- Synthesis of substituted ureas from urea and halohydrins
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Substituted ureas were prepared by reactions of 1,2-halohydrins with urea and were tested as antimicrobial additives to motor oils.
- Magerramov,Abdinbekova,Kurbanova,Zamanova,Allakhverdiev
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- Kinetics and mechanism for CO2 scrambling in a N-carboxyimidazolidone analogue for N1-carboxybiotin
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The N-carboxyimidazolidone anion, 2-, was prepared as an analogue for N1-carboxybiotin, and the kinetics of its CO2-dependent chemistry were studied in polar aprotic media. The objective was to assess the viability of unimolecular CO2 elimination from N1-carboxybiotin as a microscopic step in biotin-dependent carboxyl transfer enzymes. The anionic 2- was prepared as its lithium salt by first deprotonating 2-imidazolidone with phenyllithium, followed by direct reaction with carbon dioxide. This procedure also permitted isolation of the 13C enriched derivative 2-{13C} by reaction with 13 CO2. Proton and 13C NMR and isotope-dependent FTIR measurements confirmed that carboxylation had occurred at the nitrogen atom of 2-imidazolidone to give 2-. Time-dependent FTIR spectroscopy showed that Li2 undergoes carboxyl exchange with free carbon dioxide, with kinetics indicative of rate-limiting unimolecular dissociation of the N-CO2 bond. Under these conditions, the weak Lewis acid Mg2+ catalyses the exchange of 2- with free CO2, which appears to be related to the ability of the metal ion to coordinate to 2-. Reaction of Li2 with carboxylic acids in DMSO results in acid-dependent decarboxylation of 2- with a rate that is dependent on the concentration of the acid and its pKa. A common mechanistic framework is presented for both Lewis acid catalyzed carboxyl exchange and acid-dependent decarboxylation that involves initial interaction at the carbonyl oxygen and which has the effect of polarizing the nitrogen lone pair toward the imidazolidone ring rather than the carboxyl group. Lewis acid interaction with the carbonyl oxygen thus weakens the N-CO2- bond and functions as a trigger for dissociation of CO2. In the context of biotin-dependent enzymes, this suggests a means by which the kinetically stable N1-carboxybiotin cofactor intermediate might be triggered for dissociation of CO2.
- Lihs, Fiona J.,Caudle, M. Tyler
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- ALKALINE HYDROLYSIS OF N-NITROSO-2-IMIDAZOLIDONE
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The hydrolysis of N-nitroso-2-imidazolidone has been studied kinetically between pH 8.3 and 12.6.This nitroso compound has an acid-base equilibrium whose constant has been determined spectrophotometrically (pKa 11.45).Only the acid form is reactive.At pH - and is subject to general base catalysis.These results are interpreted in terms of a mechanism involving an initial steady-state hydrate whose decomposition by base leads to the final products.At pH > 10 reaction paths of orders one and two in OH- appear.The second-order term reflects general base catalysis superimposed on a first-order term in OH- (the bases dimethylamine, sarcosine, piperidine, and HPO42- have been used).The results are interpreted by an initial OH- attack on the carbonyl group of the nitroso compound to give an intermediate which in the rate-controlling step reacts with bases, among them water (which explains the first-order term with respect to OH-).The low value of the Broensted relation (β ca.O) and the fact that the intermediate possesses no proton yielding a low pKa value suggest that there is inverse classical general base catalysis.
- Castro, Albino,Leis, J. Ramon,Pena, M. Elena,Tato, Jose Vazquez
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- Ethylenethiourea S-Oxidation Products: Preparation, Degradation, and Reaction with Proteins
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Ethylenethiourea (ETU) is carcinogenic degradation product of major ethylene bis(dithiocarbamate) fungicides with biological activity attributed to poorly characterized oxidation products.The reaction of ETU with H2O2 was examined in aqueous medium at pH percent, 7, and 9 by 1H NMR spectroscopy giving five principal products: sequential formation of sulfenic, suflinic, and sulfonic acids as well as imidazoline and ethyleneurea.Maximum yields with 2 equiv of H2O2 at optimal pH were 10, 71, 5, 53, and 100percent, respectively.Oxidation proceeds mainly through the sulfinic acid to imidazoline in acidic medium and the S-oxide to ethyleneurea in basic medium. 1H NMR of urine from mice treated with ETU revealed ETU and imidazoline (no ethyleneurea or S-oxidation products).Albumin was radiolabeled in ca.17percent yield by a 10-fold excess of ETU/H2O2 oxidation products (primatily the sulfenic and sulfinic acids), and such protein modification aould be prevented by glutathione.Keywords: Ethylenethiourea; ethylenethiourea S-oxidation products; hydrogen peroxide; imidazoline; protein adducts; sulfenic acid
- James, Joyce P.,Quistad, Gary B.,Casida, John E.
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- CO2-Fixation on Aliphatic α,ω-Diamines to Form Cyclic Ureas, Catalyzed by Ceria Nanoparticles that were Obtained by Templating with Alginate
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Ceria nanoparticles (average particle size: 8nm) have been obtained by the calcination of alginate aerogel beads that were precipitated from aqueous solutions of (NH4)2Ce(NO3)6. These nanoparticles were considerably more active as a catalyst for CO2-insertion into aliphatic α,ω-diamines than the analogous commercial CeO2 with larger particle size (40nm). CeO2 that was obtained by templating with the natural alginate biopolymer afforded the cyclic urea of ethylenediamine in EtOH solvent at 160°C in 37% yield. This yield is remarkable for a process that involves CO2 as a feedstock. Other α,ω-diamines, such as diethylenetriamine, N,N′-dimethylethylenediamine, N-(2-aminoethyl)acetamide, and 1,4-diaminobutane, also formed their corresponding cyclic ureas in 4-36% yield. The catalyst lost activity upon reuse, thereby leading to severe deactivation that was only partially recovered by washing with aqueous acidic solutions.
