oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Synthesis of Bis-ureas from Bis(o-nitrophenyl) Carbonate  [PDF]
Maria-Cristina Turoczi,Monika Simon,Valentin Badea,Carol Csunderlik
Molecules , 2008, DOI: 10.3390/molecules13123192
Abstract: A general method for the preparation of bis-ureas from bis(o-nitrophenyl) carbonate has been developed. Directional urea synthesis is achieved by sequential amine addition to bis(o-nitrophenyl) carbonate in two steps: in the first step bis(o-nitrophenyl) carbonate is reacted with benzylamine to form benzyl-o-nitrophenyl carbamate; in the second step the carbamate is reacted with a variety of diamines in toluene to yield bis-ureas.
Carbolithiation of N-alkenyl ureas and N-alkenyl carbamates
Julien Lefranc,Alberto Minassi,Jonathan Clayden
Beilstein Journal of Organic Chemistry , 2013, DOI: 10.3762/bjoc.9.70
Abstract: N-Alkenyl ureas and N-alkenyl carbamates, like other N-acyl enamines, are typically nucleophilic at their β-carbon. However, by incorporating an α-aryl substituent, we show that they will also undergo attack at the β-carbon by organolithium nucleophiles, leading to the products of carbolithiation. The carbolithiation of E and Z N-alkenyl ureas is diastereospecific, and N-tert-butoxycarbonyl N-alkenyl carbamates give carbolithiation products that may be deprotected in situ to provide a new connective route to hindered amines.
Interaction of Thioamides, Selenoamides, and Amides with Diiodine  [PDF]
Sotiris K. Hadjikakou,Nick Hadjiliadis
Bioinorganic Chemistry and Applications , 2006, DOI: 10.1155/bca/2006/60291
Abstract: We review the results of our work on the iodine interaction with thioamides, selenoamides, and amides. Complexes with (i) “spoke” or “extended spoke” structures, D⋅I2 and D⋅I2⋅I2, respectively, (D is the ligand donor) (ii) iodonium salts of {[D2−I]
Synthesis of Novel Aryl(heteroaryl)sulfonyl Ureas of Possible Biological Interest  [PDF]
Franciszek S?czewski,Anna Kuchnio,Monika Samsel,Marta ?obocka,Agnieszka Kiedrowska,Karolina Lisewska,Jaros?aw S?czewski,Maria Gdaniec,Patrick J. Bednarski
Molecules , 2010, DOI: 10.3390/molecules15031113
Abstract: The course of reaction of aryl and heteroaryl sulfonamides with diphenylcarbonate (DPC) and 4-dimethylaminopyridine (DMAP) was found to depend on the pKa of the sulfonamide used. Aryl sulfonamides with pKa ~ 10 gave 4-dimethylamino-pyridinium arylsulfonyl-carbamoylides, while the more acidic heteroaryl sulfonamides (pKa ~ 8) furnished 4-dimethylaminopyridinium heteroarylsulfonyl carbamates. Both the carbamoylides and carbamate salts reacted with aliphatic and aromatic amines with the formation of appropriate aryl(heteroaryl)sulfonyl ureas, and therefore, can be regarded as safe and stable substitutes of the hazardous and difficult to handle aryl(heteroaryl)sulfonyl isocyanates.
New GABA amides activating GABAA-receptors  [cached]
Peter Raster,Andreas Sp?th,Svetlana Bultakova,Pau Gorostiza
Beilstein Journal of Organic Chemistry , 2013, DOI: 10.3762/bjoc.9.42
Abstract: We have prepared a series of new and some literature-reported GABA-amides and determined their effect on the activation of GABAA-receptors expressed in CHO cells. Special attention was paid to the purification of the target compounds to remove even traces of GABA contaminations, which may arise from deprotection steps in the synthesis. GABA-amides were previously reported to be partial, full or superagonists. In our hands these compounds were not able to activate GABAA-receptor channels in whole-cell patch-clamp recordings. New GABA-amides, however, gave moderate activation responses with a clear structure–activity relationship suggesting some of these compounds as promising molecular tools for the functional analysis of GABAA-receptors.
Genetic and Epigenetic Regulation of CCR5 Transcription  [PDF]
Rutger J. Wierda,Peter J. van den Elsen
Biology , 2012, DOI: 10.3390/biology1030869
Abstract: The chemokine receptor CCR5 regulates trafficking of immune cells of the lymphoid and the myeloid lineage (such as monocytes, macrophages and immature dendritic cells) and microglia. Because of this, there is an increasing recognition of the important role of CCR5 in the pathology of (neuro-) inflammatory diseases such as atherosclerosis and multiple sclerosis. Expression of CCR5 is under the control of a complexly organized promoter region upstream of the gene. The transcription factor cAMP-responsive element binding protein 1 (CREB-1) transactivates the CCR5 P1 promoter. The cell-specific expression of CCR5 however is realized by using various epigenetic marks providing a multivalent chromatin state particularly in monocytes. Here we discuss the transcriptional regulation of CCR5 with a focus on the epigenetic peculiarities of CCR5 transcription.
Cyclization-Carbonylation-Cyclization Coupling Reaction of Propargyl Ureas with Palladium(II)-Bisoxazoline Catalyst  [PDF]
Taichi Kusakabe,Koujiro Kawaguchi,Miya Kawamura,Naohiko Niimura,Rong Shen,Hiroyuki Takayama,Keisuke Kato
Molecules , 2012, DOI: 10.3390/molecules17089220
Abstract: The cyclization-carbonylation-cyclization coupling reaction (CCC-coupling reaction) of propargyl ureas catalyzed by PdII(box) complexes afforded symmetrical ketones bearing two 2-amino-2-oxazoline groups in good to moderate yields.
Studies on nitrogen release dynamics of new coated ureas.
新型包膜尿素的氮释放动态研究

YE Xue-zhu,MA Jun-wei,HE Nian-zu,YU Qiao-gang,
叶雪珠
,马军伟,何念祖,俞巧钢

浙江大学学报(农业与生命科学版) , 2000,
Abstract: Coated ureas(CUs:CU1, CU2) were made of normal granular urea by coating with organic polymer layers in different thickness the nitrogen release rate of CUs were determined in lab under different conditions,The results obtained showed that: Coated ureas were all slow release fertilizers The thicker the polymer layer was, the slower its nutrient released; The ammonia volatilization and nitrogen leachate reduced from CUs compared with normal urea; The content of ions in the environment affected the release rate of nitrogen of CUs
Fast Solvent-free Alkylation of Amides and Lactams under Microwave Irradiation
Dariusz Bogdal
Molecules , 1999, DOI: 10.3390/41100333
Abstract: N-Substituted amides and lactams are rapidly N-alkylated under solvent-free phase-transfer catalytic conditions using microwaves.
NEW AMIDES OF SULPHONAMIDES: SYNTHESIS AND BIOLOGICAL EVALUATION
HUSAIN,ASIF; AHMAD,AUSAF; MUJEEB,M; AKHTER,MYMOONA;
Journal of the Chilean Chemical Society , 2010, DOI: 10.4067/S0717-97072010000100017
Abstract: a series of amide-derivatives has been synthesized by establishing an amide linkage (-conh-) between appropriate sulphonamide moiety and different 3-(4-substituted-benzoyl) propionic acids through one-pot reaction. the structures of the newly synthesized compounds were established on the basis of modern analytical techniques. these amides were evaluated for their antiinflammatory, ulcerogenic and antibacterial activities. some of the compounds showed good antiinflammatory activity. additionally, these derivatives were very low in their ulcerogenic action.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.