2387-23-7Relevant articles and documents
Highly efficient ionic liquid-mediated palladium complex catalyst system for the oxidative carbonylation of amines
Shi, Feng,Peng, Jiajian,Deng, Youquan
, p. 372 - 375 (2003)
A highly efficient catalyst system, palladium-ionic liquid, was developed for the carbonylation of amines to give carbamate or urea. The desired products could be precipitated by adding water into the resulting mixture and the catalyst system could be reused with slight loss of catalytic activity. BMImBF4 ionic liquid + Pd(phen)Cl2 was an effective catalytic system for the oxidative carbonylation of aniline to give corresponding carbamate and for the cyclohexyl amine to give urea. The diversity of the ionic liquids could form an optimal homogeneous catalyst system with a specific organometallic toward specific reactions. There existed strong interactions between the ionic liquid and the Pd complex, which might enhance and stabilize the Pd complex catalyst.
Preparation of 5-diaminomethylenebarbiturates by barbituric acid addition to carbodiimides
Jursic, Branko S.,Douelle, Fred,Stevens, Edwin D.
, p. 3427 - 3432 (2003)
Through NMR spectroscopic monitoring of barbituric acid addition to carbodiimide, a general synthetic procedure for the preparation of 5-diaminomethylenebarbiturates (DABA) was developed. This procedure is very simple and applicable to the preparation of large quantities of DABA derivatives. Through an X-ray structural study of one of the DABA derivatives, it was established that these compounds have an ylide-type structure with strong charge separation within the molecule.
Molecular interactions of β-cyclodextrins with monolayers containing adamantane and anthraquinone guest groups
Swiech, Olga,Chmurski, Kazimierz,Bilewicz, Renata
, p. 461 - 466 (2010)
Complexing abilities of β-cyclodextrin (β-CD) towards anthraquinone derivatives in solution and immobilised on gold surfaces were studied by voltammetry. The association constant of β-CD with 1-aminoanthraquinone in solution was found to be 1.03±0.05×103 M-1 hence, smaller than that with anthraquinone. Capping the surface-immobilised N-(1-anthraquinone) lipoamide with β-CD led to decrease in the heterogeneous electron transfer rate constant due to the change in the immediate environment around the electroactive group. To detect the interactions of β-CD with a non-electroactive guest, N-(1-adamantane) lipoamide (AD-Lip), the CD was modified by the attachment of an anthraquinone group as the electroactive marker. The appearance of the voltammetric peak corresponding to the reduction of the anthraquinone side-group indicated the binding of β-CD to the AD-Lip self-assembled in a monolayer on the gold electrode.
Total Synthesis of (+)-3-Demethoxyerythratidinone and (+)-Erysotramidine via the Oxidative Amidation of a Phenol
Paladino, Marco,Zaifman, Joshua,Ciufolini, Marco A.
, p. 3422 - 3425 (2015)
Oxidative amidation chemistry provides a unified route to aromatic Erythrina alkaloids through a sequence that illustrates new principles and improved conditions to effect a crucial eliminative Curtius-Schmidt rearrangement.
Hofer,Schloegl
, p. 443 (1968)
One-pot synthesis of 4-arylidene imidazolin-5-ones by reaction of amino acid esters with isocyanates and α-bromoketones
Haung, Jia-Yun,Barve, Indrajeet J.,Sun, Chung-Ming
, p. 3040 - 3047 (2019)
A simple and new multicomponent reaction for the one-pot synthesis of substituted 4-arylidene imidazolin-5-ones from l-amino acid methyl esters, iso-, isothio- or isoselenocyanates, and α-bromoketones is demonstrated. Isolation of thiohydantoin and 5-benzylidene 2-thioxoimidazolidin-4-one intermediates revealed a possible reaction mechanism. The strategy was further extended to the synthesis of 2-iminothiazolines and 2-thioxoimidazolin-4-ones.
Improvement of warfarin biopharmaceutics by conjugation with poly(ethylene glycol)
Zacchigna, Marina,Di Luca, Gabriella,Cateni, Francesca,Maurich, Venerando
, p. 379 - 384 (2004)
One of the most used and useful polymers, poly(ethylene glycol) (PEG) was used as a carrier for warfarin. The drug-polymer conjugate was freely water soluble at room temperature. The hydrolytic stability of the PEG-warfarin was investigated at physiological pH and confirmed the stability of the conjugate. In vivo release studies demonstrated a good release of parent drug, without the initial high plasma level of warfarin.
Hydrosilane-Assisted Synthesis of Urea Derivatives from CO2and Amines
Zhao, Yulei,Guo, Xuqiang,Si, Zhiyao,Hu, Yanan,Sun, Ying,Liu, Yunlin,Ji, Zhongyin,You, Jinmao
, p. 13347 - 13353 (2020/11/02)
A methodology employing CO2, amines, and phenylsilane was discussed to access aryl- or alkyl-substituted urea derivatives. This procedure was characterized by adopting hydrosilane to promote the formation of ureas directly, without the need to prepare silylamines in advance. Control reactions suggested that FeCl3 was a favorable additive for the generation of ureas, and this 1,5,7-triazabicyclo[4.4.0]dec-5-ene-catalyzed reaction might proceed through nucleophilic addition, silicon migration, and the subsequent formal substitution of silylcarbamate.
METHOD OF PREPARING UREA USING AMINE COMPOUND AND CARBON DIOXIDE
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Paragraph 0073-0075; 0134-0138; 0164-0165; 0168; 0196, (2020/11/14)
Disclosed is a production method of urea using an amine compound and carbon dioxide. The production method of urea includes a step of producing urea by using the amine compound and a 2-pyrrolidone derivative as a solvent and reacting with the carbon dioxide, thereby producing high yield cyclic urea under mild reaction conditions and no catalyst conditions.
