102-07-8Relevant articles and documents
Desulfurization of N,N'-Diarylthioureas by Lead Tetraacetate Oxidation
Debroy, Abhijit,Nandy Mazumdar, Sujit,Barua, Parag D.,Mahajan, Mahinder P.
, p. 315 - 316 (1984)
Lead tetraacetae oxidation of N,N'-diarylthioureas in refluxing dichloromethane and pyridine gave the corresponding N,N'-diarylureas.Sulfur was isolated during each oxidation reaction.
-
Wakeshima,Kijima
, p. 953 (1975)
-
CeO2-catalyzed direct synthesis of dialkylureas from CO2 and amines
Tamura, Masazumi,Ito, Kazuki,Nakagawa, Yoshinao,Tomishige, Keiichi
, p. 75 - 85 (2016)
CeO2 showed higher activity for the direct synthesis of 1,3-dibutylurea (DBU) from CO2 and n-butylamine than the metal oxides tested. The solvent largely influenced the reaction over CeO2, and N-methylpyrrolidone (NMP) was preferable among various solvents tested from the viewpoints of activity and selectivity. The catalyst system composed of CeO2 catalyst and NMP solvent (CeO2 in NMP) was applicable to the reactions of various amines such as linear primary alkylamines or branched primary alkylamines, although tert-butylamine afforded low conversion. In contrast, secondary amines and aniline provided no yield of the ureas. The combination of 2-cyanopyridine with CeO2 in NMP (CeO2 in NMP with 2-cyanopyridine) promoted the transformation of the unreactive amines, showing that tert-butylamine and aniline were converted to the corresponding ureas in 82% and 80% yields, respectively. These yields are much higher than those reported in the previous literatures, indicating that CeO2 in NMP with 2-cyanopyridine drastically promoted transformation of amines with low reactivity.
-
Haruki,E. et al.
, p. 1361 - 1367 (1968)
-
Annulation Reactions of In-Situ-Generated N-(Het)aroyldiazenes with Isothiocyanates Leading to 2-Imino-1,3,4-oxadiazolines
Zhao, Qiongli,Ren, Linning,Hou, Jiao,Yu, Wenquan,Chang, Junbiao
, p. 210 - 213 (2019)
A novel annulation reaction of N-(het)aroyldiazenes and isothiocyanates has been established. This transformation involves a sequential cyclization and desulfurization/intramolecular rearrangement to produce 2-imino-1,3,4-oxadiazolines. The less-stable N-(het)aroyldiazenes can be conveniently generated in situ by I2-mediated oxidation of hydrazides, which allows a one-pot synthesis of the products directly from readily accessible hydrazide and isothiocyanate substrates. This operationally simple synthetic process requires no use of malodorous isocyanides and can be conveniently conducted on a gram scale.
A convenient and inexpensive method for conversion of thiocarbonyl compounds to their oxo derivatives using oxone under solvent-free conditions
Mohammadpoor-Baltork, Iraj,Sadeghi, Majid M.,Esmayilpour, Karim
, p. 953 - 959 (2003)
A series of thioamides, thioureas and thioesters are transformed to their corresponding carbonyl compounds in good to excellent yields with oxone under solid phase conditions, while thioketones remained unchanged under these conditions.
N-heterocyclic carbene - Palladium complexes as efficient catalysts for the oxidative carbonylation of amines to ureas
Zheng, Shuzhan,Peng, Xingao,Liu, Jianming,Sun, Wei,Xia, Chungu
, p. 1471 - 1476 (2007)
A highly efficient oxidative carbonylation reaction of amines to ureas was developed making use of carbene-palladium complexes in the absence of any promoter. Both aliphatic amines and aromatic amines were transformed in good to excellent yields to the expected ureas.
Novel Route from Thiocarbamate to Isocyanate: 2,2,2-Trinitroethyl Isocyanate
Sitzmann, Michael E.,Gilligan, William H.
, p. 5879 - 5881 (1985)
-
Synthesis of symmetrical ureas by (Diacetoxyiodo)benzene-induced hofmann rearrangement
Landsberg, Dirk,Kalesse, Markus
, p. 1104 - 1106 (2010)
Amides undergo Hofmann rearrangement by treatment with (diacetoxyiodo) benzene (DAIB) to provide symmetrical ureas in a simple and robust transformation. Georg Thieme Verlag Stuttgart - New York.
Photochemical molecular storage of Cl2, HCl, and COCl 2: Synthesis of organochlorine compounds, salts, ureas, and polycarbonate with photodecomposed chloroform
Kuwahara, Yuki,Zhang, Ailing,Soma, Haruka,Tsuda, Akihiko
, p. 3376 - 3379 (2012)
Chloroform is available as not only an organic solvent but also photochemical molecular storage for synthetically important chemicals such as Cl2, HCl, and COCl2. We have succeeded in synthesizing organochlorine compounds, hydrochloric salt of amines, ureas, organic carbonates, and polycarbonate in practical high yields with photodecomposed chloroform.
