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61.
The paper shows a computer-assisted procedure for the optimization of selectivity of two columns coupled in series by tuning the working temperature (using the isothermal mode) and columns coupling-point pressure at constant inlet and outlet carrier gas pressures. The optimization procedure validation was tested by the separation of 32 hydrocarbons in a column series with the aim to resolve the maximum number of components in the shortest possible analysis time.Dedicated to Professor J. F. K. Huber on the occasion of his 65th birthday 相似文献
62.
I. B. Dzvinchuk 《Chemistry of Heterocyclic Compounds》2007,43(4):474-479
The reactions of p-(dimethylamino)benzaldehyde with 5-amino-3-methyl-1-phenylpyrazole and 2-RCOCH2-1H-benzimidazoles have produced 5-(1H-benzimidazol-2-yl)-1H-pyrazolo[3,4-b]pyridines. The transformation includes the formation
of compounds in accordance with a Hantzsch reaction containing a 1,4-dihydropyridine ring, and is completed by the aromatization
either by the splitting off of N,N-dimethylanyline or oxidation. The splitting is produced by acetic acid and the oxidation
by a nitrocompound.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 578–584, April 2007. 相似文献
63.
I. B. Dzvinchuk A. V. Vypirailenko M. O. Lozinskii 《Chemistry of Heterocyclic Compounds》2004,40(9):1199-1206
Oxidative cyclocondensation of 2-aroylmethyl-1H-benzimidazoles with o-aminothiophenol gave the previously unknown 3-aryl-2-(2-benzimidazolyl)-4H-1,4-benzothiazines and (or) the isomeric 2H-1,4-benzothiazines. 2-(4-Nitrophenacyl)-1H-benzimidazole and 2-phenacylbenzothiazole gave 4H-1,4-benzothiazines which are not liable to isomerize but the reaction of the first compound is complicated by a hydrolytic fission which yields 2-[2-(4-nitrobenzoylamino)phenylthiomethyl]benzimidazole. A mixture of dimethylsulfoxide, acetic acid, and water was used as oxidant and solvent. The effect of the substituent and of the solvent on the tendency of the products to undergo prototropic isomerization in the benzothiazine ring have been studied. 相似文献
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Salt effects on macrophase separations in non‐stoichiometric mixtures of oppositely charged macromolecules: Theory and experiment 下载免费PDF全文
A. E. Machinskaya L. Leclercq M. Boustta M. Vert V. V. Vasilevskaya 《Journal of Polymer Science.Polymer Physics》2016,54(17):1717-1730
In the field of biological applications, polyelectrolyte complexes are proposed to encapsulate bioactive compounds, to deliver drugs, and also to transfect genes into cells under the name of polyplexes. Complex formation is obtained by addition of a polycation solution into a polyanion solution or vice‐versa. This work proposes a theoretical approach to describe complex formation in the case of non‐stoichiometric mixtures of oppositely charged macroions having different degrees of ionization and different degrees of polymerization under different salt conditions. In a second part, comparison was made with experimental data collected when a weak polybase, namely poly(l ‐lysine) under its bromide form was added stepwise to solutions of various polyanions under their sodium salt form, namely poly(l ‐lysine citramide imide), poly(l ‐lysine citramide), and poly(β‐malic acid), the latter lacking hydroxyl groups attached to the main chain. The stability of stroichiometric complexes made of poly(l ‐lysine) and poly(l ‐lysine citramide) having different molecular masses is discussed. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1717–1730 相似文献
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An alternative approach to an AB2 monomer, N‐[3,5‐bis(4‐hydroxybenzoyl)benzene]‐4‐fluorophthalimde, 4, for hyperbranched poly(arylene ether ketone imide)s has been developed. The key steps were a para‐position selective electrophilic aromatic substitution of fluorobenzene with 5‐nitroisophthaloyl dichloride and a subsequent clean conversion of the aryl fluorides to phenol groups using potassium hydroxide as the nucleophile. The overall yield for the synthesis of 4 was 51.6%. 相似文献
69.
Zhengxiao Zhang Prof. Eiji Nakata Dr. Huyen Dinh Dr. Masayuki Saimura Prof. Arivazhagan Rajendran Prof. Kazunari Matsuda Prof. Takashi Morii 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(72):18118-18128
Recognition-driven modification has been emerging as a novel approach to modifying biomolecular targets of interest site-specifically and efficiently. To this end, protein modular adaptors (MAs) are the ideal reaction model for recognition-driven modification of DNA as they consist of both a sequence-specific DNA-binding domain (DBD) and a self-ligating protein-tag. Coupling DNA recognition by DBD and the chemoselective reaction of the protein tag could provide a highly efficient sequence-specific reaction. However, combining an MA consisting of a reactive protein-tag and its substrate, for example, SNAP-tag and benzyl guanine (BG), revealed rather nonselective reaction with DNA. Therefore new substrates of SNAP-tag have been designed to realize sequence-selective rapid crosslinking reactions of MAs with SNAP-tag. The reactions of substrates with SNAP-tag were verified by kinetic analyses to enable the sequence-selective crosslinking reaction of MA. The new substrate enables the distinctive orthogonality of SNAP-tag against CLIP-tag to achieve orthogonal DNA-protein crosslinking by six unique MAs. 相似文献
70.
An expeditious synthesis of aryl substituted E‐homoallylic bromides has been accomplished by the cleavage of cyclopropylcarbinols with phosphorus tribromide. 相似文献