- Di-tert-butyl peroxide (DTBP)-mediated synthesis of symmetrical N,N′-disubstituted urea/thiourea motifs from isothiocyanates in water
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ABATRACT: A direct approach to N,N′-disubstituted urea/thiourea from the self-condensation reactions of isothiocyanates in water has been developed. This access tolerated a wide range of functional groups on the aromatic ring, providing a practical and environment-friendly process to N,N′-disubstituted urea/thiourea in moderate to excellent yields from safe and easily available starting materials. A plausible mechanism of the desulfurization self-condensation reaction for urea was also proposed and the role of di-tert-butyl peroxide (DTBP) and copper catalyst in the present strategy was demonstrated with the help of ESI mass spectrometry of intermediate studies.
- Chen, Ling,Dong, Yibo,Wu, Yangjie,Yang, Jinchen,Zhang, Jinli
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supporting information
(2021/12/01)
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- Palladium catalyzed carbonylative annulation of the C(sp2)-H bond of N,1-diaryl-1H-tetrazol-5-amines and N,4-diaryl-4H-triazol-3-amines to quinazolinones
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Pd(ii) catalyzed direct C-H carbonylative annulation of N,1-diaryl-1H-tetrazol-5-amines and N,4-diaryl-4H-1,2,4-triazol-3-amines gave the corresponding triazole and tetrazole fused quinazolinones in good yields. This methodology offers a convenient method for the synthesis of these important heterocyclic scaffolds in a highly atom economical process. On the mechanistic aspect weakly nucleophilic triazole and tetrazole moieties function as both directing as well as intramolecular nucleophiles. The catalytically active C-H activated intermediate dimeric Pd complex was isolated and characterized which on exposure to CO gas gave the corresponding tetrazole fused quinazolinone derivative. On the basis of isolation of the intermediate and observed kinetic isotope effects, a mechanism has been proposed for the C-H activated direct carbonylative annulation reaction.
- Chandrasekhar, Attoor,Ramkumar, Venkatachalam,Sankararaman, Sethuraman
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supporting information
p. 8629 - 8638
(2018/12/12)
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- Novel self-condensation of ammonium dithiocarbamates leading to symmetrical substituted thioureas
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For the first time, the formation of symmetrical substituted thiourea analogues generated by the selfcondensation of trialkylammoniumdithiocarbamates is reported. The reactions occurred under mild conditions. The method allows the use of amines possessing a weak nucleophilic feature in good yields. The highlight of the study is a novel self-condensation mechanism based on dithiocarbamates as a basic compound in organic chemistry.
- üng?ren, ?evket Hakan,S?r?a, Fatih
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supporting information
p. 28 - 33
(2016/12/24)
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- A simple route for the synthesis of symmetrical thiourea derivatives and amidinium cations by reaction between isocyanides, amines and carbon disulfide
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Reaction between primary amines and CS2 promoted by alkyl isocyanides in ethanol as solvent provides a simple and efficient route for the synthesis of symmetrical thiourea derivatives. The reaction of secondary amines with carbon disulfide and alkyl isocyanides afforded new amidinium cations in good yields.
- Anary-Abbasinejad, Mohammad,Karimi, Nadia,Mehrabi, Hossein,Ranjbar-Karimi, Reza
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p. 653 - 659
(2013/02/22)
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- Efficient method of synthesis of N,N′-disubstituted ureas/thioureas by a Zinc chloride catalyzed thermal reaction
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Symmetrically N,N'-disubstituted ureas/thioureas were synthesized by heating amines or phenyl hydrazine and urea/thiourea on a preheated hot plate at 80-85C under solvent-free conditions in the presence of a catalytic amount of ZnCl2 as a catalyst. The protocol has the advantages of not using toxic phosgene and other hazardous substrates or organic solvents. Increased reaction rate, good yield, and a simple workup procedure are involved.
- Pasha,Madhusudana Reddy
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experimental part
p. 2928 - 2934
(2009/12/03)
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- New potent imidazoisoquinolinone derivatives as anti-Trypanosoma cruzi agents: Biological evaluation and structure-activity relationships
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A series of novel benzoimidazo and N-aryl-5-oxo-imidazo[1,2-b]isoquinoline-10-carbothioamides was developed. All the compounds were evaluated for their in vitro action against the epimastigote form of Trypanosoma cruzi. Four of them showed higher activity than Nifurtimox. Their unspecific cytotoxicity was evaluated using HeLa and L6 cells, being non-toxic at concentrations at least 15 and 200 times higher than that of T. cruzi IC50. To gain insight into the mechanism of action, their DNA binding properties and reactivity with glutathione were studied, and QSAR study was performed.