Hypervalent Iodine Reagent-Promoted Hofmann-Type Rearrangement/Carboxylation of Primary Amides
Wang, Xia,Yang, Peng,Hu, Bo,Zhang, Qian,Li, Dong
, p. 2820 - 2826 (2021)
A novel transformation of primary amides to secondary amides promoted by hypervalent iodine reagents was developed. The hypervalent iodine reagent-mediated Hofmann-type rearrangement generated an isocyanate intermediate, which was subsequently trapped by an in situ generated carboxylic acid from the hypervalent iodine reagent to provide the corresponding secondary amides. This method provided a facile and efficient route for the synthesis of secondary amides from primary amides and also revealed novel reactivities of hypervalent iodine reagents.
Copper-catalyzed arylation of phenylurea using KF/Al2O3
Hosseinzadeh, Rahman,Sarrafi, Yaghoub,Mohadjerani, Maryam,Mohammadpourmir, Fatemeh
, p. 840 - 843 (2008)
A mild and efficient method for the copper-catalyzed arylation of phenylurea is described. The coupling reaction of phenylurea with different functionalized aryl iodides in the presence of air stable CuI, N,N′-dibenzylethylenediamine as a ligand, and KF/Al2O3 as a base gives symmetrical and unsymmetrical diarylureas in relatively high yields.
Silica gel confined ionic liquid + metal complexes for oxygen-free carbonylation of amines and nitrobenzene to ureas
Shi, Feng,Zhang, Qinghua,Gu, Yanlong,Deng, Youquan
, p. 225 - 230 (2005)
A new kind of silica gel confined ionic liquid containing a metal complex as heterogenized catalysts was prepared for the carbonylation of amines and nitrobenzene without molecular oxygen to afford the corresponding ureas with greatly enhanced catalytic activity (TOF exceeded 11000 mol·mol -1· h-1), with a much lower amount of ionic liquids being needed, with easy catalyst separation and possible reusability, and avoidance of the using of explosive CO + O2 gas mixtures. Such an enhancement in catalytic activity may be derived from the effect of a high concentration of ionic liquid containing a metal complex due to the confinement into the nanopores or cavities of the silica gel matrix.
Oxidative carbonylation of aniline with new cobalt catalytic systems
Orejon, Aranzazu,Castellanos, Aida,Salagre, Pilar,Castillon, Sergio,Claver, Carmen
, p. 764 - 768 (2005)
New neutral cobalt(II) complexes containing 2,9-bis(2-hydroxyphenyl)-1,10- phenanthroline and 2,9-bis(2-hydroxyphenyl)-2,2′-bipyridine ligands have been synthesized. These complexes are active catalysts in the oxidative carbonylation of aniline in 1-butanol and NaI as a promoter. The principal products obtained are N,N′-diphenylurea and 1-butyl-N-phenylcarbamate.
Squaramides as potent transmembrane anion transporters
Busschaert, Nathalie,Kirby, Isabelle L.,Young, Sarah,Coles, Simon J.,Horton, Peter N.,Light, Mark E.,Gale, Philip A.
, p. 4426 - 4430 (2012)
Square peg in a round ball: Squaramides are shown to be potent transmembrane anion transporters for both chloride and bicarbonate, performing better than the thiourea and urea analogues. Studies into the nature of this transport point to a mobile carrier mechanism, where the squaramide delivers the anion cargo across the lipid bilayer (see scheme, green sphere=anion). These drug-like molecules provide a platform for the development of a new generation of anion-transport systems. Copyright
Ionic liquids/ZnO nanoparticles as recyclable catalyst for polycarbonate depolymerization
Iannone, Francesco,Casiello, Michele,Monopoli, Antonio,Cotugno, Pietro,Sportelli, Maria Chiara,Picca, Rosaria Anna,Cioffi, Nicola,Dell'Anna, Maria M.,Nacci, Angelo
, p. 107 - 116 (2017)
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).
Cragg, R. H.,Greenwood, N. N.
, (1967)
Synthesis of high-performance polyurethanes with rigid 5-6-5-fused ring system in the main chain from naturally occurring myo-inositol
Sudo, Atsushi,Shibata, Yoshiya,Miyamoto, Ayano
, p. 3956 - 3963 (2013)
A bisketal of myo-inositol was used as a diol-type monomer for synthesis of polyurethanes. The monomer was obtained by treatment of myo-inositol with 1,1-dimethoxycyclohexane in the presence of p-toluenesulfonic acid as a catalyst. The ketalization resulted in the formation of a 5-6-5-fused ring system, which endowed the diol-type monomer with high rigidity. The diol readily reacted with diisocyanate to give the corresponding polyurethane, which exhibited excellent heat resistance due to the rigid 5-6-5 system in the main chain. Copyright
-
Kondo et al.
