- Magnesium Ion Catalyzed P-N Bond Hydrolysis in Imidazolide-Activated Nucleotides. Relevance to Template-Directed Synthesis of Polynucleotides
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Magnesium, an ion necessary in enzymatic as well as in nonenzymatic template-directed polynucleotide-synthesizing reaction, has been found to catalyze the hydroxide ion attack on the P-N bond of selected 5'-monophosphate imidazolide derivatives of nucleotides, such as guanosine 5'-monophosphate 2-methylimidazolide (2-MeImpG), guanosine 5'-monophosphate imidazolide (ImpG), and adenosine 5'-monophosphate 2-methylimidazolide (2-MeImpA).Calcium ion behaves similarly, but quantitatively the effects are smaller.Pseudo-first-order rate constants of 2-MeImpG and ImpG hydrolysis as a function of Mg(2+) concentration have been obtained in the range 6 +/-, imidazolide moiety protonated) with OH(1-) rather than reaction of the anionic form (S(1-), imidazolide moiety deprotonated) with water.This conclusion is based on a study of the N-methylated substrates N-MeImpG and 1,2-diMeImpG, respectively, which were generated in situ by the equilibrium reaction of ImpG with N-methylimidazole and 2-MeImpG with 1,2-dimethylimidazole, respectively.In contrast, in the absence of Mg(2+) the reaction of S(1-) with water competes with the reaction of SH+/- with OH(1-).The present study bears on the mechanism of the Mg(2+)-catalyzed template-directed synthesis of oligo- and polynucleotides derived from 2-MeImpG and on thecompetition between oligonucleotide synthesis and hydrolysis of 2-MeImpG.
- Kanavarioti, Anastassia,Bernasconi, Claude F.,Doodokyan, Donald L.,Alberas, Diann J.
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- ELECTRON ADDITION TO HALOGEN DERIVATIVES OF IMIDAZOLES
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Exposure of various bromo- and iodo-imidazoles as dilute solutions in methanol or methyltetrahydrofuran at 77 K to 60Co γ-rays resulted in electron addition to yield major species which were not the expected ?* radical anions but ?* radical anions, the SOMO being primarily the C-hal ?* orbital with little delocalisation.
- Symons, Martyn C.R.,Bowman, Russell,Taylor, Peter F.
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- Alkylation method for nitrogen-hydrogen containing compounds and application thereof
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The invention discloses an alkylation method for nitrogen-hydrogen containing compounds and an application thereof, belonging to the technical field of synthesis of organic compounds. The invention provides a series of methods for a nitrogen alkylation reaction of N-H containing heterocyclic compounds (II) with N,N-dimethylformamide dialkyl acetal as an alkyl source under the condition of no participation of metals, and a product with a hydrogen atom on a nitrogen atom substituted by R1 is obtained. The method provided by the invention has the advantages of highly-efficient reaction, high yield, simple treatment after the reaction, simple and convenient operation, mild reaction conditions, no participation of the metals, high tolerance of functional groups of a reaction substrate, wide range and easy preparation of the substrate, high reaction efficiency after amplification of the reaction, and applicability to large-scale industrial production.
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Paragraph 0059; 0061
(2018/10/04)
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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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- Preparation method for 1,2-dimethylimidazole
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The invention discloses a preparation method for 1,2-dimethylimidazole. The method comprises the following steps: dissolving 2-methylimidazole in an organic solvent; carrying out heating, adding dimethyl carbonate and continuing a reaction; and after completion of the reaction, subjecting a reaction solution to pressure-reduced distillation and rectification so as to prepare 1,2-dimethylimidazole. Compared with the prior art, the invention has the beneficial effects that 2-methylimidazole is used as a raw material; 1,2-dimethylimidazole is synthesized in one step at high temperature; and the preparation method has the advantages of no waste water, high yield, simple operation, no by product, etc. and is easy for industrial large-scale production. According to the invention, dimethyl carbonate is used as a methylation reagent, so raw material cost is low and toxicity is small; and no catalyst is needed in the method, so considerable solid sylvite waste does not exist and post-treatment is simple.