- Bollini, Mariela,Casal, Juan Jose,Alvarez, Diego E.,Boiani, Lucia,Gonzalez, Mercedes,Cerecetto, Hugo,Bruno, Ana Maria
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experimental part
p. 1437 - 1444
(2009/09/25)
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- Efficient synthesis of N,N′-disubstituted ureas/thioureas catalyzed by iodine
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Iodine is an efficient catalyst for the synthesis of symmetrically N,N′-disubstituted ureas/thioureas by heating respective amines or phenyl hydrazine and urea/thiourea on a preheated hot plate at 90-95°C, under solvent-free conditions. The yields are excellent, and the reactions go to complete within 5-10 min. Copyright Taylor & Francis Group, LLC.
- Pasha,Jayashankara
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p. 1787 - 1793
(2007/10/03)
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- An environmentally benign method for the synthesis of symmetrical N,N′-disubstituted thioureas in a water medium
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An environmentally benign method for the synthesis of symmetrical N,N′-disubstituted thioureas in a water medium using poly(ethylene glycol)-400 (PEG-400) as a catalyst and a microwave as a heating source is described. Diaryl- and dialkyl-thioureas efficiently are synthesized by the reactions of thiourea with a variety of amines. This protocol has advantages of (a) no use of hazardous reagents and volatile organic solvents, (b) a rapid reaction rate, (c) a high yield, and (d) a simple work-up procedure. Copyright Taylor & Francis Inc.
- Li, Zheng,Wang, Zhi-Yuan,Zhao, Yan-Long,Xing, Yu-Lin,Zhu, Wei
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p. 2745 - 2750
(2007/10/03)
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- Enzyme induction and comparative oxidative desulfuration of isothiocyanates to isocyanates
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Enzyme induction of oxidative metabolism of isothiocyanates to isocyanates by rat liver microsomes and comparative metabolic conversion of some isothiocyanates were investigated. Metabolic activity was assayed by trapping the isocyanate metabolites from isothiocyanates with the inclusion of 2-aminofluorene to form the respective mixed ureas as previously described for the 2-naphthyl isothiocyanate. Male F344 rats were fed either a conventional grain diet for induction with Aroclor 1254 or AIN 76A diet without antioxidant beginning 2 weeks before treatment with Aroclor 1254, β- naphthoflavone, isosafrole, or phenobarbital. Enzymes responsible for the metabolism of 1- and 2-naphthyl isothiocyanate were inducible by all four agents, Aroclor being the best under the current induction protocol and metabolic conversion assay procedure. On the other hand, enzymes responsible for the metabolism of benzyl isothiocyanate were induced only by Aroclor and, to a lesser extent, by phenobarbital. For the comparative metabolic conversion studies, using the microsomes from Aroclor-treated rats fed a conventional grain diet, the rates of metabolic conversion followed the order of 1-naphthyl >> phenyl > benzyl and phenethyl >> propyl, ethyl, and methyl isothiocyanates.
- Lee, Mei-Sie
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p. 1072 - 1078
(2007/10/03)
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- THERMOLYSIS AND PHOTOLYSIS OF SOME THIOUREA DERIVATIVES (PART I)
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Thermolysis od N-benzoyl-N'-phenylthiourea (BPTU) on heating in air at 230 deg C gives NH3, H2S, benzaldehyde, benzil, aniline, azobenzene, benzamide, benzanilide, phenylisothiocyanate, phenylcyanamide, thiocarbanilide and benzoylisothiocyanate, whereas thermolysis of N-benzoyl-N'-benzylthiourea (BBTU) affords NH3, H2S, benzaldehyde, benzil, toluene, bibenzyl, stilbene, benzamide, cyanamide, benzylisothiocyanate, benzoylthiourea and benzoylisothiocyanate.Thermolysis of N-benzoyl-N'-α-naphthylthiourea (BNTU) under the same conditions gives NH3, H2S, benzaldehyde, benzil, benzamide, α-naphthylisothiocyanate, α-naphthanilide, α-naphthylcyanamide, benzoylisothiocyanate, α-naphthylamine and N,N'-di-α,α'-naphthylthiourea.Analogous results were also obtained on photolysis of (BPTU), (BBTU) and (BNTU) with the exception of NH3 and the photodegradation products of phenylthiourea, benzylthiourea and α-naphthylthiourea respectively.The main feature of these pyrolyses is the homolysis of the amide and thioamide bonds providing free radicals that undergo different reactions involving H-abstraction, dimerization, coupling, fragmentation, rearrangement and disproportionation to yield the identified products.
- Aly, M. M.,Fahmy, A. M.,Gaber, A. M.
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p. 253 - 258
(2007/10/02)
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- Applications of Phase Transfer Catalysis, 26. - Thioureas by Three-Component Reactions of Amines, Carbon Tetrachloride, and Sulfide Ions
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The title reactions proceed exothermically in the presence of a phase transfer catalyst.Thiophosgene is an intermediate in this conversion, and its phase transfer catalytic transformation into carbon disulfide and trithiocarbonate can be demonstrated.Perchloromethanethiol/sodium sulfide and a PT catalyst yield thiophosgene too.Activated vicinal dibromides were debrominated by Na2S/catalyst.
- Broda, Witold,Dehmlow, Eckehard V.
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p. 1839 - 1843
(2007/10/02)
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