyst, and has the advantages that mesopores significantly improve the mass transfer efficiency, while micropores significantly enlarge the specific surface area of a carrier and improve the dispersion of an active center. 10% MgO-5% Al2O3-8% Fe2O3/Na-meso-Y is used as the catalyst, the raw material ethanol and the dimethyl oxalate are enabled to be subjected to reaction under the atmospheric pressure at the temperature of 100 DEG C under the condition that the space velocity is 2 h-1, wherein the molar ratio of the raw material ethanol to the dimethyl oxalate is equal to 20 to 1; the selectivity of the product diethyl oxalate is stabilized to be about 82%, and the steady state operation is performed for 1000h; the catalytic activity and the product selectivity are basically unchanged. The whole reaction path has the characteristics of being short in synthetic route, simple in process flow and high in raw material conversion rate and product selectivity, and enabling the catalyst to be stable and non-deactivated.
Preparation method of methylallyl alcohol
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Paragraph 0024-0025, (2018/06/04)
The invention discloses a preparation method of methylallyl alcohol. The method is characterized in that the methylallyl alcohol and a carboxylate compound are obtained by adopting methylallyl chloride and carboxylate as raw materials and alcohol as a solvent. The solvent creatively adopts the alcohol, not an alkali or other solvents, so reaction conditions are mild, and the irritation to the rawmaterials is low; and more importantly, the carboxylate also can be obtained, the content of ether and salt products is low, the yield of the target product is high, so the method in the invention hasadvantages over traditional technologies characterized by adoption of the alkali as a hydrolysis agent, a two-step reaction and high byproduct content.
Method for synthesizing diethyl oxalate through catalyzation of modified graphene
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Paragraph 0013-0022, (2017/05/19)
The invention relates to a method for synthesizing diethyl oxalate through catalyzation of modified graphene. Enriched hydroxylated graphene oxide is added into a diethyl oxalate synthesization reactor before reaction, since the enriched hydroxylated graphene oxide has excellent physical and chemical properties, oxalic acid molecules and ethyl alcohol molecules efficiently and thoroughly react on the surface of the graphene, and the yield of the diethyl oxalate is increased to 99% or above from 93.3%. The method is simple and practical, the enriched hydroxylated graphene oxide can be recycled, and the method is low in cost and suitable for mass production.