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Paragraph 0020; 0021; 0023; 0024; 0025; 0026; 0027
(2017/03/08)
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- METHOD FOR PRODUCING 1,2-DISUBSTITUTED IMIDAZOLE
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PROBLEM TO BE SOLVED: To provide a 1,2-disubstituted imidazole production method which can suppress production of by-products and efficiently produce high-purity 1,2-disubstituted imidazole in a shorter reaction time than that of the conventional one. SOLUTION: A 1,2-disubstituted imidazole production method includes a first stage reaction step of reacting an aldehyde compound with ammonia and/or a primary amine, and a second stage reaction step of reacting a glyoxal compound and ammonia and/or a primary amine with reaction products in the first stage reaction step. The primary amine is reacted in at least one of the first stage reaction step and the second stage reaction step to produce 1,2-disubstituted imidazole in a flow manner. The reaction in at least one of the first stage reaction step and the second stage reaction step is performed in a pressurized state at a pressure of 1-50 MPa. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2017,JPOandINPIT
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Paragraph 0051-0052
(2017/06/14)
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- A 1,2-dimethyl imidazole of preparation method
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The invention discloses a preparation method of 1,2-dimethylimidazole. The method comprises the following steps: bisimidazole is prepared from aminoacetaldehyde diethyl acetal, succinamide and 2,4-dimethylbenzoic acid, and 1,2-dimethylimidazole is prepared from bisimidazole. Compared with the prior art, the method allows to the total conversion rate to reach 90% by continuously optimizing reaction conditions and the use amounts of other reagents, and has the advantages of high conversation rate, mild reaction conditions, recycling of a solvent and a catalyst used in the reaction process, low cost, and practicality.
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Paragraph 0029-0032
(2017/02/24)
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- Mechanistic Studies on the Palladium-Catalyzed Direct C-5 Arylation of Imidazoles: The Fundamental Role of the Azole as a Ligand for Palladium
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An in-depth mechanistic study on the palladium-catalyzed direct arylation of imidazoles at the C-5 position is presented. The interactions of triphenylphosphine (PPh3)-ligated aryl-Pd species with 1,2-dimethyl-1H-imidazole (dmim) have been studied in detail. In contrast with previous suggestions, phosphine-ligated organo-Pd species are not active and the reaction proceeds through imidazole-ligated organo-Pd intermediates. The kinetics of the oxidative addition of aryl halides with dmim-ligated Pd(0) species have been characterized in a Pd(dba)2/dmim model system. A thorough study of the equilibria involving novel [ArPd(dmim)2X] complexes (X=I, OAc) and the unexpected cationic [ArPd(dmim)3]+ is also reported. The ability of these species to effect the C-H arylation of dmim at room temperature in the presence of acetate is also demonstrated.
- Perego, Luca Alessandro,Grimaud, Laurence,Bellina, Fabio
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p. 597 - 609
(2016/02/27)
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- METHOD OF PREPARING DIALKYLCARBONATES
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The present invention relates to a process of preparing dialkylcarbonates, and particularly to an improved process of preparing dialkylcarbonates, which comprises performing a reaction between an alcohol compound and a chloroformate derivative in the presence of an imidazole compound, thereby enabling to prepare dialkylcarbonates with high yield in a mild condition without using toxic raw materials and to easily separate impurities.
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Page/Page column 11
(2008/06/13)
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- METHOD OF PREPARING FLUORINATED ALKOXYTRIALKYLSILANES
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The present invention relates to a process for preparing alkoxytrialkylsilane, and in particular to a process, wherein an imidazole compound is added as a HCl scavenger and a reaction promoter, thereby enhancing the yield of fluorinated alkoxytrialkylsilanes and reducing corrosion problem.
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Page/Page column 11-12
(2008/06/13)
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- Metal ion binding monomer and polymer
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The present invention relates to bis-imidazolyl compounds of the formula: STR1 and polymers having the above-identified bis-imidazolyl compounds as a polymerizable unit. The present invention further relates to a method for scavenging trace quantities of metal ions from various effluents sources using the polymers of the instant invention. The instant invention also is directed to the use of the above-identified polymers as corrosion inhibiting agents and as a film for use in gel electrophoresis.
