نتایج جستجو برای: nitroso
تعداد نتایج: 2476 فیلتر نتایج به سال:
Abstract In this study, we investigated the influence of O 2 , SO and NO x on branched linear polyethyleneimine (PEI) functional silica CO adsorbents (BPEI-SiO LPEI-SiO respectively). was much more likely to oxidize BPEI-SiO compared with form C=O C=N groups led a 23.0% decrease in adsorption capacity after 990 min cumulative contact 10% . contrast, lost only approximately 3.6% its capacity, al...
Aim. To study the frequency and spectrum of cytogenetic disorders in Triticum aestivum L., induced by effect moderate high concentrations N-nitroso-N-methylurea. Methods. The seeds winter wheat cultivars Albatros odeskyi Zymoiarka were treated with water solution N-nitroso-N-methylurea such as 0.005 %, 0.01 0.025 %. A analysis cells a root meristem was made help an anatelophase method. Results....
The title compound is a new pyrazolone derivative which was synthesized starting from p-sulphophenyl-3-methyl-5-pyrazolone (1) by nitrosation at low temperature to afford the corresponding p-sulphophenyl-3-methyl-4-nitroso-5-pyrazolone can exist both in nitroso (2a) and oxime tautomeric forms (2b). Reduction of latter using zinc with hydrochloric acid furnished 4-amino-p-sulphophenyl-3-methyl-5...
A metal-free tandem reaction, initiated by the generation of a diazonium cation and followed by cycloetherification, was developed. Acid-promoted de-tert-butylation of N-nitroso N-tert-butylamine was used to generate a diazonium cation in situ, demonstrating a new application of nitroso chemistry. This reaction was employed in the synthesis of substituted benzofuran-3(2H)-ones and dihydrobenzo[...
A series of 10,13-disubstituted 16-membered macrolides was synthesized using nitroso Diels-Alder reactions of leucomycin A7. Despite the extensive constituent functionalities in leucomycin, the hetero cycloaddition reactions proceeded in a highly regio- and stereoselective fashion. Subsequent chemical modifications of the nitroso cycloadducts, including N-O bond reduction, were also conducted. ...
Nitrosatability of dried Nigerian vegetables and spices was investigated under simulated gastric conditions. N-Nitroso-dimethylamine (NDMA) was the only volatile nitrosamine found above the preformed level except in ugwu where N-nitroso-piperidine (2.3 ppb) was also detected. The lowest NDMA value of 0.4 ppb was found in bitterleaf while onions had the highest level (14.7 ppb) of nitrosation. T...
The recombinant fragment of von Willebrand factor (vWF) spanning Ala444 to Asp730 and containing an Arg545Cys mutation (denoted AR545C) has antithrombotic properties that are principally a consequence of its ability to inhibit platelet adhesion to subendothelial matrix. Endothelial-derived nitric oxide (NO) can also inhibit platelet function, both as a consequence of inhibiting adhesion as well...
Chiral nonracemic aminated nitroso acetals were synthesized via diastereoselective multicomponent [4 + 2]/[3 + 2] cycloadditions employing new (S,E)-γ-nitrogenated nitroalkenes 5a-c as heterodienes, ethyl vinyl ether (EVE) as a dienophile, and selected electron-deficient alkenes as 1,3-dipolarophiles. The employment of different organic solutions of LiClO4 or LiCl as promoter systems provided t...
This review is focused on the dimerization and dissociation of aromatic C-nitroso compounds and their dimers, the reactions that could be used as a convenient model for studying the thermal organic solid-state reaction mechanisms. This molecular model is simple because it includes formation or breaking of only one covalent bond between two nitrogen atoms. The crystalline molecular solids of nit...
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