- 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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Paragraph 0073-0075; 0092-0096; 0152-0153; 0168; 0196
(2020/11/14)
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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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- 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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- Regioselective Formal [3+2] Cycloadditions of Urea Substrates with Activated and Unactivated Olefins for Intermolecular Olefin Aminooxygenation
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A new class of intermolecular olefin aminooxygenation reaction is described. This reaction utilizes the classic halonium intermediate as a regio- and stereochemical template to accomplish the selective oxyamination of both activated and unactivated alkenes. Notably, urea chemical feedstock can be directly introduced as the N and O source and a simple iodide salt can be utilized as the catalyst. This formal [3+2] cycloaddition process provides a highly modular entry to a range of useful heterocyclic products with excellent selectivity and functional-group tolerance.
- Wu, Fan,Alom, Nur-E,Ariyarathna, Jeewani P.,Na?, Johannes,Li, Wei
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supporting information
p. 11676 - 11680
(2019/07/31)
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- Ruthenium-Catalyzed Urea Synthesis by N-H Activation of Amines
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Activation of the N-H bond of amines by a ruthenium pincer complex operating via amine-amide metal-ligand cooperation is demonstrated. Catalytic formyl C-H activation of N,N-dimethylformamide (DMF) is observed in situ, which resulted in the formation of CO and dimethylamine. The scope of this new mode of bond activation is extended to the synthesis of urea derivatives from amines using DMF as a carbon monoxide (CO) surrogate. This catalytic protocol allows the synthesis of simple and functionalized urea derivatives with liberation of hydrogen, devoid of any stoichiometric activating reagents, and avoids the direct use of fatal CO. The catalytic carbonylation occurred at low temperature to provide the formamide; a formamide intermediate was isolated. The consecutive addition of different amines provided unsymmetrical urea compounds. The reactions are proposed to proceed via N-H activation of amines followed by CO insertion from DMF and with liberation of dihydrogen.
- Krishnakumar, Varadhan,Chatterjee, Basujit,Gunanathan, Chidambaram
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supporting information
p. 7278 - 7284
(2017/06/23)
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- Ionic liquids/ZnO nanoparticles as recyclable catalyst for polycarbonate depolymerization
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A useful protocol for waste bis-phenol A-polycarbonates (BPA-PC) chemical recycling is proposed based on a bifunctional acid/basic catalyst composed by nanostructured zinc oxide and tetrabutylammonium chloride (ZnO-NPs/NBu4Cl) in quality of Lewis acid and base, respectively. Retro-polymerization reaction proved to be of general application for several nucleophiles, including water, alcohols, amines, polyols, aminols and polyamines, leading to the complete recovery of BPA monomer and enabling the PC polymer to function as a green carbonylating agent (green phosgene alternative) for preparing carbonates, urethanes and ureas. A complete depolymerization can be obtained in seven hours at 100 °C and ZnO nanocatalyst can be recycled several times without sensible loss of activity. Remarkably, when polycarbonate is reacted with glycerol, it is possible to realize in a single process the conversion of two industrial wastes (BPA-PC and glycerol) into two valuable chemicals like BPA monomer and glycerol carbonate (the latter being a useful industrial solvent and fuel additive).
- Iannone, Francesco,Casiello, Michele,Monopoli, Antonio,Cotugno, Pietro,Sportelli, Maria Chiara,Picca, Rosaria Anna,Cioffi, Nicola,Dell'Anna, Maria M.,Nacci, Angelo
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p. 107 - 116
(2016/12/09)
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- Efficient Reversible Hydrogen Carrier System Based on Amine Reforming of Methanol
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A novel hydrogen storage system based on the hydrogen release from catalytic dehydrogenative coupling of methanol and 1,2-diamine is demonstrated. The products of this reaction, N-formamide and N,N′-diformamide, are hydrogenated back to the free amine and methanol by a simple hydrogen pressure swing. Thus, an efficient one-pot hydrogen carrier system has been developed. The H2 generating step can be termed as "amine reforming of methanol" in analogy to the traditional steam reforming. It acts as a clean source of hydrogen without concurrent production of CO2 (unlike steam reforming) or CO (by complete methanol dehydrogenation). Therefore, a carbon neutral cycle is essentially achieved where no carbon capture is necessary as the carbon is trapped in the form of formamide (or urea in the case of primary amine). In theory, a hydrogen storage capacity as high as 6.6 wt % is achievable. Dehydrogenative coupling and the subsequent amide hydrogenation proceed with good yields (90% and >95% respectively, with methanol and N,N′-dimethylethylenediamine as dehydrogenative coupling partners).
