- 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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- Synthesis and characterization of N,N,N-trimethyl-O-(ureidopyridinium)acetyl chitosan derivatives with antioxidant and antifungal activities
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Chitosan is an active biopolymer, and the combination of it with other active groups can be a valuable method to improve the potential application of the resultant derivatives in food, cosmetics, packaging materials, and other industries. In this paper, a series of N,N,N-trimethyl-O-(ureidopyridinium)acetyl chitosan derivatives were synthesized. The combination of chitosan with ureidopyridinium group and quaternary ammonium group made it achieve developed water solubility and biological properties. The structures of chitosan and chitosan derivatives were confirmed by FTIR,1H NMR spectra, and elemental analysis. The prepared chitosan derivatives were evaluated for antioxidant property by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, hydroxyl radical scavenging ability, and superoxide radical scavenging ability. The results revealed that the synthesized chitosan derivatives exhibited improved antioxidant activity compared with chitosan. The chitosan derivatives were also investigated for antifungal activity against Phomopsis asparagus as well as Botrytis cinerea, and they showed a significant inhibitory effect on the selected phytopathogen. Meanwhile, CCK-8 assay was used to test the cytotoxicity of chitosan derivatives, and the results showed that most derivatives had low toxicity. These data suggested to develop analogs of chitosan derivatives containing ureidopyridinium group and quaternary ammonium group, which will provide a new kind of promising biomaterials having decreased cytotoxicity as well as excellent antioxidant and antimicrobial activity.
- Zhang, Jingjing,Tan, Wenqiang,Li, Qing,Dong, Fang,Guo, Zhanyong
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- Synthetic method and application of urea compound
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The invention relates to a synthetic method of a urea compound, comprising the following steps: adding substituted oxazolone and sodium acetate into a methanol solution, and adding substituted amine under the stirring condition, reacting and carrying out column chromatography to obtain the urea compound. The defect that dangerous compounds need to be used during existing synthetic process is overcome, and a one-pot method is adopted to replace an existing reaction with low yield. The method of the invention has mild reaction condition, the operation is simple, raw materials are easily available, and the substrate can be converted into various other useful molecules. The compound has strong practicality, and can be applied to synthesis of the pesticide daimuron, dieresis long and the anti-cancer drug Sorafenib. The invention relates to a green and environmentally-friendly unsymmetrical urea compound synthesis method with simple process and low cost.
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Paragraph 0171-0174
(2019/06/07)
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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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- Selective recognition of sulphate in a Cu(ii) assisted 1D polymer of a simple pentafluorophenyl substituted pyridyl-urea via second sphere coordination
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A pentafluorophenyl (-C6F5) substituted 3-pyridyl urea, L1, is explored extensively to demonstrate SO4 2- binding exclusively via second sphere coordination in the cavity of a 1D polymeric self-assemb
- Akhuli, Bidyut,Ghosh, Pradyut
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p. 5818 - 5825
(2013/07/25)
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- Studying fluorous interactions in a series of coordination compounds derived from mono-pyridyl ligands equipped with hydrogen bonding functionality: Exploiting anion...πF interaction in separating ClO 4- anion from a competing mixture of anions
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A series of coordination compounds (both coordination complexes (CCs) and coordination polymers (CPs)) viz. [Cu(L1)4·(SO 4)·(DMSO)]CC1, [(H2O)2(DMSO)Cd(L1) 2(μ2SO4)(Cd(L1)2·(SO 4)·(DMSO)·(H2O)] CC2, [Cu(L2) 2(H2O)·(Cl)2] CC3, [Cu(L2) 2(μ-SO4)(H2O)]∝CP1, [{Cu(L2)4(μ-SiF6)}·3H2O] ∝CP2, [{Cu(L3)4(ClO4)}·ClO 4·H2O]·CC4, [{Cu(L3)4(H 2O)}·H2O·2BF4] CC5, [{(Cl)Cu(L3)4(μ-Cl)Cu(L3)4}·Cl·H 2O] CC6, [{Cu2(L3)4(μ-Cl) 2·(Cl)2}·H2O] CC7, [Cu(L3) 2(Cl)2] CC8, and [{Cu(L4)4·(H 2O)2}·SO4·5H2O] CC9 derived from ligands equipped with pyridyl and pentafluorophenyl/phenyl moieties along with hydrogen bonding backbone (amide/urea) with CuII/Cd II metal centers have been synthesized and characterized by single crystal X-ray diffraction (SXRD). Their various fluorous interactions along with hydrogen bonding have been investigated. The results show that almost all the coordination compounds except CC9 studied herein display various fluorous interactions; in one such example i.e. in CC4, anion-πF along with other supramolecular interactions (F...F, C-H...F) shapes the supramolecular assembly, which is exploited to separate environmentally relevant perchlorate anion from a competing mixture of anions viz. SO4 2-, NO3-, ClO4-, BF 4-, Cl- by following in situ synthesis of the corresponding coordination compound.
- Banerjee, Subhabrata,Dastidar, Parthasarathi
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p. 9415 - 9428
(2013/11/19)
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- Cu(acac)2-catalyzed N-arylations of phenylurea with aryl boronic acid
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Cu(acac)2 activates aryl boronic acids for the reaction with NH2-phenylurea without additional ligand and heating. The procedure is simple, general, ligand-free, milder than the palladium-catalyzed arylation, and avoids the use of toxic phosphine ligands. Copyright Taylor & Francis Group, LLC.
- Gavade, Sandip,Balaskar, Ravi,Mane, Madhav,Pabrekar, Pramod N.,Mane, Dhananjay
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experimental part
p. 1704 - 1714
(2012/05/05)
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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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- 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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- 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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- 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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- Practical synthesis of unsymmetrical ureas from isopropenyl carbamates
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A very convenient method for the synthesis of unsymmetrical ureas is described, based on isopropenyl carbamates. The synthetic efficiency of traditional methods for urea formation, such as use of phosgene or alkyl and aryl carbamates, is limited by the fo
- Gallou, Isabelle,Eriksson, Magnus,Zeng, Xingzhong,Senanayake, Chris,Farina, Vittorio
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p. 6960 - 6963
(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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- Model studies on a synthetically facile series of N-substituted phenyl-N'-pyridin-3-yl ureas leading to 1-(3-pyridylcarbamoyl) indolines that are potent and selective 5-HT(2C/2B) receptor antagonists
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A model series of 5-HT(2C) antagonists have been prepared by rapid parallel synthesis. These N-substituted phenyl-N'-pyridin-3-yl ureas were found to have a range of 5-HT(2C) receptor affinities and selectivities over the closely related 5-HT(2A) receptor. Extrapolation of simple SAR, derived from this set of compounds, to the more active but synthetically more complex 1-(3-pyridyl-carbamoyl)indoline series allowed us to target optimal substitution patterns and identify potent and selective 5-HT(2C/2B) antagonists. Copyright (C) 1999 Elsevier Science Ltd.
- Bromidge, Steven M.,Dabbs, Steven,Davies, David T.,Davies, Susannah,Duckworth, D.Malcolm,Forbes, Ian T.,Gadre, Angela,Ham, Peter,Jones, Graham E.,King, Frank D.,Saunders, Damian V.,Thewlis, Kevin M.,Vyas, Deepa,Blackburn, Thomas P.,Holland, Vicky,Kennett, Guy A.,Riley, Graham J.,Wood, Martyn D.
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p. 2767 - 2773
(2007/10/03)
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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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- 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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