19895-44-4Relevant academic research and scientific papers
A Fe3O4?SiO2/Schiff Base/Pd Complex as an Efficient Heterogeneous and Recyclable Nanocatalyst for One-Pot Domino Synthesis of Carbamates and Unsymmetrical Ureas
Inaloo, Iman Dindarloo,Majnooni, Sahar
, p. 6359 - 6368 (2019/11/05)
A palladium-catalyzed domino method for the direct synthesis of carbamates and ureas has been developed by using readily available and economical starting materials (aryl halide, carbon monoxide, sodium azide, amines and alcohols) in a one-pot approach. The domino process underwent carbonylation, Curtius rearrangement, and nucleophilic addition. This protocol provides a step-economical and highly efficient reaction to access the wide range of valuable carbamates, symmetrical and unsymmetrical ureas with high yields under remarkable mild reaction conditions that are important factors in pharmaceutical science, biochemistry and agricultural industries. Furthermore, the magnetically recoverable nanocatalyst (Fe3O4?SiO2/Pd(II)) can be conveniently and swiftly recycled using external magnet and reused at least for seven times without noticeable loss of its catalytic activity.
Synthetic method and application of urea compound
-
Paragraph 0183-0186, (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.
Synthesis and SAR studies of potent H+/K+-ATPase and anti-inflammatory activities of symmetrical and unsymmetrical urea analogues
Rakesh, Kadalipura P.,Darshini, Nanjudappa,Vidhya, Sunnadadoddi L.,Rajesha,Mallesha, Ningegowda
, p. 1675 - 1681 (2017/06/27)
A sequence of symmetrical and unsymmetrical urea derivatives 1–24 were synthesized and characterized by standard spectroscopic techniques. The synthesized analogues were tested for their in vitro H+/K+-ATPase and anti-inflammatory activities. The majority of the compounds showed outstanding activity, compared to that of omeprazole and indomethacin, usual standard drugs of antiulcer and anti-inflammatory, respectively. In particular, hydroxy, methyl, and methoxy derivatives 13–24 were the most active compounds possessing a significant amplify for diverse substituents on the benzene ring thus, contributing positively to gastric ulcer inhibition. Compounds 1–3 and 22–24 showed excellent anti-inflammatory activity due to the presence of electron-withdrawing groups (Cl and F) on the molecule.
An unexpected reaction to methodology: An unprecedented approach to transamidation
Rakesh,Ramesha,Shantharam,Mantelingu,Mallesha
, p. 108315 - 108318 (2016/11/30)
This report describes an unprecedented protocol for the synthesis of N,N′-substituted ureas using a cross-coupling method. Mono substituted ureas were modified by an economically viable and simple method using commercially available isocyanates and sodium hydride as the reagents. In addition, the method involves no expensive metal complexes or catalysts and all reactions are carried out at room temperature. Furthermore, both symmetrical and asymmetrical ureas were successfully obtained in single step reactions with reasonable yields.
The use of aqueous potassium dichloroiodate for the synthesis of ureas
Viana, Gil Mendes,De Sequeira Aguiar, Lúcia Cruz,De Araújo Ferr?o, Jonas,Simas, Alessandro Bolis Costa,Vasconcelos, Marcela Guariento
, p. 936 - 940 (2013/03/13)
We report a straightforward and efficient reaction protocol for the syntheses of substituted ureas via treatment of thioureas with aqueous potassium dichloroiodate (KICl2). By tuning the reaction condition, thioureas bearing activated N-aryl substituents may undergo either selective oxidation or sequential oxidation and iodination, forming iodoaryl ureas in the latter case.
Highly efficient synthesis of ureas and carbamates from amides by iodosylbenzene-induced hofmann rearrangement
Liu, Peng,Wang, Zhiming,Hu, Xianming
experimental part, p. 1994 - 2000 (2012/05/05)
A simple and efficient method for the synthesis of 1,3-disubstituted ureas and carbamates from amides by using iodosylbenzene as the oxidant is described. Symmetric and asymmetric ureas and carbamates can be prepared by this procedure in up to 98 % yield. Ureidopeptides can also be prepared in good yield by this method. A simple and efficient method for the synthesis of 1,3-disubstituted ureas and carbamates from amides by using iodosylbenzene as the oxidant is described. By using this method, heterocyclic products can be easily obtained in excellent yield. Ureidopeptides can also be prepared in good yield by this procedure. Copyright
Phenylureas. Part 1. Mechanism of the basic hydrolysis of phenylureas
Laudien,Mitzner
, p. 2226 - 2229 (2007/10/03)
The mechanism of the hydrolytic decomposition of phenylureas in basic media in the pH range 12 to 14 is investigated. In this pH range a levelling of the rate-pH curve is observed as well as a change of the substituent influence on the hydrolysis rate. These experimental findings suggest the formation of an unreactive side product of the phenylurea in a parasitic side equilibrium at sufficiently high pH. The urea dissociates at the aryl-NH group to give its conjugate base. For the hydrolytic decomposition of phenylureas an addition-elimination mechanism is proposed as has been established for the alkaline hydrolysis of carboxylic acid esters and amides.
Selenium-catalyzed reductive carbonylation of nitrobenzene with amines as coreagents to give unsymmetric phenylureas
Yang, Ying,Lu, Shiwei
, p. 4845 - 4846 (2007/10/03)
The reductive carbonylation of nitrobenzene catalyzed by selenium to yield unsymmetric phenylureas has been studied. When secondary amines were used as coreagents, a single product, PhNHCONR2, was formed; when primary amines were chosen as coreagents, mixed products, including RNHCONHR, RNHCONHPh and PhNHCONHPh, were obtained.
Oxidation of Isothiocyanates to Isocyanates using Dimethyldioxirane; Relevance to Biological Activity of Isothiocyanates
Davidson, Nicola E.,Botting, Nigel P.
, p. 410 - 411 (2007/10/03)
The reaction of organic isothiocyanates with dimethyldioxirane in acetone produces isocyanates in good yields, trapped out as the ureas by reaction with isopropylamine.
