- Optimizing Multivariate Metal-Organic Frameworks for Efficient C2H2/CO2Separation
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Adsorptive separation of acetylene (C2H2) from carbon dioxide (CO2) promises a practical way to produce high-purity C2H2 required for industrial applications. However, challenges exist in the pore environment engineering of porous materials to recognize two molecules due to their similar molecular sizes and physical properties. Herein, we report a strategy to optimize pore environments of multivariate metal-organic frameworks (MOFs) for efficient C2H2/CO2 separation by tuning metal components, functionalized linkers, and terminal ligands. The optimized material UPC-200(Al)-F-BIM, constructed from Al3+ clusters, fluorine-functionalized organic linkers, and benzimidazole terminal ligands, demonstrated the highest separation efficiency (C2H2/CO2 uptake ratio of 2.6) and highest C2H2 productivity among UPC-200 systems. Experimental and computational studies revealed the contribution of small pore size and polar functional groups on the C2H2/CO2 selectivity and indicated the practical C2H2/CO2 separation of UPC-200(Al)-F-BIM.
- Fan, Weidong,Yuan, Shuai,Wang, Wenjing,Feng, Liang,Liu, Xiuping,Zhang, Xiurong,Wang, Xia,Kang, Zixi,Dai, Fangna,Yuan, Daqiang,Sun, Daofeng,Zhou, Hong-Cai
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supporting information
p. 8728 - 8737
(2020/12/25)
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- METHOD FOR PRODUCING HETEROAROMATIC CARBOXYLIC ACID
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PROBLEM TO BE SOLVED: To provide a method for producing heteroaromatic carboxylic acids at good yields, when producing the heteroaromatic carboxylic acids by the oxidation of methyl-substituted heteroaromatic compounds. SOLUTION: A method for producing a heteroaromatic carboxylic acid includes oxidizing a methyl-substituted heteroaromatic compound, having one or more methyl groups on a heteroaromatic ring, with a basic compound and a permanganate. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0039; 0045; 0046
(2018/08/09)
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- A ONE POT PROCESS FOR SYNTHESIS OF OXAZOLINE AND IMIDAZOLE COMPOUNDS FROM GLYCEROL
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The present invention disclose a single step one pot process for synthesis of oxazoline and imidazole derivatives from glycerol using solid acid metal catalyst with improved yield.
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Paragraph 0064-0067
(2017/09/08)
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- Pd-catalyzed coupling reaction of fluorinated propargyl amidines with aryl iodides
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Catalyzed by ligand free Pd(OAc)2, 2,5-disubstituted imidazole was prepared in good yield by the reaction of fluorinated propargyl amidines with iodoarene. Mechanistic studies indicated that this transformation occurs through a nitropalladation-reductive elimination pathway. The Royal Society of Chemistry.
- Li, Shan,Yuan, Yafen,Li, Yajun,Li, Zhengke,Zhang, Lisi,Wu, Yongming
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supporting information
p. 41 - 43
(2013/02/22)
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- Synthesis of 4,5-substituted imidazoles by a fast condensation of 1,2-diketones and urotropine in heterogeneous medium
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Starting from 1,2-diketones and urotropine in the presence of ammonium acetate, a simple and efficient solventless microwave-assisted synthesis of 4,5-disubstituted imidazoles was accomplished. Georg Thieme Verlag Stuttgart.
- Bratulescu, George
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experimental part
p. 2319 - 2320
(2010/02/28)
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- Formation of Two 4-Imidazolylmethylphosphonium Salts and their Synthetic Studies Toward Histamine H3-Ligands
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A simple and convenient preparation of {[1H-imidazol-4(5)-yl]methyl} triphenylphosphonium chloride (5) is described. The phosphonium salt 5 could be applied to the synthesis of 1-[1H-imidazol-4(5)-yl]-5-arylpentan- or 6-arylhexan-3-ones 4a-d exhibiting histamine H3-antagonistic activities via a 1,3-diazafulvene intermediate 6 generated from 5. Further, two-methylene-enlongated homolog 3 of imifuramine was efficiently synthesized, starting from Wittig olefination of aldehyde 24 using [(1-tritylimidazol-4-yl) methyl]triphenylphosphonium chloride 7.
