- Synthesis of unsymmetrical urea from aryl- or pyridyl carboxamides and aminopyridines using PhI(OAc)2via in situformation of aryl- or pyridyl isocyanates
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A tandem synthesis of unsymmetrical ureas (N-aryl-N′-pyridylurea andN,N′-bipyridylurea) from aryl- or pyridyl carboxamides and aminopyridinesviaHofmann rearrangement has been reported. In particular, benzamides, picolinamide, nicotinamide, and isonicotinamide generate reactive intermediate isocyanates,in situ, in the presence of PhI(OAc)2, which upon further reaction with aminopyridines form urea derivatives. As the formation of pyridylisocyanates from their corresponding carboxamidesviaHofmann rearrangement remained unexplored previously, attempts have been made to trap the isocyanates. While the three pyridylisocyanates were trapped as their corresponding carbamates, 3-pyridylisocyanate was isolated and characterized. Unlike closely related previous methods reported for urea synthesis, the current method avoids direct use of isocyanates or eliminates the use of toxic phosgene for thein situgeneration of isocyanates.
- Hunjan, Mandeep Kaur,Laha, Joydev K.,Singh, Neha
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p. 18815 - 18823
(2021/10/26)
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- Photocatalyzed synthesis of unsymmetrical ureas via the oxidative decarboxylation of oxamic acids with PANI-g-C3N4-TiO2 composite under visible light
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The synthesis of unsymmetrical ureas via the photocatalyzed oxidative decarboxylation of oxamic acids has been developed. The carbamoyl radicals were generated from oxamic acids in the presence of a hypervalent iodine reagent and the PANI(Polyaniline)-g-C3N4-TiO2 composite under visible light irradiation. The radicals were converted in situ into the corresponding isocyanates, which were then trapped by amines to afford the corresponding products in moderate to good yields. This protocol avoided the direct use of environmentally unfriendly isocyanates and a series of substrates were tolerated. Moreover, the photocatalyst could be readily recovered by simple filtration and be reused for several runs with only a slight decrease in the catalytic activity.
- Wang, Liang,Wang, Hao,Wang, Yaoyao,Shen, Minggui,Li, Shubai
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supporting information
(2020/04/28)
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- Metal-free synthesis of pyridin-2-yl ureas from 2-aminopyridinium salts
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An unprecedented base promoted domino approach has been developed for the synthesis of pyridin-2-yl urea derivatives via the reaction of 2-aminopyridinium salts and arylamines. The developed strategy tolerated a wide range of functional groups and afforded pyridin-2-yl ureas in moderate to good yields. The reaction was postulated to involve tandem cyclization, intermolecular nucleophilic addition, ring opening, and demethylation.
- Saroj,Patel, Om P.S.,Rangan, Krishnan,Kumar, Anil
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- Palladium-Catalyzed Synthesis of Symmetrical and Unsymmetrical Ureas Using Chromium Hexacarbonyl as a Convenient and Safe Alternative Carbonyl Source
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Pd-catalyzed synthesis of urea derivatives from aryl iodides and different aliphatic and aromatic amines using sodium azide and chromium hexacarbonyl is described. In this process, carbonylation of aryl iodides, Curtius rearrangement of aroyl azides, and nucleophilic addition of amines sequentially occur to afford the products in good to excellent yields. This protocol is operationally simple and displays a broad substrates scope.