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- Photochemistry of Phenyl-Substituted 1-Methylpyrazoles
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Direct irradiation of 1-methyl-4-phenylpyrazole (2) in methanol results in regiospecific phototransposition to 1-methyl-4-phenylimidazole (4) and in photocleavage to (E)/(Z)-3-(N-methylamino)-2-phenylpropenenitrile (5) and (E)/(Z)-2-(N-methylaimno)-1-phenylethenyl isocyanide (6). Deuterium labeling confirms that the phototransposition occurs via the P4 permutation pathway. Separate experiments show that 5 and 6 undergo (Z) → (E) isomerization and photocyclization to imidazole 4. Quantum yields for these reactions show that the sequence 2 → 6 → 4 is a major pathway for the P4 phototransposition of 2 → 4. Isocyanides were also detected as intermediates in the P4 phototransposition of a variety of other pyrazoles confirming the generality of this pathway in pyrazole photochemistry. Direct irradiation of 1-methyl-5-phenylpyrazole (3) resulted in the formation of 1-methyl-5-phenylimidazole (7), 1-methyl-2-phenylimidazole (8), and 1-methyl-4-phenylimidazole (4). Deuterium labeling revealed that these products were formed by P4, P6, and P7 permutation pathways, respectively. (E)/(Z)-3-(N-methylamino)-3-phenylpropenenitrile (9) and (E)/(Z)-2-(N-methylamino)-2-phenylethenyl isocyanide (10) photocleavage products were also formed in this reaction. Irradiation of 3 in furan solvent did not result in phototransposition but led to the formation of endo and exo adducts formed by Diels-Alder reaction of furan with 4-phenyl-5-methyl-1,5-diazabicyclo[2.1.0]pent-2-ene. This constitutes the first direct evidence for the formation of a 1,5-diazabicyclo[2.1.0]hex-2-ene from photolysis of a pyrazole and is consistent with the electrocyclic ring closure - heteroatom migration mechanism suggested for the P6 and P7 phototranspositions.
- Pavlik, James W.,Kebede, Naod
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p. 8325 - 8334
(2007/10/03)
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- Regioselective N-Alkylation of Imidazoles with Alcohols over Zeolites
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Vapour-phase alkylation of 4(5)-methylimidazole with MeOH over Y-zeolites selectively gave 1,5-dimethylimidazole in high yield, while the alkylation over Beta-zeolite gave 1,4-dimethylimidazole predominantly.
- Ono, Yoshio,Izawa, Yuriko,Fu, Zi-hua
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- HETEROGENEOUS CATALYSTS IN THE ALKYLATION OF IMIDAZOLES
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The reaction of imidazoles with alcohols at 300-400 deg C was studied in the presence of heterogeneous γ-Al2O3 catalysts and Y zeolites.The major reaction was found to be N-alkylation.This reaction is accompanied by C-alkylation on γ-Al2O3, while the selectivity relative to N-alkylation is close to 100percent on zeolite catalysts.The greatest activity with 100percent selectivity was found for H zeolite.The alkylation of methanol and ethanol by 2-methylimidazole at 310-320 deg C gave 1,2-dimethylimidazole in ca. 100percent yield and 1-ethyl-2-methylimidazole in 90percent yield respectively.The reaction of methanol and imidazole gave 1-methylimidazole in 99percentyield.This catalyst displays high stability and capacity for oxidative regeneration.
- Gitis, K. M.,Neumoeva, G. E.,Isagulyants, G. V.
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p. 547 - 550
(2007/10/02)
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- CATALYTIC SYNTHESIS OF C-ALKYLIMIDAZOLES OVER PLATINUM-ALUMINA CATALYSTS
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The synthesis of C-alkylimidazoles from 1,2-diamines and carboxylic acids over bifunctional platinum-alumina catalysts has been studied.It has been shown that this method is effective for the synthesis of 2-alkyl and 2,4-dialkylimidazoles including imidazoles with long-chain alkyls.The effect of the reaction temperature, space velocity of the flow of the raw materials, and dilution by hydrogen on the yield of product has been examined for the example of the synthesis of 2-methylimidazole from ethylenediamine and acetic acid, and the stability of the catalyst in continuous reaction cycles with intermediate oxidative regeneration has been studied.The composition of the accompanying products has been established and a mechanism proposed for their formation.Keywords: bifunctional catalyst, platinum-alumina catalyst, alkylimidazoles, 2-methylimidazole.
- Gitis, K. M.,Neumoeva, G. E.,Raevskaya, N. I.,Arutyunyants, G. A.,Isagulyants, G. V.
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p. 728 - 734
(2007/10/02)
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- INVESTIGATIONS OF 2-SUBSTITUTED IMIDAZOLES. 2. SYNTHESIS AND ELECTROPHILIC SUBSTITUTION OF 1-METHYL-2-(THIENYL-2)IMIDAZOLE. A CONVENIENT METHOD OF METHYLATION OF 2-R-IMIDAZOLES
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We have synthesized 2-(thienyl-2)imidazole and its N-methyl derivative.The latter product was obtained by nitration, bromination, acylation, and formylation, occurring as a rule on the thiophene ring.A general method for methylating 2-R-imidazoles with methyl iodide KOH-dimethoxy ethane is proposed.
- Stoyanov, V. M.,El'chaninov, M. M.,Pozharskii, A. F.