- Kothandaraman, Jotheeswari,Kar, Sayan,Sen, Raktim,Goeppert, Alain,Olah, George A.,Prakash, G. K. Surya
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supporting information
p. 2549 - 2552
(2017/03/01)
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- Ruthenium-Catalyzed Urea Synthesis Using Methanol as the C1 Source
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An unprecedented protocol for urea synthesis directly from methanol and amine was accomplished. The reaction is highly atom-economical, producing hydrogen as the sole byproduct. Commercially available ruthenium pincer complexes were used as catalysts. In addition, no additive, such as a base, oxidant, or hydrogen acceptor, was required. Furthermore, unsymmetrical urea derivatives were successfully obtained via a one-pot, two-step reaction.
- Kim, Seung Hyo,Hong, Soon Hyeok
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supporting information
p. 212 - 215
(2016/02/03)
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- Hydrogen bond organocatalysis of benzotriazole in transamidation of carboxamides with amines
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A new method of transamidation of carboxamides with amines catalyzed by benzotriazole has been developed.
- Nguyen, Thanh Binh,Ermolenko, Ludmila,Dau, Marie-Elise Tran Huu,Al-Mourabit, Ali
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p. 403 - 416
(2014/01/17)
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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 0052
(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 24; 25
(2013/03/26)
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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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- 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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- Concomitant monoreduction and hydrogenation of unsaturated cyclic imides to lactams catalyzed by ruthenium compounds
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(Chemical Equation Presented) One for two: [Ru4H 6(p-cymene)4]Cl2 and [RuCl2(p- cymene)]2, [Ru], are efficient catalyst precursors for the selective transformation of cyclic imides into saturated lactams (see scheme). The catalytic systems operate with the same reagent (H2) to perform two transformations, namely, monoreduction of the carbonyl groups and hydrogenation of C=C bonds, with the release only of water, which is the solvent of the reaction.
- Aoun, Rimane,Renaud, Jean-Luc,Dixneuf, Pierre H.,Bruneau, Christian
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p. 2021 - 2023
(2007/10/03)
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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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- 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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- 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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- 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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- Synthesis and biological activity of mono- and bishydrazones of cyclic aminoguanidines
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The paper reports the synthesis of hydrazones of five- and six-membered cyclic aminoguanidines with some aliphatic, aromatic and arylaliphatic ketones and the results of the studies on their antibacterial, antifungal and antiyeast activity.
- Sidzhakova,Panajotova,Mardirossjan,Tabakova,Maneva,Marinova,Golovinsky
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p. 417 - 419
(2007/10/02)
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- Process for producing cyclic ureas
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A process for producing a cyclic urea is provided. The process comprises reacting a diamine expressed by the formula (II) wherein R represents hydrogen atom or a lower alkyl group and R' represent dimethylene group, a lower alkyl group-substituted dimethylene group, trimethylene group, a lower alkyl group-substituted trimethylene group, tetramethylene group, a lower alkyl group-substituted tetramethylene group, but a case where R represents hydrogen atom and R' represent dimethylene group, a case where R represents hydrogen atom and R' represents a lower alkyl group-substituted dimethylene group and a case where R represent methyl group and R' represents dimethylene group are excluded, with phosgene in the presence of a dehydrochlorinating agent. In the process, the diamine is first converted to its hydrochloride, followed by reacting the hydrochloride with phosgene in water solvent while maintaining a pH of the reaction liquid in the range of 5.0 to 8.0 by said dehydrochlorinating agent to obtain a cyclic urea expressed by the formula (I) STR1 wherein R and R' are each as defined above.