- Primo, Ana,Aguado, Eric,Garcia, Hermenegildo
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- Structure and conformational analysis of a macrocyclic ligand: [24, 26-DIOXO-3,6,14,17-tetraazapentacyclo (21.0.11,19.1 3,6.18,12.114,17)Hexacosan-1(23),8(25),9,11,19, 21-hexaene]
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24,26-Dioxo-3,6,14,17-tetraazapentacyclo((21.0.11,19.1 3,6.18,12.114,17)hexacosan-1(23),8(25),9,11,19, 21-hexaene, C22H24N4O2 FW=376.45, monoclinic, P21/n,a = 11.144(2) A, b = 6.395(1) A, c = 13.562(3) A, β = 95.81(1)°, V= 961.5(3) A3, Z =2, Dcol = 1.300 Mg/m3, μ = 0.685 mm-1, F(000)=400, λ (CuKα) = 1.5418 A final R1 and wR2 are 0.0409 and 0.1547, respectively. The macro ligand consists of two phenyl rings and two five-membered rings forming the walls of the central cavity which has roughly a square cross-section. The orientation of the phenyl ring is antiperiplanar and approximately perpendicular to the diazacyclopentanone ring which adopts envelope conformation. The molecules are stabilized by C-H ... O and C-H ... π types of intermolecular interactions in addition to van der Waals forces.
- Sony, S.M. Malathy,Kuppayee,Ponnuswamy,Murali,Rajakumar
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- ENHANCED REACTIVITY OF 1-CARBOXY-2-ETHOXY-2-IMIDAZOLINE, A BIOTIN MODEL, IN DECARBOXYLATION
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Summary: 1-Carboxy-2-ethoxy-2-imidazoline (1) decarboxylates five times as fast as 1-carboxy-2-imidazolidinone (2) in an aqueous alkaline medium.
- Kondo, Hiroki,Miura, Katsuhito,Sunamoto, Junzo
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- SBA-15 Supported Dendritic ILs as a Green Catalysts for Synthesis of 2-Imidazolidinone from Ethylenediamine and Carbon Dioxide
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In this work, a simple and facile approach is conducted for preparing many new SBA-15 supported dendritic imidazolium ILs heterogeneous catalysts SBA-15/IL(1–3) having high ionic density from SBA-15. SBA-15/IL(3) as a green heterogeneous catalyst can be used for synthesis of 2-imidazolidinone from ethylenediamine and carbon dioxide and considering solvent-free condition. SBA-15/IL(3) showed to have the highest catalytic activity besides a positive dendritic influence on the yields of the synthesis of 2-imidazolidinone in the presence of CO2 is seen because of existing the high-density peripheral zwitterionic ionic liquid functional groups on the biobased SBA-15/IL(3) catalyst surfaces. Graphical Abstract: [Figure not available: see fulltext.]
- Liu, Jinghan,Ma, Jianjun,Miao, Penghua,Min, Qingwang,Qi, Meijuan,Shamsa, Farzaneh
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- Synthesis method of heterocyclic compound containing bis (trimethylsilyl)
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The method comprises the following steps: first adopting bis (trichloromethyl) carbonate, ethylenediamine, an aqueous sodium hydroxide solution, chloroform and a supported catalyst to obtain 2 - imidazolidinone. Or, ethylenediamine, ethanol, distilled water, a supported catalyst, carbon disulfide and hydrochloric acid are prepared to obtain ethylene thiourea. The trimethylchlorosilane is dissolved in an organic solvent, ammonia gas is introduced, and heated to reflux until no white precipitate is generated and filtered to obtain the filtrate. The raw material 2 - imidazolidinone or ethylidene thiourea is then dissolved to obtain the raw material solution, ammonium sulfate is added, and the filtrate is added dropwise, heated and refluxed 5 - 6h, cooled to room temperature, filtered, and the product is obtained. The molar ratio of the raw material to the trimethyl chlorosilane is 1: (2.1 - 2.5), the quality of ammonium sulfate is 1.5 - 2% of the raw material. The preparation method is simple and high in yield.
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Paragraph 0029; 0034-0035; 0038; 0043-0044; 0065; 0067; ...
(2021/09/29)
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- METHOD OF PREPARING UREA USING AMINE COMPOUND AND CARBON DIOXIDE
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Disclosed is a production method of urea using an amine compound and carbon dioxide. The production method of urea includes a step of producing urea by using the amine compound and a 2-pyrrolidone derivative as a solvent and reacting with the carbon dioxide, thereby producing high yield cyclic urea under mild reaction conditions and no catalyst conditions.
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Page/Page column 10-15
(2020/11/14)
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- Rational design of bifunctional catalyst from KF and ZnO combination on alumina for cyclic urea synthesis from CO2 and diamine
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This study is mainly focused on the design of stable, active and selective catalyst for direct synthesis of 2-imidazolidinone (cyclic urea) from ethylenediamine and CO2. Based on the rationale for the catalyst properties needed for this reaction, KF, ZnO and Al2O3 combination was selected to design the catalyst. ZnO/KF/Al2O3 catalyst was prepared by stepwise wet-impregnation followed by the removal of physisorbed KF from the surface. High product yield could be achieved by tuning acid-base sites by varying the composition and calcination temperature. The catalysts were characterized by various techniques like XRD, N2-sorption, NH3-TPD, CO2-TPD, TEM, XPS and FT-IR measurements. It is shown that acidic and basic properties of the solvent can influence the activity and product selectivity for this reaction. Under optimized condition; 180 °C, 10 bar and 10 wt.% catalyst in batch mode, 96.3 % conversion and 89.6 % selectivity towards the 2-imidazolidinone were achieved.