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p. 1140 - 1144
(2007/10/02)
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- Imidazol-5-yl Radicals as Reactive Intermediates
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Imidazol-5-yl radicals have been generated as reactive intermediates in reduction reactions e.g. the reduction of 5-bromo-1,2-dimethylimidazole with Na/NH3/tBuOH and the reduction of 5-iodo- and 5-bromo-imidazole with Bu3SnH, to yield 1,2-dimethylimidazole.The imidazol-5-yl radical resulting from the Na/NH3/tBuOH and Bu3SnH reduction of 5-Bromo-1-(but-3-en-1-yl)-2-methylimidazole has been trapped by exo-radical cyclisation to yield the bicyclic imidazole (7).Attempted SRN1 substitution reactions between nucleophiles and 5-bromo- and 5-iodo-1,2-dimethylimidazole were unsuccessful.The radical anions of 5-nitroimidazoles were shown not to dissociate to nitrite anions and the corresponding imidazol-5-yl radicals, thereby disproving a putative explanation for the generation of nitrite anions in the antimicrobial mode of action of 5-nitroimidazoles.A mechanism has been proposed to explain the release of nitrite in the mode of action of nitroimidazoles. 13C NMR spectroscopy has been used to distinguish between 4- and 5-bromo- and -iodo-imidazoles.
- Bowman, W. Russell,Taylor, Peter F.
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p. 919 - 924
(2007/10/02)
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- Reactions with Dimethyl Carbonate, 2. - N-Methylation of Imidazole and Derivatives
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The use of dimethyl carbonate as methylating agent for imidazole derivatives is demonstrated by selected examples.The comparison of the toxicological values of dimethyl carbonate and dimethyl sulfate should inspire to replace the highly toxic dimethyl sulfate by dimethyl carbonate.
- Lissel, Manfred
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- Dimethylcarbonat als Methylierungsmittel unter phasen-transfer-katalytischen Bedingungen
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Dimethyl carbonate (as well as diethyl, diallyl, dibenzyl carbonate and ethane-1,2-diyl carbonate) in the presence of potassium carbonate and 18-crown-6 (or Aliqual 336) is a versatile, cheap, and safer reagent for the methylation of a variety of organic substrates.
- Lissel, Manfred,Schmidt, Stefan,Neumann, Beate
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p. 382 - 383
(2007/10/02)
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- Hydrolyses of 2-Trimethylsilyl N1-Heterocycles. Involvement of Zwitterions in the Hydrolysis of 2-(Trimethylsilyl)-N-methylimidazole, 2-(Trimethylsilyl)pyridine, and 2-((Trimethylsilyl)methyl)-N-methylimidazole
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The title N-containing aromatic heterocycles (1,2, and 4, respectively) with a trimethylsilyl substituent at the 2-position hydrolize relatively rapidly to form trimethylsilanol and the corresponding 2-H heterocycle.In the case of 2-((trimethylsilyl)methyl)-N-methylimidazole (4) the heterocyclic product is N,2-dimethyl imidazole. pH vs. log kobsd profiles establish that the reaction proceeds faster at high than low pH and that above the pKa of the heterocyclic base the reaction is independent of pH. 2-(Trimethylsilyl)-N-methylpyridinium iodide (6) and 2-(trimethylsilyl)- N,N'-dimethylimidazolium iodide (5) salts hydrolyze with a first-order dependence on -> above pH 6 with no evidence for a pH-independent region at high pH.F- accelerates the reactions of 1 and 2 markedly at low pH but has no effect at pH 12.5.The results indicate that the dominant mechanism for hydrolysis of the title compounds over most of the pH/rate profile involves nucleophilic attack of OH- on the trimethylsilyl unit of the N-protonated base, the leaving group being the zwitterion (ylide) of the heterocycle.The bimolecular constants for attack of OH- on protonated 1 and 2 are comparable to those observed for attack of OH- on 5 and 6, respectively.Compound 1 a below pH 5 attacked by H2O as is 4, but such is not observed for 2.Only compound 4 suffers nucleophilic attack of OH- on the deprotonated base.For 1 and 2 at low pH, F- successfully competes with the intrinsically more nucleophilic OH- because the latter's concentration is so low, but at high pH the reaction proceeds entirely via OH- attack.
- Brown, R. S.,Slebocka-Tilk, H.,Buschek, J. M.,Ulan, J. G.
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p. 5979 - 5984
(2007/10/02)
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- Sulfur dioxide - imidazole adducts
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The disclosed compounds are adducts of imidazole or derivatives thereof and sulfur dioxide. The adducts are apparently of the Lewis acid-Lewis base type, and are useful as latent curing agents for epoxide resins. The adducts are prepared by interacting the imidazole and sulfur dioxide under anhydrous conditions. Equimolar imidazole-SO2 adducts can serve as a source of sulfur dioxide at room temperature.
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