- Harusawa, Shinya,Kawamura, Makoto,Koyabu, Shuji,Hosokawa, Tomoko,Araki, Lisa,Sakamoto, Yasuhiko,Hashimoto, Takeshi,Yamamoto, Yumiko,Yamatodani, Atsushi,Kurihara, Takushi
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p. 2844 - 2850
(2007/10/03)
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- Color developing agent, processing composition and color image-forming method
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A method for forming a color image comprises the step of developing an image-wise exposed silver halide color photographic photosensitive material at the presence of a 6-aminotetrahydroquinoline color developing agent which is the following compound or its analoge. According to this method, the rapid process can be attained and an image of a low fog density can be obtained. STR1
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- Improved Procedure for Preparing 4-Methylimidazole from Glucose
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Both stages of synthesis of 4-methylimidazole from glucose are improved. Toxic hydrogen sulfide is eliminated from the process.
- Kozlov, E. S.,Vovk, M. V.
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p. 545 - 546
(2007/10/03)
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- Synthesis of 4-Methylimidazole from α-Ethoxyacrolein
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A method for preparation of 4-methylimidazole by reaction of α-ethoxyacrolein with formaldehyde and ammonia has been proposed.Two procedures for isolation of 4-methylimidazole have been compared: extraction with isobutyl alcohol and reprecipitation in the form of bis(4-methyl-1-imidazolyl)zinc.
- Mamashvili, T. N.,Keiko, N. A.,Voronkov, M. G.
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p. 390 - 391
(2007/10/03)
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- Novel synthesis of N-unsubstituted imidazoles using N-trimethylsilylimines
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Cycloaddition of N-trimethylsilylimines 3 with the lithiotosylmethylisocyanates 4 is described. This provides a novel synthesis of 4-substituted and 4,5-disubstituted imidazoles from easily accessible aldehydes or organolithium reagents, under mild conditions and in a one-pot operation.
- Shih
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p. 595 - 598
(2007/10/02)
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- Process for preparing 2-unsubstituted imidazoles
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A process for preparing 2-unsubstituted imidazoles which comprises reacting an α-hydroxycarbonyl compound with a formamide in such amounts as to make the molar ratio of said formamide to said hydroxycarbonyl compound not more than 2 at a reaction temperature of 100°-170° C. in an atmosphere of ammonia gas. According to this process, 2-unsubstituted imidazoles may be obtained in very high yields. In addition, because no great excess of formamide is used in carrying out the reaction, an effect of not requiring the recovery operation incident to decomposition of formamide is obtained as well. And by removing formic acid formed as a by-product by the reaction, a reactor and separation equipment such as a distillation column are not corroded, and imidazoles of a high purity can be obtained.
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- Methylimidazole-Catalyzed Ester Hydrolysis: Nonlinear Kinetics
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The rate constants for acyl transfer from some p-nitrophenyl esters (of trimethylacetate, -butyrate, and -acetate) and from phenyl acetate to imidazole and to the various monomethylimidazole derivatives were examined over a wide range of amine concentration (0.03-3 M).These are all effective nucleophilic catalysts for ester hydrolysis.At low amine concentrations (with limiting ester) the rate constants for imidazole-catalyzed and 1-methylimidazole-catalyzed hydrolysis are nearly identical (2-methylimidazole is ca. 3 times smaller and 4-methylimidazole is ca. 3 times larger with the p-nitrophenyl esters).At high concentrations, however, the reactivities of the methylimidazoles differ markedly from that of imidazole.The observed pseudo-first-order rate constants appear to be an essentially linear function of imidazole concentration (up to ca. 0.5 M imidazole) but show a nonlinear dependence on methylimidazole concentration.With increasing methylimidazole concentration the reaction varies from first order to zero order in catalyst concentration.Ester hydrolysis in thus inhibited at high methylimidazole concentrations relative to the reaction with imidazole.Various explanations for this phenomena are explored, and results are interpreted in terms of a possible noncovalent complexation between the methylimidazoles and the ester.
- Gagliano, Ronald A.,Knowlton, Robert C.,Byers, Larry D.