- John, Crowny,Kulal, Nagendra,Shanbhag, Ganapati V.
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- Highly synergistic effect of ionic liquids and Zn-based catalysts for synthesis of cyclic carbonates from urea and diols
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The development of stable and efficient catalysts is an attractive topic for green chemistry reactions under mild reaction conditions. In order to improve solvent-free synthesis of cyclic carbonates from urea and diols, a binary catalyst systems of Zn-based and different ionic liquids (ILs) were developed and examined in this study. The yield of ethylene carbonate (EC) could reach to 92.2% in the presence of C16mimCl/ZnCl2 catalyst. Through exploring the structure-activity relationships of cation and anion, it was confirmed that a synergistic effect of cation and anion of catalyst had important influences on urea alcoholysis. Additionally, the controlling step of EC synthesis reaction involving the elimination of an ammonia molecule from intermediates had been revealed by in situ FT-IR. This could afford a guided insight for synthesizing cyclic carbonates with high yield. Furthermore, a possible mechanism for the catalytic process was proposed based on DFT and the experimental results via FT-IR, 1H-NMR and 13C NMR analysis, which revealed that not only a probable synergistic effects of cation-anion matters, but also C(2)-H of ILs and Zn2+ played a key role in accelerating the reaction of urea alcoholysis. This catalytic mechanism study is to provide a preliminary basis to develop novel catalysts for cyclic carbonates from urea and diols through a green synthetic pathway.
- Cheng, Weiguo,Deng, Lili,Dong, Li,He, Hongyan,Li, Zengxi,Qian, Wei,Shi, Zijie,Su, Qian,Sun, Wenzhong
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- Efficient Non-Catalytic Carboxylation of Diamines to Cyclic Ureas Using 2-Pyrrolidone as a Solvent and a Promoter
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Carboxylation reactions of diamines were found to proceed rapidly and non-catalytically, producing corresponding cyclic ureas in excellent yields and selectivities when 2-pyrrolidone (2-PY) was used as a solvent. A similar promoting effect with 2-PY was also observed for the carboxylation of monoamines by carbon dioxide (CO2). Most notably, the carboxylation reactions of mono- and diamines conducted in 2-PY afforded 2–4 times higher yields of corresponding dialkyl ureas and cyclic ureas compared with those in N-methyl-2-pyrrolidone (NMP). Such a dramatic promoting effect using 2-PY is believed to be associated with the multiple hydrogen bonding interactions between 2-PY and the CO2-containing species of amines. Due to such favorable interactions, carboxylation reactions seem to be more facilitated in 2-PY than in NMP. (Figure presented.).
- Hwang, Junhyeok,Han, Donggu,Oh, Jin Joo,Cheong, Minserk,Koo, Hyun-Joo,Lee, Je Seung,Kim, Hoon Sik
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p. 297 - 306
(2018/11/27)
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- PROCESS FOR MANUFACTURING A CYCLIC UREA ADDUCT OF AN ETHYLENEAMINE COMPOUND
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The invention pertains to a process for manufacturing a cyclic urea adduct of an ethyleneamine compound, the ethyleneamine compound having a linear -NH-CH2-CH2-NH- group, the process comprising the steps of - in an absorption step contacting a liquid medium comprising an ethyleneamine compound having a linear -NH-CH2-CH2-NH- group with a CO2-containing gas stream at a pressure of 1 -20 bara, resulting in the formation of a liquid medium into which CO2 has been absorbed, - bringing the liquid medium to cyclic urea formation conditions, and in an urea formation step forming cyclic urea adduct of the ethyleneamine compound, urea formation conditions including a temperature of at least 120°C, wherein the total pressure at the end of the urea formation step is at most 20 bara, wherein the temperature in the absorption step is lower than the temperature in the urea formation step. It has been found that the process according to the invention makes it possible to obtain cyclic urea adducts in an efficient manner in the absence of metal-containing catalysts and to perform the process under relatively mild conditions, in particular relatively low pressure. More specifically, by separating the CO2 absorption step from the urea formation step, the CO2 absorption step can be carried out at relatively low temperatures and pressures. And because the CO2 is already present in the system at the beginning of the urea formation step, the pressure in the urea formation step does not need to be high.
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Page/Page column 23-25
(2019/02/25)
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- A Reversible Liquid Organic Hydrogen Carrier System Based on Methanol-Ethylenediamine and Ethylene Urea
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A novel liquid organic hydrogen carrier (LOHC) system, with a high theoretical hydrogen capacity, based on the unpresented hydrogenation of ethylene urea to ethylenediamine and methanol, and its reverse dehydrogenative coupling, was established. For the dehydrogenation only a small amount of solvent is required. This system is rechargeable, as the H2-rich compounds could be regenerated by hydrogenation of the resulting dehydrogenation mixture. Both directions for hydrogen loading and unloading were achieved using the same catalyst, under relatively mild conditions. Mechanistic studies reveal the likely pathway for H2-lean compounds formation.
