1014-72-8Relevant academic research and scientific papers
Synthesis of unsymmetrical ureas by sulfur-assisted carbonylation with carbon monoxide and oxidation with molecular oxygen under mild conditions
Mizuno, Takumi,Nakai, Takeo,Mihara, Masatoshi
, p. 2492 - 2496 (2009)
With ambient pressure of carbon monoxide and oxygen at room temperature, N,N-dialkyl-N′-arylureas were selectively accessible from secondary amines, aromatic amines, and sulfur in good to excellent yields. For example, N-butyl-N-methyl-N′-(3,4-dichlorophenyl)urea, which is used as a herbicide (neburon), was afforded successfully from butylmethylamine (2 equiv), 3,4-dichloroaniline (1 equiv) and sulfur (1 equiv) in 79% (21.8 g) yield using carbon monoxide (0.1 MPa) and oxygen (0.1 MPa) at 20°C in DMF. Georg Thieme Verlag Stuttgart.
Imidazolin-2-iminato Ligand-Supported Titanium Complexes as Catalysts for the Synthesis of Urea Derivatives
Naktode, Kishor,Das, Suman,Bhattacharjee, Jayeeta,Nayek, Hari Pada,Panda, Tarun K.
, p. 1142 - 1153 (2016)
The reactions of tetrakis(dimethylamido)titanium(IV) [Ti(NMe2)4] with three different imidazolin-2-imines (ImRNH; R = tert-butyl (tBu), mesityl (Mes), and 2,6-diisopropylphenyl (Dipp)) afforded the corresponding titanium i
Bromodimethylsulfonium bromide (BDMS)-mediated Lossen rearrangement: Synthesis of unsymmetrical ureas
Yadav, Deepak K.,Yadav, Arvind K.,Srivastava, Vishnu P.,Watal, Geeta,Yadav, Lal Dhar S.
, p. 2890 - 2893 (2012)
Bromodimethylsulfonium bromide (BDMS) was found to be a very efficient reagent for Lossen rearrangement of hydroxamic acids to the corresponding isocyanates which were subsequently trapped in situ with various amines to afford unsymmetrical ureas in good to excellent yields (64-89%). The protocol is experimentally simple, mild, and represents valuable alternative to the existing methods for in situ activation of hydroxamic acids promoting Lossen rearrangement.
A convenient method of synthesis of unsymmetrical urea derivatives
Groszek, Grazyna
, p. 759 - 761 (2002)
A method for the preparation of unsymmetrical urea derivatives that may contain functional groups such as hydroxyl, amine, amide, and carboxyl is described. The method consists of a one-pot modified Curtius rearrangement starting with appropriate aromatic acid chloride and carried out in a nonaqueous system.
The first aminimide synthesis from benzoyl azide and pyridine
Capuano, Ben,Crosby, Ian T.,Lloyd, Edward J.,Neve, Juliette E.
, p. 214 - 217 (2007)
Irradiation of benzoyl azide 1 at 254 nm in the presence of some amines produces aminimides: in the presence of pyridine the aminimide 13 can be isolated in 41% yield; in the presence of N,N-dimethylaniline a CH insertion product 7 is obtained via an intermediate aminimide 12. This is the first reported synthesis of aminimides from a benzoyl azide. CSIRO 2007.
Hydroamination and Hydrophosphination of Isocyanates/Isothiocyanates under Catalyst-Free Conditions
Zhu, Xiancui,Xu, Mengchen,Sun, Jinrong,Guo, Dianjun,Zhang, Yiwei,Zhou, Shuangliu,Wang, Shaowu
, p. 5213 - 5218 (2021/10/19)
Symmetrical and unsymmetrical N,N’-disubstituted as well as trisubstituted ureas/thioureas by the hydroamination of isocyanates/isothiocyanates, and various phosphathioureas by the hydrophosphination of isothiocyanates have been synthesized in good to excellent yields under catalyst-free and mild conditions. This protocol is also applicable for the efficient synthesis of chiral ureas and thioureas and common herbicides, such as fenuron and monuron.
Visible-light-promoted oxidative desulphurisation: A strategy for the preparation of unsymmetrical ureas from isothiocyanates and amines using molecular oxygen
Deng, Weiseng,Gan, Ziyu,Jiang, Yuan-Ye,Li, Guoqing,Yan, Qiuli,Yang, Daoshan
supporting information, p. 2956 - 2962 (2020/06/17)
A green and efficient visible-light promoted oxidative desulphurisation protocol has been proposed for the construction of unsymmetrical ureas under mild conditions with broad substrate scope and good functional group tolerance. Most appealingly, the reaction can proceed smoothly without adding any strong oxidants. Control experiments and computational studies support a mechanism involving water-assisted in situ generation of thioureas and photocatalytic oxidative desulphurisation. The present method provides a promising synthesis strategy for the formation of diverse and useful unsymmetrical urea derivatives in the fields of pharmaceutical and synthetic chemistry.
Synthetic method and application of urea compound
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Paragraph 0199-0202, (2019/06/07)
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.
Pd/C-catalyzed reductive carbonylation of nitroaromatics for the synthesis of unsymmetrical ureas: One-step synthesis of neburon
Li, Chong-Liang,Peng, Jin-Bao,Qi, Xinxin,Ying, Jun,Wu, Xiao-Feng
supporting information, p. 12472 - 12475 (2018/08/04)
A Pd/C catalyzed reductive carbonylation of nitroarenes for the synthesis of unsymmetrical ureas has been developed. Using inexpensive and stable nitroarenes as the substrates, a series of unsymmetrical ureas were produced in moderate to good yields. A range of functional groups including thioethers, halides and vinyl were compatible with this reaction. As a heterogeneous catalyst, Pd/C was recycled and reused four times without losing activity. Notably, urea-based herbicide neburon was prepared in 64% yield under our standard conditions.
Efficient Direct Halogenation of Unsymmetrical N -Benzyl- and N -Phenylureas with Trihaloisocyanuric Acids
Sanabria, Carlos M.,Costa, Bruno B. S.,Viana, Gil M.,De Aguiar, Lúcia C. S.,De Mattos, Marcio C. S.
supporting information, p. 1359 - 1367 (2017/12/26)
A simple and efficient methodology for the direct halogenation of N -phenylureas was developed using trihaloisocyanuric acids in acetonitrile at room temperature. This protocol proved to be effective for the construction of N -phenylureas with different patterns of substitution. Additionally, less reactive N -benzylureas were halogenated in the presence of a mixture of trifluoroacetic acid and acetonitrile at room temperature.