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p. 5247 - 5250
(2007/10/02)
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- Models for Strong Interactions in Proteins and Enzymes. 1. Enhanced Acidities of Principal Biological Hydrogen Donors
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The acid dissociation energies of several key biological hydrogen donors are found to fall into a narrow range, ΔHoacid=352-355 kcal/mol.The strong acidities of these donor groups enhance the hydrogen bond strengths involved in the protein α-helix, imidazole enzyme centers and DNA.Specifically, the peptide link is modeled by the dipeptide analogue CH3CO-Ala-OCH3.Its acidity is strengthened, i.e. ΔHoacid is decreased by 8 kcal/mol compared with other amides, due to electrostatic stabilization by the second carbonyl in the peptide -CON-CH(CH3)CO- grouping.The acidity of imidazole is also strengthened by 8 kcal/mol compared with that of the parent molecule, pyrrole, primarily due to resonance stabilization of the ion.Hydrogen donor NH2 groups of adenine and cytosine are modeled by 4-aminopyrimidine, and the acidity of this amine group is strengthened by ring aza substitution.An intrinsic acidity optimized for hydrogen bonding strength therefore emerges as a common property of the diverse hydrogen donors in the protein α-helix, enzymes and DNA.This property may therefore be in part responsible for the natural selection of these molecules as principal biological hydrogen donors.
- Meot-Ner (Mautner), Michael
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p. 3071 - 3075
(2007/10/02)
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- CONVENIENT SYNTHESIS OF 2-THIONAPHTHYLMETHYL ISOCYANIDE: A USEFUL REAGENT FOR METHYL ISOCYANIDE TRANSFER
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The crystalline 2-thionaphthylmethyl isocyanide (1), prepared from the novel N-(formamidomethyl)-N-benzyl morpholinium iodide (2), via transfer of elements of CH2NHCHO, is totally devoid of pervasive odour.The cyclo-addition of the conjugate base of (1) to nitriles followed by desulfurization, under very mild conditions, provides an attractive route to imidazoles.
- Ranganathan, S.,Singh, W. P.
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p. 1435 - 1436
(2007/10/02)
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- A NEW SYNTHESIS OF UNSUBSTITUTED, 4(5), AND 4,5-SUBSTITUTED 1H-IMIDAZOLES.
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Novel synthesis of the title compounds based on the reaction of N-(aminomethyl) benzamide with 1,2-dicarbonyl compounds is described.
- Khalaj, A.,Ghafari, M.
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p. 5019 - 5020
(2007/10/02)
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- HIGH-YIELDING SYNTHESES OF 4(5)-SUBSTITUTED IMIDAZOLES VIA ORGANOLITHIUM INTERMEDIATES. THE UTILITY OF SULPHONAMIDE N-PROTECTION AND SILICON-CONTAINING BLOCKING GROUPS
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N-protection of imidazole as its N,N-dimethyl-sulphonamido derivative, and blocking of the 2-position with the triethylsilyl group permits regioselective 5-metallation with sec-butyl-lithium.The resulting organolithium intermediates react with a range of electrophiles and the products are easily deprotected to give the 4(5)-substituted NH-free imidazoles in good to excellent yields.Isolation of the silicon-blocked intermediate is unnecessary and, indeed, is disadvantageous to final yields, making the procedure attractively economical of time.
- Carpenter, Andrew J.,Chadwick, Derek J.
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p. 2351 - 2358
(2007/10/02)
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- Synthesis of Imidazoles from Alkenes
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Alkenes are converted into imidazoles through their epoxides by a sequence involving ring-opening with readily available 2-tributylstannyltetrazoles (8), dehydration of the resulting alcohols (9) using methyltriphenoxyphosphonium iodide in a improved procedure to give 1-alkenyltetrazoles (12), which give imidazoles (17) on photolysis.
- Casey, Michael,Moody, Christopher J.,Rees, Charles W.
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p. 1933 - 1941
(2007/10/02)
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- Preparation of 4-methylimidazoles
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A process for the preparation of 4-methylimidazoles by reacting methylglyoxal with ammonia and an aldehyde in aqueous solution, wherein the reaction is carried out at a pH of above 7 and either the reactants are all brought into contact simultaneously or the aldehyde and the methylglyoxal are added simultaneously to the aqueous ammonia solution.
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- A New Synthesis of Imidazoles
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Alkenes are converted into imidazoles through their epoxides by treatment with 2-tri-n-butylstannyltetrazoles (2), followed by dehydration with methyltriphenoxyphosphonium iodide in an improved procedure, and photolysis of the resulting vinyltetrazoles (4).
- Casey, Michael,Moody, Christopher J.,Rees, Charles W.
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p. 714 - 715
(2007/10/02)
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