- Xie, Yinjun,Hu, Peng,Ben-David, Yehoshoa,Milstein, David
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supporting information
p. 5105 - 5109
(2019/03/11)
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- Visible-Light-Mediated Liberation and In Situ Conversion of Fluorophosgene
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The first example for the photocatalytic generation of a highly electrophilic intermediate that is not based on radical reactivity is reported. The single-electron reduction of bench-stable and commercially available 4-(trifluoromethoxy)benzonitrile by an organic photosensitizer leads to its fragmentation into fluorophosgene and benzonitrile. The in situ generated fluorophosgene was used for the preparation of carbonates, carbamates, and urea derivatives in moderate to excellent yields via an intramolecular cyclization reaction. Transient spectroscopic investigations suggest the formation of a catalyst charge-transfer complex-dimer as the catalytic active species. Fluorophosgene as a highly reactive intermediate, was indirectly detected via its next downstream carbonyl fluoride intermediate by NMR. Furthermore, detailed NMR analyses provided a comprehensive reaction mechanism including a water dependent off-cycle equilibrium.
- Petzold, Daniel,Nitschke, Philipp,Brandl, Fabian,Scheidler, Veronica,Dick, Bernhard,Gschwind, Ruth M.,K?nig, Burkhard
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supporting information
p. 361 - 366
(2018/11/23)
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- N-VINYLIMIDAZOLIDONE COMPOUND, AND POLYMER THEREOF
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PROBLEM TO BE SOLVED: To provide an N-vinylimidazolidone compound polymer that is expected to be applied for a cell culture material, a temperature-responsive material and others. SOLUTION: The present invention provides a polymer polymerized with an N-vinylimidazolidone compound (1) as a monomer, or a copolymer comprising the monomer and a monomer of a different structure (R1 is H, C1-12 alkyl or acyl; R2 and R3 is H or methyl). SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0068-0070
(2017/01/02)
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- Preparing method of ethyleneurea and formaldehyde scavenger
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The embodiment of the invention discloses a formaldehyde scavenger. The formaldehyde scavenger is suitable for being subjected to spraying and soft-cloth painting to cover the surfaces of furniture, doors, windows and leather products, and can go deep into products, free formaldehyde can be effectively blocked and removed, formaldehyde in products is removed accordingly, and the body safety of users is improved. The formaldehyde scavenger is prepared from ethyleneurea, urea, a wetting agent, an assistant and water prepared in the first claim to the fifth claim in a mixed mode. The embodiment of the invention further provides a preparing method of the ethyleneurea. The preparing method includes the following steps that A, ethidene diamine, the urea, ethylene glycol and the water are added into a reactor in the molar ratio of (1.4-1.5):1:(0.5-0.8):(1.5-2), and the mixture is stirred to be even, is heated to be at the temperature of 120 DEG C to 250 DEG C, continues to be stirred for 2 hours to 4 hours and is cooled to be at the temperature of 0 DEG C; B, sediment is taken after filtering, washed with absolute ethyl alcohol, purified and dried, and the ethyleneurea is obtained.
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Paragraph 0063-0070; 0113; 0114; 0115; 0116; 0122-0128
(2017/04/08)
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- Joint preparation method for morpholine and imidazolidinone
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The invention discloses a joint preparation method for morpholine and imidazolidinone. The joint preparation method comprises the following steps: uniformly mixing 100 weight parts of diethanol amine, 29 to 58 weight parts of cyanuric chloride and 700 to 790 weight parts of water; reacting for 15 to 16 hours at the temperature of 85 to 95 DEG C; distilling under reduced pressure to remove water; drying distilled residues to obtain a white solid; performing pyrolysis on the white solid to constant weight in inert gas flow at the temperature of 258 to 270 DEG C; simultaneously, cooling and liquefying all pyrolysis gas which is exhausted from the inert gas flow, and introducing the pyrolysis gas into fractionating equipment in a centralized manner; fractionating to obtain morpholine distillate at 128 to 129 DEG C and imidazolidinone distillate at 258 to 265 DEG C; finally, purifying the two distillates and respectively obtaining purified products of the morpholine and the imidazolidinone. According to the joint preparation method for the morpholine and the imidazolidinone, the morpholine and the imidazolidinone can be prepared in a joint manner; the total yield of the morpholine and the imidazolidinone reaches 50.6 percent or above; moreover, a pyrolysis residue by-product with a flame retardant function can also be obtained synchronously, and the yield of the pyrolysis residue by-product is 7.8 to 9.4 percent.
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Paragraph 0017; 0018; 0019; 0120
(2017/01/19)
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- Copper(II)-catalysed oxidative carbonylation of aminols and amines in water: A direct access to oxazolidinones, ureas and carbamates
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Copper(II) chloride catalyses the oxidative carbonylation of aminols, amine and alcohols to give 2-oxazolidinones, ureas and carbamates. Reaction proceeds smoothly in water under homogeneous conditions (Ptot = 4 MPa; PO2 = 0.6 MPa, PCO), at 100°C in relatively short reaction times (4 h) and without using bases or any other additives. This methodology represents an economic and environmentally benign non-phosgene alternative for the preparation of these three important N-containing carbonyl compounds.