- Mozaffari, Mozhdeh,Nowrouzi, Najmeh
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supporting information
p. 7541 - 7544
(2019/12/12)
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- (Thio)urea-catalyzed friedel-crafts reaction: Synthesis of bis(indolyl)-methanes
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Bis(indolyl)methane derivatives (BIMs) were synthesized in moderate to good yields by (thio)urea catalyzed electrophilic substitution of indole (2) with various aldehydes 1. Reactions were performed under conventional and microwave (MW) heating, either using 1,2-dichloroetane as solvent or without solvent. The procedure using microwave heating was also applied to the synthesis of the natural products vibrindole A (3n), arsindoline A (3i), arundine (3o) and tris(1H-indol-3-yl)methane (3j). Additionally, the synthesis of streptindole was carried out via intermediate 3g. This methodology is well suited for the synthesis of bis(indolyl)methanes: it offers good yields of products, low sensitivity to moisture and oxygen, high tolerance to different functional groups on the aldehydes such as al-kynes and trimethylsilane, and simplicity in operation
- Rivas-Loaiza, Juan A.,Reyes-Escobedo, Carlos E.,Lopez, Yliana,Rojas-Lima, Susana,García-Merinos, Juan Pablo,López-Ruiz, Heraclio
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p. 959 - 968
(2019/11/22)
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- Glucokinase Activators Based on N-Aryl-N′-Pyridin-2-Ylurea Derivatives
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A series of previously undescribed N-aryl-N′-pyridin-2-ylureas were prepared via the reaction of 2-aminopyridines with benzoyl azides and tested in vitro as activators of glucokinase. Statistically significant reductions of glucose levels as compared with
- Semenov,Tarasova,Khramov,Semenova,Inchina,Vakaeva
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p. 209 - 212
(2018/06/07)
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- Disubstituted urea compound synthesis method
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The invention relates to a synthesis method of disubstituted urea compounds. The synthesis method comprises the following steps: (1) in an air atmosphere, adding amide, arylamine, cuprous iodide and 1,10-phenanthroline to a solvent N-N-dimethylformamide according to a molar ratio of 1:(1.0-2.0):(0.1-0.2):(0.2-0.4) and stirring at 110-130 DEG C till the reaction raw materials disappear; (2) by the end of the reaction, adding excess saturated salt water in to the system, extracting the product with ethyl acetate, washing an organic phase with saturated salt water, drying, and removing the solvent out of the organic phase through a rotary evaporator to obtain a crude product; and (3) purifying the crude product through column chromatography on silica gel in the presence of a developing solvent to obtain a corresponding disubstituted urea compound, wherein the developing solvent is selected according to the thin layer chromatography condition and the polarity condition of the products. The synthesis method of disubstituted urea compounds has the advantages that the raw materials are simple and easily available; the catalyst is cheap, a conventional solvent is used, and air is used as an oxidizing agent; and the operation is simple, the yield is medium to excellent; therefore, the synthesis method has a good development prospect in industrial production.
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Paragraph 0029; 0030
(2017/07/21)
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- ORGANIC MOLECULES FOR TERAHERTZ TAGGING APPLICATIONS
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The present invention discloses substituted heterocyclic compounds and /or aromatic compounds containing amide and/or urea groups exhibiting resonance in the range of 0.1- 10 THz. The invention also discloses binary molecular complexes based on the substituted heterocyclic compounds and/or aromatic compounds containing amide and/or urea groups of the present invention. The compounds and binary molecular complexes of the present invention have varying molecular mass and hydrogen bond strengths demonstrating several resonances below 10 THz. The compounds and binary molecular complexes of the present invention are customizable for various applications, such as authentication of a product.
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Page/Page column 16
(2015/07/23)
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- Synthesis of unsymmetrical 2-pyridyl ureas via selenium-catalyzed oxidative carbonylation of 2-aminopyridine with aromatic amines
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A simple, one-pot, phosgene-free approach to a series of unsymmetrical 2-pyridyl ureas starting from 2-aminopyridine and various aromatic amines is reported for the first time. The procedure employs inexpensive selenium as the catalyst, and carbon monoxide (instead of phosgene) as the carbonyl reagent. The products are obtained in moderate to good yields via selenium-catalyzed oxidative cross-carbonylation of the substrate amines in the presence of oxygen. The selenium functions as a phase-transfer catalyst and can be recovered easily and reused without any significant degradation of its catalytic activity.
- Zhang, Xiaopeng,Li, Desheng,Ma, Xueji,Wang, Yan,Zhang, Guisheng
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p. 1357 - 1363
(2013/07/05)
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- Synthesis of polynuclear azoles linked through carbamate and urea bridges
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Polynuclear azoles linked through carbamate and urea fragments were synthesized by reactions of the corresponding azolecarboxylic acid azides with heterocyclic alcohols and amines. Pleiades Publishing, Ltd., 2012.
- Golobokova,Pokatilov,Proidakov,Kazantseva,Shevchenko,Vereshchagin,Kizhnyaev
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experimental part
p. 566 - 574
(2012/07/02)
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- Microwave assisted, ligand free, copper catalyzed reaction of aryl halides with phenyl urea
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The ligand free coupling reaction of phenyl urea with different functionalized aryl halides in the presence of air stable Cu2O and t-BuOK as a base gives symmetrical and unsymmetrical diarylureas in relatively high yields. This method is milder than the palladium catalyzed arylation and avoids the use of toxic phosphine ligand.
- Gavade, Sandip N.,Balaskar, Ravi S.,Mane, Madhav S.,Pabrekar, Pramod N.,Shingare, Murlidhar S.,Mane, Dhananjay V.