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- Ureas from N-Chloroamidines; An Aza-Analogous Hofmann Degradation
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N-Chlorination and subsequent treatment with alkali of suitably substituted benzamidines yields ureas with phenyl or alkyl migration.Under the same conditions, 2-iminopyrrolidine is converted into 2-oxohexahydropyrimidine with ring enlargement.
- Sonnenschein, Helmut,Schmitz, Ernst
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p. 443 - 444
(2007/10/02)
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- 2-Oxo-1-[[(substituted sulfonyl)amino]-carbonyl]azetidines
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Antibacterial activity is exhibited by 2-azetidinones having a 3-acylamino substituent and having an activating group in the 1-position of the formula STR1 wherein R4 is STR2 wherein A1 is a single bond, STR3 --NH-- or STR4 A2 is a single bond, --NH--, --CH2 --CH2 --NH-- or STR5 A3 is a single bond, --CH=CH--, --(CH2)t --, --NH--(CH2)p -- or STR6 wherein t is 1, 2, 3 or 4 and p is 0 or 1; and A4 is a single bond --CH2 --, --NH--CH2 --, or --N=CH--.
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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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- s-Triazolodiazacycloalkanes. I. Synthesis and Reactions of 3-Oxo-2,3,5,6,7,8-hexahydro-s-triazolo-pyrimidine
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3-Oxo-2,3,5,6,7,8-hexahydro-s-triazolopyrimidine (5) was synthesized and its reactivity towards acylating reagents was examined.The assignment of tautomeric structures based on n.m.r. spectral data is discussed.
- Krezel, Izabella
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p. 331 - 334
(2007/10/02)
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- CARBONYLATION OF AMINES AND DIAMINES CATALYZED BY NICKEL CARBONYL
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The carbonylation of amines and diamines was carried out using nickel carbonyl as the catalyst. reaction of butylamine, diethylamine, and diphenylamine with carbon monoxide all lead exclusively to the corresponding formamide derivative.Benzylamine reacts with carbon monoxide to yield urea and 1,2-diphenylethane.Diamines such as ethylenediamine, 1,2-diaminopropane, and 1,3-propylenediamine react to yield a cyclic condensation product, a cyclic uren, and a carbamic acid.
- Martin, Wilbur E.,Farona, Michael F.
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p. 393 - 397
(2007/10/02)
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- Mechanistic Studies in the Chemistry of Urea. Part 9. Reactions of 1,2-Diaminoethane and Related Compounds with Urea and N-Alkylated Ureas
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Reaction of urea with 1,2-diaminoethane results in formation of imidazolidin-2-one (1).Isotopic labelling and a study of the reactions of N-alkylated 1,2-diaminoethane indicate that the reaction mechanism involves an isocyanate intermediate. 1,3-Diaminopropane gives a similar product.
- Butler, Anthony R.,Hussain, Ishtiaq
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p. 317 - 319
(2007/10/02)
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- Process for the preparation of cyclic ureas
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A novel process is disclosed for the preparation of cyclic ureas having the formula STR1 wherein A is a straight chain alkylene radical of 2 to 4 carbon atoms, inclusive, wherein said alkylene radical can be substituted by at least one member selected from the group consisting of halogen, lower alkyl, lower alkoxy, aryl, aryloxy, aralkyl, and cycloaklyl. An alkylene diamine having the formula NH2 ANH2, wherein A is defined as above, is reacted in a solvent with carbonyl sulfide to form the corresponding N-(ω-aminoalkyl)thiocarbamic acid (NH2 ANHCOSH) or zwitterion thereof. The thiocarbamic acid is then heated to form the cyclic urea. The cyclic ureas are useful as cross-linkers and extenders in polyurethane formulations, and those ureas having 4 carbons in the alkylene chain find particular utility in the production of bis cyclic ureas which serve as masked isocyanate compounds in one-component polyurethane elastomer formulations.
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