- Casiello, Michele,Iannone, Francesco,Cotugno, Pietro,Monopoli, Antonio,Cioffi, Nicola,Ciminale, Francesco,Trzeciak, Anna M.,Nacci, Angelo
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- PEPTIDOMIMETICS COMPRISING N-AMINO CYCLIC UREA RESIDUES AND USES THEREOF
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Novel peptidomimetics comprising N-amino cyclic urea residues are disclosed. Use of such peptidomimetics for modulating the activity of CD36 or IL-1 receptor in a cell, and for treating CD36- or IL-1-related disease, disorder or condition is also described
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(2014/02/16)
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- Highly efficient synthesis of cyclic ureas from CO2 and diamines by a pure CeO2 catalyst using a 2-propanol solvent
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Pure cerium oxide (CeO2) acts as an effective and reusable heterogeneous catalyst for direct synthesis of cyclic ureas from CO2 and diamines even at a low CO2 pressure of 0.3 MPa. 2-Propanol is the most preferable solvent to provide good selectivity. The system composed of a CeO2 catalyst and a 2-propanol solvent is applied to various diamines to provide the corresponding cyclic ureas in high yields (78-98%), including six-membered-ring ureas that are difficult to be synthesized from CO 2. Based on the kinetic studies on the effect of CO2 pressure and amine concentration and FTIR studies on adsorption of ethylenediamine and CO2 onto CeO2, the following mechanism for the synthesis of cyclic urea is proposed: (1) formation of carbamic acid and carbamate species on CeO2, (2) decomposition of carbamic acid to a free amino group and CO2, (3) nucleophilic attack of the amino group on the carbamate on CeO2 to produce the cyclic urea and (4) desorption of the product and regeneration of CeO2.
- Tamura, Masazumi,Noro, Kensuke,Honda, Masayoshi,Nakagawa, Yoshinao,Tomishige, Keiichi
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supporting information
p. 1567 - 1577
(2013/09/24)
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- Catalyst-free selective oxidation of alcohols to carbonyls using trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane as an efficient oxidant
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A simple and efficient method for the selective oxidation of alcohols to ketones using trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane at room temperature is developed. The reactions were smoothly proceeded under catalyst-free conditions to provide ketones in quantitative yields within short reaction times. Also, this method is compatible with many functional groups including aldehydes, olefins, halogens, amines and esters. Graphical Abstract: [Figure not available: see fulltext.]
- Azarifar, Davood,Najminejad, Zohreh,Khosravi, Kaveh
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p. 979 - 983
(2013/09/23)
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- Process for the Synthesis of Cyclic Alkylene Ureas
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The invention relates to a process for the synthesis of cyclic alkylene ureas comprising reacting a difunctional amine A having two primary amino groups, and an aliphatic organic carbonate component C selected from the group consisting of dialkyl carbonates CD and of alkylene carbonates CA, wherein the ratio of the amount of substance n(-NH2) of primary amino groups -NH2 in the difunctional amine A to the sum n(C) of the amount of substance n(CD) of carbonate groups of a dialkyl carbonate CD and the amount of substance n(CA) of carbonate groups in an alkylene carbonate CA, is at least more than 2, and to the product obtained by this process.
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Paragraph 0036-0043
(2013/03/26)
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- PROCESS FOR THE SYNTHESIS OF CYCLIC ALKYLENE UREAS
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The invention relates to a process for the synthesis of cyclic alkylene ureas comprising reacting in the presence of a basic catalyst, a difunctional amine A having two primary amino groups, and an aliphatic organic carbonate component C selected from the group consisting of dialkyl carbonates CD and of alkylene carbonates CA, wherein the ratio of the amount of substance Ji(-NH2) of primary amino groups -NH2 in the difunctional amine A to the sum M(C) of the amount of substance n(CD) of carbonate groups of a dialkyl carbonate CD and the amount of substance n(CA) of carbonate groups in an alkylene carbonate CA, is at least more than 2, and to the product obtained by this process.
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Page/Page column 17; 18
(2013/03/26)
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- Double molecular recognition with aminoorganoboron complexes: Selective alcoholysis of β-dicarbonyl derivatives
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Double duty: Aminoorganoboron (AOB) complexes recognize alcohol and β-dicarbonyl units, and thereby facilitate chemo- and site-selective alcoholysis of the latter (see scheme). The complex activates both reaction partners. This strategy enables C-C, C-N, and C-O bond cleavage in addition/elimination reactions under near neutral pH conditions and provides a new method for functional group conversions. Copyright
- Oishi, Shunsuke,Saito, Susumu
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supporting information; experimental part
p. 5395 - 5399
(2012/06/18)
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- Synthesis of urea derivatives from amines and CO2 in the absence of catalyst and solvent
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Urea derivatives are obtained in mild to good yield from the reactions of primary aliphatic amines with CO2 in the absence of any catalysts, organic solvents or other additives. To optimize reaction conditions, experimental variables including temperature, pressure, the concentration of amine, reaction time etc. were studied. Satisfactory yields were obtained at the optimized conditions that are comparable to the presence of catalyst and solvent. The preliminary investigation of the reaction mechanism showed that alkyl ammonium alkyl carbamate was quickly formed as the intermediate, and then the final product was formed by the intramolecular dehydration.
- Wu, Chaoyong,Cheng, Haiyang,Liu, Ruixia,Wang, Qiang,Hao, Yufen,Yu, Yancun,Zhao, Fengyu
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experimental part
p. 1811 - 1816
(2011/02/22)
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- Synthesis of urea derivatives from CO2 and amines catalyzed by polyethylene glycol supported potassium hydroxide without dehydrating agents
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Polyethylene glycol supported potassium hydroxide (KOH/PEG1000) was developed as a recyclable catalyst for facile synthesis of urea derivatives from amines and CO2 without utilization of additional dehydrating agents. Primary aliphatic amines, secondary aliphatic amines, and diamines can be converted into the corresponding urea derivatives in moderate yields. Furthermore, the catalyst can be recovered after a simple separation procedure, and reused over 5 times with retention of high activity. Georg Thieme Verlag Stuttgart.