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experimental part
p. 292 - 295
(2012/01/05)
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- Microwave assisted, solvent- and ligand-free copper catalyzed N-arylation of phenylurea with aryl halides
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An inexpensive and efficient catalyst system has been developed for the N-arylation of phenylurea including a variety of aryl halides. This simple protocol uses Cu2O as the catalyst, microwave assisted, solvent- and ligand-free, K3PO4.H2O as the base.
- Gavade, Sandip,Shingare, Murlidhar,Mane, Dhananjay
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experimental part
p. 4167 - 4170
(2012/02/16)
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- An efficient method for the N-arylation of phenylurea via copper catalyzed amidation
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The coupling reaction of phenylurea with different functionalized aryl halides in the presence of air stable CuI, N,N-dimethylethylenediamine as a ligand, and K3PO4 as a base gives symmetrical and unsymmetrical diarylureas in relatively high yields. This method is milder than the palladium catalyzed arylation and avoids the use of toxic phosphine ligands.
- Gavade, Sandip N.,Balaskar, Ravi S.,Mane, Madhav S.,Pabrekar, Pramod N.,Shingare, Murlidhar S.,Mane, Dhananjay V.
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experimental part
p. 675 - 678
(2012/01/13)
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- Isocyanate diinsertion into the N-H bond of the 2-pyridylamino ligand of organolanthanides
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[Cp2LnNHPy]2 (Py = 2-pyridyl) (1a-e) react with phenyl isocyanate to form the N-H diinsertion products Cp2Ln [η2:η1-PyNCON(Ph)CONHPh](THF) (Ln = Yb (3a), Er (3b), Y (3c), Dy (3d), Gd (3e)). It has been proven that n Pr 2NH can abstract one PhNCO unit from 3c to form Cp2 Y[η3-OC(NHPh)NPy] (2c) and nPr2 NHCONHPh (4), representing a rare example of selective release of a functional group of ligands in organolanthanide chemistry. Hydrolysis of 2c gives the organic nitrogen-containing product PyNHCONHPh (5). Moreover, 3c can also be obtained by the reaction of 2c with PhNCO. These results demonstrate that the diinsertion of PhNCO into the N-H bond of coordinated amino ligands might proceed in a stepwise manner. All the compounds were characterized by elemental analysis and spectroscopic properties. The structures of compounds 3a-e and 4 are also determined through X-ray single-crystal diffraction analysis. The Royal Society of Chemistry 2010.
- Sun, Yan,Zhang, Zhengxing,Wang, Xu,Li, Xiaoqing,Weng, Linhong,Zhou, Xigeng
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experimental part
p. 221 - 226
(2010/03/03)
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- A general method for the synthesis of unsymmetrically substituted ureas via palladium-catalyzed amidation
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A general and practical method for the preparation of unsymmetrically substituted ureas has been developed utilizing palladium-catalyzed amidation. Both aryl bromides and chlorides, as well as heteroaryl chlorides, have been coupled to aryl, benzyl, and a
- Kotecki, Brian J.,Fernando, Dilinie P.,Haight, Anthony R.,Lukin, Kirill A.
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supporting information; experimental part
p. 947 - 950
(2009/08/07)
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- Synthesis of new unsymmetrical 4,5-dihydroxy-2-imidazolidinones. Dynamic NMR spectroscopic study of the prototropic tautomerism in 1-(2-benzimidazolyl)- 3-phenyl-4,5-dihydroxy-2-imidazolidinone
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The acid-catalyzed cyclocondensation in refluxing acetonitrile of aqueous glyoxal with N-heteroaryl-N′-phenylureas 4a-f (heteroaryl = 2-thiazolyl, 2-pyrimidinyl, 2-pyrazinyl, 2-pyridinyl, 3-pyridinyl and 2-benzimidazolyl) led to the formation of the corre
- Ghandi, Mehdi,Olyaei, Abolfazl,Salimi, Farshid
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p. 768 - 775
(2007/10/03)
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- Corrosion-protective properties of 1-phenacylmethyl-2- arylcarbamido(arylthiocarbamido)pyridinium bromides
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Inhibiting effect of 1-phenacylmethylpyridinium bromides containing urea or thiourea substituents in the pyridinium ring on steel and zinc corrosion in sulfuric acid solutions was studied.
