Condensed cinnolines hold great interest in light of the broad spectrum of their useful properties [1]. The major method for constructing such heterocyclic systems involves intramolecular cyclization of aryldiazonium salts [1]. This approach has been used for the synthesis of such condensed heterocyclic systems as benzo [c]cirmolines [1, 2] and thieno-[2,3-c(3,2-c)]cirmolines [3]. However, o-aryl-or o-hetarylanilines, the starting compounds for these syntheses, are usually difficult to obtain. This lack of availability has limited the compounds of this class, as described [1].In the present work, we propose a new approach for construction of the cinnoline system involving formation of a -N=N-double bond by the reaction of NH 2 and NO 2 groups in P(OEt) 3. lntermolecular reactions of this type leading to arylazo compounds have not yet been reported. A similar method has been proposed for ring closure in 2-amino-2'-nitrodiphenyl, which, upon treatment with trimethylbenzylammonium hydroxide, gives a cyclic azoxy compound, namely, benzo[c]cinnoline oxide [4, 5].Previously unreported 3-amino-2-(2-nitrophenyl)thieno[2,3-b]pyridines (Ia-Ig, see Scheme) were selected as the starting compounds for the synthesis of fused cinnolines. Several published studies have been devoted to the synthesis of analogous compounds (R 1, R 2, R 3 = H, Me, R 4 = H, R 5 = NO2) containing a 4-nitrophenyl substituent by cyclization of the corresponding 2-(4-nitrobenzyl)thio-3-cyanopyridines in the presence of sodium ethylate in ethanol [6][7][8].According to the proposed scheme, alkylation of deprotonated 3-cyano-l(2H)-pyridinethiones (IIa-IIg) by 2-or 4-nitrobenzyl bromide leads to benzylthiopyridines (llIa-llIg). The next step involves deprotonation of the acidic methylene group in III by the action of KOH as a base and subsequent closure of the thiophene ring by a Thorpe-Ziegler reaction to give thienopyridines (Ia-Ig). We have shown that the nitrophenyi group in this case is also a sufficiently strong electron-withdrawing substituent for carrying out such a cyclization. The feasibility of obtaining I directly from starting pyridinethiones II without isolation of intermediate pyridines III is not excluded though isolation of the intermediate is desirable for obtaining the desired thienopyridine in pure form and good yield.The PMR and IR spectral data were sufficiently informative to establish the structures of I and III. Thus, the IR spectra of pyridines III have a band for the 3-CN group in the vicinity of 2220 cm -l. This band disappears after closure of the thiophene ring and formation of I and several bands appear at -3360 cm-1 characteristic for the NH 2 group. The PMR signal for the methylene group in pyridines III at -4.80 ppm is also diagnostic. This signal is lacking in the spectra of I, and a broad singlet at 4.50-6.00 ppm appears for the amino group.
Knowledge is now recognized as the driving force behind economic growth and productivity. The purpose of the article is study of the theory and practice of knowledge management as the basis for the competitive advantage of a modern organization on the example of a specific institution of higher education — Astrakhan State University. The methodological basis was a categorical apparatus of the knowledge management system, methods of description, analysis, synthesis, content analysis, as well as a systematic approach in relation to the description of the experience of a particular university. As part of the study, the systematization of theoretical views on the management of explicit and implicit knowledge was carried out, the features of this process in the higher education system were studied, and the barriers that prevent the free transfer of knowledge in organizations of this type were identified. The data considered in the article can be used in the institutions of higher education in Russia in the development of strategies in the relevant field of activity.
The growing amount of image data (produced in a multitude of different ways – for example, like photo albums from various events) and lack of a direct search method for image information frequently create a situation in which end users of the service that publishes such data want to find themselves but cannot do it faster than looking through all entries one by one. The objective of this study is to develop and implement an approach that would be able to process this kind of data source and extract images similar to those provided by end-users in an on-demand manner. To this end, the modern methods for extract and compressing faces are introduced and applied.
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