- Kong, De-Lin,He, Liang-Nian,Wang, Jin-Quan
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supporting information; experimental part
p. 1276 - 1280
(2010/06/20)
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- Discovery, structure-activity relationships, pharmacokinetics, and efficacy of glucokinase activator (2 R)-3-cyclopentyl-2-(4-methanesulfonylphenyl)-N- thiazol-2-yl-propionamide (RO0281675)
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Glucokinase (GK) is a glucose sensor that couples glucose metabolism to insulin release. The important role of GK in maintaining glucose homeostasis is illustrated in patients with GK mutations. In this publication, identification of the hit molecule 1 and its SAR development, which led to the discovery of potent allosteric GK activators 9a and 21a, is described. Compound 21a (RO0281675) was used to validate the clinical relevance of targeting GK to treat type 2 diabetes.
- Haynes, Nancy-Ellen,Corbett, Wendy L.,Bizzarro, Fred T.,Guertin, Kevin R.,Hilliard, Darryl W.,Holland, George W.,Kester, Robert F.,Mahaney, Paige E.,Qi, Lida,Spence, Cheryl L.,Tengi, John,Dvorozniak, Mark T.,Railkar, Aruna,Matschinsky, Franz M.,Grippo, Joseph F.,Grimsby, Joseph,Sarabu, Ramakanth
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supporting information; experimental part
p. 3618 - 3625
(2010/07/05)
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- Method for Making Carbamates, Ureas and Isocyanates
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The present invention provides methods of forming carbamates, ureas, and isocyanates. In certain embodiments these methods include the step of reacting an amine with an ester-substituted diaryl carbonate to form an activated carbamate which can be further derivitized to form non-activated carbamate or a urea. The urea or carbamate can be subjected to a pyrolysis reaction to form isocyanate.
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Page/Page column 10
(2010/05/13)
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- Stereoselective synthesis of trifluoromethyl-substituted 1,2-diamines by aza-Michael reaction with trans-3,3,3-trifluoro-1-nitropropene
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Aza-Michael addition of optically pure 4-phenyl-2-oxazolidinone to 3,3,3-trifluoro-1-nitropropene proceeds smoothly at low temperature with a high yield. Diastereoselectivity of the addition depends on the base used and lithiated species proved to be highly efficient affording 92% de. Optically pure 1,2-diamino-3,3,3-trifluoropropane is prepared in 58% yield from the aza-Michael addition product through a three-step procedure.
- Turconi, Jo?l,Lebeau, Luc,Paris, Jean-Marc,Mioskowski, Charles
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p. 8109 - 8114
(2008/02/08)
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- Method for the synthesis of amides and related products from esters or ester-like compounds
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A versatile, eco-friendly, and efficient method for the convenient conversion of esters and ester-like compounds into amides, peptides, carbamates, ureas, oxamides, oxamates, hydrazides, oxazolidinones, pyrazolones, oxazolidinediones, barbituric acids, and other molecules containing one or more OCN moieties in the presence of a diol or polyol is disclosed.
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Page/Page column 11
(2008/06/13)
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- Microwave-assisted preparation of cyclic ureas from diamines in the presence of ZnO
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A MW-assisted direct synthesis of cyclic ureas has been developed that proceeds expeditiously in the presence of ZnO thus shortening its reaction time; the process also eliminates the formation of byproducts when compared to the traditional methods involving conventional heating. A microwave-assisted facile method for the preparation of various ureas, cyclic ureas, and urethanes has been developed that affords nearly quantitative yield of products at 120°C (150 W), 71 kPa within 10 min using ZnO as a catalyst. The enhanced selectivity in this reaction is attributed to the deployment of ZnO whose absence results in poor yield and the generation of byproducts.
- Kim, Yong Jin,Varma, Rajender S.
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p. 7205 - 7208
(2007/10/03)
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- 2,'3-Amino-4-(n-hydroxyamino)-succinylamino-acetamides for use as cd23 formation inhibitors
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Compounds of formula (I): wherein X1 is alkyl, sulphonyl or carboxy: X2 is hydrogen or alkyl; R1 is arylmethyl or heterocyclylmethyl; R2 is alkyl, alkenyl, aryl, cycloalkyl or cycloalkenyl; and R3 is hydrogen, alkyl, alkenyl, alkynyl or aryl; are useful in the treatment of disorders mediated by s-CD23.
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- Synthesis of 2-oxazolidones by sulfur-assisted thiocarboxylation with carbon monoxide and oxidative cyclization with molecular oxygen under mild conditions
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Simple synthetic method on 2-oxazolidone derivatives was established. 2-Aminoethanols were easily subjected to the thiocarboxylation with carbon monoxide promoted by elemental sulfur, followed by the oxidative cyclization with molecular oxygen to give corresponding 2-oxazolidones in good yields under mild conditions (1 atm, rt). Furthermore, 2-imidazolidones and 2-thiazolidone were also prepared in good yields similarly.