- Yurchenko,Pogrebova,Pilipenko,Shubina
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p. 1969 - 1972
(2008/02/09)
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- Regioselective preparation of pyridin-2-yl ureas from 2-chloropyridines catalyzed by Pd(0)
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The palladium-catalyzed ureidation reaction of 2-chloropyridines can be regioselectively performed in good yield, with both aryl and aliphatic ureas, using xantphos as the ligand, Pd(OAc)2 as the source of palladium, NaOt-Bu/H2O or N
- Abad, Antonio,Agullo, Consuelo,Cunat, Ana Carmen,Vilanova, Cristina
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p. 915 - 924
(2007/10/03)
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- Substituent Effects on Pyrid-2-yl Ureas toward Intramolecular Hydrogen Bonding and Cytosine Complexation
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Equilibria between two conformational isomers of pyrid-2-yl ureas, the (E,Z) and (Z,Z) forms, have been studied in DMF-d7 at -70 °C. Most of them show a small preference for the (E,Z) form with an equilibrium constant Ki around 1-2. However, the Ki value for 1-methyl-2-(3-(pyrid-2-yl)ureido)pyridinium iodide (12) was found to be 14.2 ± 1.2. That is 1 order of magnitude larger than those of the others, which indicates that the positively charged 1-methylpyridinium-2-yl substituent would facilitate the (E,Z) form formation. Pyrid-2-yl ureas bind cytosine in DMF-d7 with binding constants KB ranging from 30 to 1700 M-1. Electron withdrawing substituents, such as the 4-O 2NC6H4- or 1-methylpyridinium-4-yl substituent, preferentially facilitate the intermolecular cytosine complexation with large binding constants.
- Chien, Chia-Hui,Leung, Man-Kit,Su, Jen-Kuan,Li, Gene-Hsiang,Liu, Yi-Hung,Wang, Yu
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p. 1866 - 1871
(2007/10/03)
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- Photocleavage of pyridyl-based aromatic polyureas
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The photophysical properties of a metal chelating pyridyl-based aromatic ureas and poly-(1,4-phenylene-2,6-pyridylurea) were investigated. In their solution state and upon exposure to 365 nm UV radiation, these low and high molecular weight compounds were found to cleave the urea linkage nearly quantitatively, generating the corresponding amine-terminated subunits and CO2. Through a series of model compounds along with nuclear magnetic resonance (NMR), UV/vis absorption, and fluorescence spectroscopy characterization, the photocleavage process was delinated as a function of UV dose, O2, and water. The presence of water was found crucial to this photocleavage process with O2 playing a role only in subsequent oxidation of resulting amine functionalities. The experimental results support a light-assisted hydrolysis of the urea bond as the most plausible photocleavage mechanism. The photocleavage of such pyridyl-based ureas can potentially find usages in light-assisted base generation and/or for releasing metal cations.
- Mwaura, Jeremiah,Yang, Baocheng,Li, Rongfu,Morton, Martha,Papadimitrakopoulos, Fotios
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p. 9775 - 9783
(2007/10/03)
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- Novel substituted 4-aminomethylpiperidines as potent and selective human β3-agonists. Part 1: Aryloxypropanolaminomethylpiperidines
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The synthesis and SAR of a series of human β3 adrenoreceptor agonists based on a template derived from a common pharmacophore coupled with 4-aminomethylpiperidine is described. Potent and selective agents were identified such as 26 that was in vitro active in CHO cells expressing human β3-AR (EC50=49 nM, IA=1.1), and in vivo active in a transgenic mouse model.
- Steffan, Robert J.,Ashwell, Mark A.,Solvibile, William R.,Matelan, Edward,Largis, Elwood,Han, Stella,Tillet, Jeffery,Mulvey, Ruth
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p. 2957 - 2961
(2007/10/03)
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- Structure-based generation of a new class of potent Cdk4 inhibitors: New de novo design strategy and library design
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As a first step in structure-based design of highly selective and potent Cdk4 inhibitors, we performed structure-based generation of a novel series of Cdk4 inhibitors. A Cdk4 homology model was constructed according to X-ray analysis of an activated form of Cdk2. Using this model, we applied a new de novo design strategy which combined the de novo design program LEGEND with our in-house structure selection supporting system SEEDS to generate new scaffold candidates. In this way, four classes of scaffold candidates including diarylurea were identified. By constructing diarylurea informer libraries based on the structural requirements of Cdk inhibitors in the ATP binding pocket of the Cdk4 model, we were able to identify a potent Cdk4 inhibitor N-(9-oxo-9H-fluoren-4-yl)-N′-pyridin-2-ylurea 15 (IC50 = 0.10 μM), together with preliminary SAR. We performed a docking study between 15 and the Cdk4 model and selected a reasonable binding mode which is consistent with the SAR. Further modification based on the proposed binding mode provided a more potent compound, N-[(9bR)-5-oxo2,3,5,9b-tetrahydro-1H-pyrrolo[2,1-a]isoindol-9-yl]-N′ -pyridin-2-ylurea 26a (IC50 = 0.042 μM), X-ray analysis of which was accomplished by the soaking method. The predicted binding mode of 15 in Cdk4 was validated by X-ray analysis of the Cdk2-26a complex.