, p. 307 (1972)
-
Conversion of thioamides into their corresponding oxygen analogues using silver carbonate supported on celite
Movassagh,Lakouraj,Gholami
, p. 1507 - 1511 (2003)
Silver carbonate supported on celite (Ag2CO3/Celite) is used as a mild heterogeneous reagent for conversion of a variety of thioamides into their corresponding amides in acetonitrile at room temperature.
PLATINUM COMPLEX CATALYZED SYNTHESIS OF UREA DERIVATIVES FROM NITROARENES AND AMINES UNDER CARBON MONOXIDE
Tsuji, Yasushi,Takeuchi, Ryo,Watanabe, Yoshihisa
, p. 249 - 256 (1985)
N,N'-Diarylureas were obtained in good yields from nitroarenes and aminoarenes at 140 deg C under carbon monoxide (initial 60 kg cm-2) in the presence of a catalytic amount of dichlorobis(triphenylphosphine)platinum(II), the yields of N,N'-diphenylurea, N,N'-bis(4-methylphenyl)urea, and N,N'-bis(4-chlorophenyl)urea were 65, 67 and 61percent, respectively.Benzimidazole derivatives were obtained by the intramolecular cyclization reaction.An attempted synthesis of unsymmetric ureas resulted in the formation of a mixture of symmetric and unsymmetric products.
Microwave assisted, ligand free, copper catalyzed reaction of aryl halides with phenyl urea
Gavade, Sandip N.,Balaskar, Ravi S.,Mane, Madhav S.,Pabrekar, Pramod N.,Shingare, Murlidhar S.,Mane, Dhananjay V.
, p. 292 - 295 (2011)
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.
Mo-ZrO2 solid acid catalyst for synthesis of substituted diphenylureas
Reddy, Benjaram M.,Reddy, Vangala R.
, p. 2789 - 2794 (1999)
Synthesis of substituted diphenylureas from substituted anilines and β- ketoester by using an efficient eco-friendly Mo-ZrO2 solid acid catalyst is described.
Alternatives to phosgene and carbon monoxide: Synthesis of symmetric urea derivatives with carbon dioxide in ionic liquids
Shi, Feng,Deng, Youquan,SiMa, Tianlong,Peng, Jiajian,Gu, Yanlong,Qiao, Botao
, p. 3257 - 3260 (2003)
Simple, clean, safe, reproducible, and practical describes the synthesis of disubstituted urea derivatives, which are effectively synthesized from amines and carbon dioxide with a CsOH/ionic-liquid catalyst system. The products are easily separated and the catalytic system can be reused without deactivation (see picture).
Efficient synthesis of N,N′-disubstituted ureas/thioureas catalyzed by iodine
Pasha,Jayashankara
, p. 1787 - 1793 (2006)
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.
1,4,2-Dioxazol-5-ones as Isocyanate Equivalents: Chemoselective Non-Metal-Catalyzed Carboxamidation of Indoles
Vala, Anand,Parmar, Deepa,Rayani, Rahul,Kusurkar, Rakesh,Guduru, Ramakrishna,Kaneriya, Uttam,Gondaliya, Uday,Parmar, Nirali,Soni, Jigar Y.
, (2022/02/21)
1,4,2-Dioxazol-5-ones are known to undergo decarboxylation under thermal conditions followed by Lossen s rearrangement to give isocyanates. Described herein is the in situ trapping of the isocyanates by indoles to give indole-3-carboxamides in good to exc
1,4,2-Dioxazol-5-ones as Isocyanate Equivalents: An Efficient Synthesis of 2-Quinolinones via β-Keto Amides
Vala, Anand,Parmar, Nirali,Soni, Jigar Y.,Kotturi, Sharadsrikar,Guduru, Ramakrishna
, p. 2080 - 2084 (2021/10/07)
Under thermal conditions, 1,4,2-dioxazol-5-ones are known to undergo decarboxylation followed by Lossen's rearrangement to yield isocyanates. Described herein is the in situ trapping of the resulting isocyanates with carbon nucleophiles to synthesize β-keto amides. Furthermore, a general and mild method for the conversion of the resulting β-keto amides into quinolin-2-ones is reported.
Chromium-catalyzed ligand-free amidation of esters with anilines
Chen, Changpeng,Ling, Liang,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 762 - 766 (2021/04/14)
Amides are important structural motifs in pharmaceutical and agrochemical chemistry because of the intriguing biological active properties. We report here the amidation of commercially available esters with anilines that was promoted by low-cost and air-stable chromium(III) pre-catalyst combined with magnesium, providing access to amides. This reaction occurs without the use of external ligands in a simple operation. Mechanistic studies indicate that a reactive aminated Cr species responsible for the amidation can be considered, which may be formed by reaction of low-valent Cr with aniline followed by reduction with hydrogen evolution.