- Mizuno, Takumi,Takahashi, Junko,Ogawa, Akiya
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p. 7805 - 7808
(2007/10/03)
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- Catalytic oxidative carbonylation of primary and secondary diamines to cyclic ureas. Optimization and substituent studies
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W(CO)6-catalyzed oxidative carbonylation of 1,3-propanediamine to the corresponding urea has been examined under a variety of conditions. Following optimization, the Thorpe-Ingold effect on ring closure was studied using 2,2-dialkyl-1,3-propanediamines. For the 2,2-dimethyl- and 2,2-dibutyl-1,3-propanediamines, the yields were increased significantly as compared to that of the unsubstituted case. The eight-membered cyclic urea 5-butyl-5-ethyl-1,3-diazepan-2-one (5f) was formed in 38% yield, while only trace amounts of the cyclic urea were produced from the parent 1,5-pentanediamine. In a study of secondary diamines, yields from the carbonylation of N,N′-dialkyl-2,2-dimethyl-1,3-propanediamines were lower than those obtained from the primary diamines. The main byproducts from secondary diamines were tetrahydropyrimidine derivatives formed from a competitive reaction of the substrate with the oxidant and base.
- Qian, Fang,McCusker, Jennifer E.,Zhang, Yue,Main, A. Denise,Chlebowski, Mary,Kokka, Michiyo,McElwee-White, Lisa
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p. 4086 - 4092
(2007/10/03)
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- Is there stereoelectronic control in hydrolysis of cyclic guanidinium ions?
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To assess stereoelectronic effects in the cleavage of tetrahedral intermediates, a series of five-, six-; and seven-membered cyclic guanidinium salts was synthesized. If stereoelectronic control by antiperiplanar lone pairs is operative, these are expected to hydrolyze with endocyclic C-N cleavage to acyclic ureas. However, hydrolysis in basic media produces mixtures of cyclic and acyclic products, as determined by 1H NMR analysis. The results show that in the six-membered ring antiperiplanar lone pairs provide a weak acceleration of the breakdown of the tetrahedral intermediate, but in five- and seven-membered rings there is no evidence for such acceleration, which instead can be provided by syn lone pairs.
- Perrin,Young
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p. 4446 - 4450
(2007/10/03)
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- A new photolabile linker for the photoactivation of carboxyl groups
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A new photolabile linker enabling nucleophilic cleavage of a carboxyl functionality upon irradiation with UV light (>290 nm) was developed. When the photocleavage is carried out in the presence of primary or secondary amines, amides are obtained in high yields and purifies, while the intramolecular version of this reaction leads to heterocycles via a cyclorelease mechanism.
- Nicolaou,Safina,Winssinger
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p. 900 - 903
(2007/10/03)
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- Di-tert-butyl dicarbonate and 4-(dimethylamino)pyridine revisited. Their reactions with amines and alcohols
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The reaction of BOC2O in the presence and absence of DMAP was examined with some amines, alcohols, diols, amino alcohols, and aminothiols. Often, unusual products were observed depending on the ratio of reagents, reaction time, polarity of solvent, pK(a) of alcohols, or type of amine (primary or secondary). In reactions of aliphatic alcohols with BOC2O/DMAP, we isolated for the first time carbonic-carbonic anhydride intermediates; this helps explain the formation of symmetrical carbonates in addition to the O-BOC products. In the case of secondary amines, we succeeded to isolate unstable carbamic-carbonic anhydride intermediates that in the presence of DMAP led to the final N-BOC product. The effect of N-methylimidazole in place of DMAP was also examined.
- Basel, Yochai,Hassner, Alfred
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p. 6368 - 6380
(2007/10/03)
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- Catalytic oxidative carbonylation of primary and secondary α,ω-diamines to cyclic ureas
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(matrix presented) Primary and secondary diamines can be catalytically carbonylated to cyclic ureas using W(CO)6 as the catalyst, I2 as the oxidant, and CO as the carbonyl source. Preparation of five-, six-, and seven-membered cyclic ureas from the diamines RNHCH2(CH2)nCH2NHR (n = 0-2; R = H, Me) and RNHCH2CH2NHR (R = Et, i-Pr, Bz) was achieved in moderate to good yields.
- McCusker, Jennifer E.,Grasso, Cara A.,Main, Andrea D.,McEiwee-White, Lisa
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p. 961 - 964
(2008/02/09)
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- Substituted cyclic ureas and derivatives thereof useful as retroviral protease inhibitors
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The present invention relates to substituted cyclic ureas and analogs thereof of formula (I): STR1 wherein, T is selected from: --N(R22)C(=Z)N(R23)--; --N(R22)C(=Z)C(=Z)N(R23)--; --N(R22)S(=Z')N(R23)--; --N(R22)S(=Z')2 N(R23)--; or --N(R22)P(=O)(R24a)N(R23)--; Z is O, S, NR24 ; and, Z' is O or NR24 ; or pharmaceutically acceptable salt forms or prodrugs thereof, which are useful as retroviral protease inhibitors, and to pharmaceutical compositions comprising such compounds and methods of using the same for treating viral infection.
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- Design and synthesis of peptides passing through the blood-brain barrier
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The blood-brain barrier (BBB) is a highly selective membranous barrier regulating the transport of substances in blood into the brain parenchyma. At present, delivery of biologically active peptides or peptide drugs into the brain is quite an important subject from the standpoint of chemotherapy for brain diseases H-MeTyr-Arg-MeArg-D-Leu-NH(CH2)8NH2 termed 001-C8 was first synthesized to elucidate the structural specificity of peptides for passing through the BBB. The Na-methylamino acid and D-amino acid residues were appropriately situated in this peptide to protect against the digestion by peptidase. Furthermore, a number of basic peptides were prepared as 001-C8 analogs for studying the relationship between structure and BBB permeability of peptides.