- Honma,Hayashi,Aoyama,Hashimoto,Machida,Fukasawa,Iwama,Ikeura,Ikuta,Suzuki-Takahashi,Iwasawa,Hayama,Nishimura,Morishima
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p. 4615 - 4627
(2007/10/03)
-
- Synthesis and characterisation of platinum(II) ureylene complexes, and the X-ray structure of [Pt{PhNC(O)NAd}(COD)] (Ad = 1-adamantyl, COD = 1,5-cyclo-octadiene)
-
Reaction of [PtCl2(COD)] or cis-[PtCl2(PPh3)2] with a range of mono-and di-substituted ureas, together with urea itself, and an excess of silver(I) oxide gives ureylene complexes 3 and 4 containing the Pt-N-C(O)
- Dinger, Maarten B.,Henderson, William,Nicholson, Brian K.,Wilkins, Alistair L.
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p. 303 - 312
(2007/10/03)
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- SYNTHESIS AND CERTAIN REACTIONS OF HETEROCYCLIC AMIDES OF 1,3,4,2-OXADIAZAPHOSPHOLINE
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Heterocyclic 1,3,4,2-oxadiazaphospholine amides were synthesized and the influence of the amide residue on the reactivity of these compounds in reactions with sulfur, phenyl isocyanate, carbonyl compounds and Schiff bases was disclosed.
- Yusupov, M. M.,Razhabov, A.
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p. 979 - 983
(2007/10/02)
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- MOLECULAR CONFORMATION OF 1,3-PYRIDYLPHENYLUREAS BY 1H AND 13C NMR STUDY
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1H and 13C NMR spectra are reported for several 1,3-pyridylphenyl ureas.Analysis of the spectra yielded the chemical shifts.The variations in the chemical shifts have been discussed in terms of the molecular conformations.
- Sudha, L. V.,Sathyanarayana, D. N.
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p. 141 - 146
(2007/10/02)
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- Process for preparing substituted urea derivatives
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A process for the preparation of substituted urea derivatives, and compositions and concentrates for the same purpose are disclosed. According to the process the substituted urea derivatives of formula (I) STR1 wherein R is hydrogen, alkyl, aryl, cycloalkyl or aralkyl, R1 and R2 are hydrogen, alkyl, alkenyl, alkinyl, alkoxy, oxyalkyl, cycloalkyl, aralkyl, alkoxycarbonylalkyl, aryl or heteroaryl, or R1 and R2 together with the adjacent nitrogen atom may form a saturated or unsaturated heterocycle, or a condensed and/or substituted ring system, and said heterocycle or said condensed and/or substituted ring system may contain also a sulfo group, can be manufactured by reacting an amine of formula (II) STR2 with an N-carbamoyl-benzoic acid sulfimide derivative of formula (III) STR3 The disclosed N-acylating composition comprises of from 3 to 60% by weight, preferably of from 5 to 50% by weight sulfimide derivative of formula (III), of from 97 to 40% by weight, preferably of from 95 to 50% by weight solvent, and if desired, an organic or inorganic base. The disclosed N-acylating concentrate comprises of from 60 to 95.5% by weight N-acylating agent of formula (III) and of from 4.5 to 40% by weight additives.
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-
-
- SYNTHESES AND TRANSFORMATIONS OF SOME HETEROCYCLIC HYDROXYLAMINES
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Syntheses of some hydroxylaminoazines, their quaternized derivatives or N-oxides and N-amino compounds are described.Several transformations of these compounds and cyclization reactions are presented.
- Tomazic, Alenka,Tisler, Miha,Stanovnik, Branko
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p. 1787 - 1794
(2007/10/02)
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- Heteroacyl Azides as Acylating Agents for Aromatic or Heteroatomic Amines (1)
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The possibility of formation of substituted heterocyclic amides from heteroacyl azides and aromatic or heteroatomic amines was investigated.Although acylation proceeded in some cases under mild reaction conditions, formation of N,N'-disubstituted ureas was the main process at elevated temperatures.
- Stanovnik, B.,Tisler, M.,Golob, V.,Hvala, I.,Nikolic, O.
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p. 733 - 736
(2007/10/02)
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