- Wakamiya, Tateaki,Kamata, Makoto,Kusumoto, Shoichi,Kobayashi, Hiroyuki,Sai, Yoshimichi,Tamai, Ikumi,Tsuji, Akira
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p. 699 - 709
(2007/10/03)
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- Solvent-accelerated decarboxylation of N-carboxy-2-imidazolidinone. Implications for stability of intermediates in biotin-dependent carboxylations
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The decarboxylation of N-carboxy-2-imidazolidinone has previously been established as a model for the transfer of carbon dioxide from N(1')-carboxybiotin. The present paper reports the pH-dependence of the reaction as well as the acceleration of the reaction in methanol and in acetonitrile. These results suggest that enzymic reactions of N(1')-carboxybiotin in a hydrophobic active site with decreased hydrogen bonding can be rapid if the energy of desolvation is compensated by the energy made available by association of the substrate and protein. In addition, a report on the decarboxylation of N-carboxy-2-imidazolidinone in organic solvents containing macrocycles (Kluger, R.; Tsao, B.J. Am. Chem. Soc. 1993, 115, 2089-90) must be reinterpreted on the basis of the inherent instability of the substrate under the reaction conditions.
- Rahil, Jubrail,You, Shaochun,Kluger, Ronald
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p. 12495 - 12498
(2007/10/03)
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- Facile desulfurization of cyclic thioureas by hydrogen peroxide in acetic acid.
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A simple, mild and synthetically useful method for the desulfurization of cyclic thioureas and related compounds, existing as thiol-thione tautomeric mixtures, by hydrogen peroxide in acetic acid is proposed. The effect of substituting different solvents for the acetic acid was investigated.
- Grivas,Ronne
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p. 225 - 229
(2007/10/02)
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- OXIDATION OF 2-MERCAPTOBENZOHETERAZOLES BY DIMETHYLDIOXIRANE. A NEW METHOD FOR A SYNTHESIS OF C-2 SUBSTITUTED BENZIMIDAZOLE, BENZOXAZOLE, AND BENZOTHIAZOLE DERIVATIVES
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New and efficient reactions in which 2-mercaptobenzoheterazoles are selectively converted by dimethyldioxirane, under mild experimental conditions, to several C-2 substituted benzoimidazole, benzoxazole, and benzothiazole derivatives are reported.
- Frachey, Giuseppe,Crestini, Claudia,Bernini, Roberta,Saladino, Raffaele,Mincione, Enrico
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p. 2621 - 2630
(2007/10/02)
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- Chiral auxiliaries and their use in the synthesis of chiral molecules
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Chiral imidazolidones and imidazolidinethiones having the general formula: STR1 where (a) Z is either oxygen or sulphur (b) the R groups are independently selected from hydrogen or R2 CO where R2 is C1 to C10 alkyl, C2 to C10 alkenyl or benzyl and (c) the two R1 groups are either (1) identical groups selected from C1 to C10 alkyl, phenyl or C1 to C6 alkyl or alkoxy substituted phenyl or (2) such that together they form an alkylene group of formula --(CH2)n -- where n=3 to 8. Most preferred are those compounds where both R groups are R2 CO and there is a C2 axis of symmetry running along the CZ double bond. Compounds of formula (I) where at least one R group is R2 CO are efficient chiral auxiliaries for a range of asymmetric electrophilic substitution reactions when used in homochiral form. As such they are important tools for synthesising a range of chiral pharmaceuticals, agrochemicals and the like.
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- Aryl substituted nitrogen heterocyclic antidepressants
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Antidepressant agents having the formula STR1 wherein R1 is a polycycloalkyl group; R2 is methyl or ethyl, X is O; and Y comprises a 5-membered heterocyclic ring having one or two nitrogens.
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- Carbonylation of Amines by Carbon Dioxide in the Presence of an Organoantimony Catalyst
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1,3-Dialkylureas (RNHCONHR; where R = Bu, i-Bu, s-Bu, t-Bu, allyl, Ph) and tetramethylurea were successfully prepared at 80 deg C under an initial CO2 pressure of 4.9 MPa, from the corresponding amines and carbon dioxide with catalysis by triphenylstibine oxide and assistance from tetraphosphorus decasulfide (Ph3SbO/P4S10).Monitoring of the reaction by 13C NMR revealed that the successive thiolation of carbamic acid to an intermediate antimony carbamate species and aminolysis of the carbamothioic acid thus formed constitute the reaction course.Cyclic ureas can also be synthesized by similar carbonylations of diamines (RNHCH2CH2NHR'; where R, R' = H, H; Me, H; Ph, H; HOCH2CH2, H; HOCHMeCH2, H; Me, Me).Furthermore, the Ph3SbO/P4S10 catalyst system enabled the preparation of trisubstituted ureas such as 1-butyl-3,3-diethylurea by a selective cocarbonylation of butylamine and diethylamine.
- Nomura, Ryoki,Hasegawa, Yasuhiro,Ishimoto, Mikio,Toyosaki, Takayuki,Matsuda, Haruo
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p. 7339 - 7342
(2007/10/02)
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- PHASE TRANSFER CATALYTIC PREPARATION OF THE DIPOLAR APROTIC SOLVENTS DMI AND DMPU
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The title compounds are prepared by methylation of the respective cyclic ureas Me2SO4/catalyst/powdered NaOH (for DMI) or K2CO3 (for DMPU).Improved procedures are communicated for the preparation of 2-imidazolidine and trimethylene urea.
- Dehmlow, Eckehard V.,Rao, Y. Ramachandra
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p. 487 - 494
(2007/10/02)
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