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51.
Kavitha Kotthireddy Srikrishna Devulapally Pramod Kumar Dubey Aparna Pasula 《Journal of heterocyclic chemistry》2019,56(3):938-946
A facile, convenient, and adequate method has been developed for the synthesis of novel 5‐amino‐3‐(2‐oxo‐2H‐chromen‐3‐yl)‐7‐aryl‐7H‐thiazolo[3,2‐a]pyridine‐6,8‐dicarbonitriles ( 6 ) by employing 2‐(4‐(2‐oxo‐2H‐chromen‐3‐yl)thiazol‐2‐yl)acetonitrile ( 3 ) as an important precursor. Initially, we have synthesized the target compounds in a stepwise manner and then approached a tandem method to examine the feasibility of one‐pot method. Subsequently, one‐pot three‐component protocol has been established for the synthesis of title compounds by the reaction of 3 with benzaldehyde and malononitrile in refluxing ethanol engender a new six‐membered thiazolo[3,2‐a] pyridine as a hybrid scaffold. Reaction conditions were optimized for this reaction and a broad substrate scope with various aryl and heteroaryl aldehydes make this protocol very practical, attractive, and worthy. Mechanistic aspects for the formation of these compounds were outlined comprehensively. Characterization of these newly synthesized compounds was achieved by means of IR, 1H NMR, 13C NMR, and HRMS. 相似文献
52.
Rajeev K. Dubey Marja Niemi Kimmo Kaunisto Alexander Efimov Nikolai V. Tkachenko Helge Lemmetyinen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(21):6791-6806
Novel bay‐functionalized perylene diimides with additional substitution sites close to the perylene core have been prepared by the reaction between 1,7(6)‐dibromoperylene diimide 6 (dibromo‐PDI) and 2‐(benzyloxymethyl)pyrrolidine 5 . Distinct differences in the chemical behaviors of the 1,7‐ and 1,6‐regioisomers have been discerned. While the 1,6‐dibromo‐PDI produced the corresponding 1,6‐bis‐substituted derivative more efficiently, the 1,7‐dibromo‐PDI underwent predominant mono‐debromination, yielding a mono‐substituted PDI along with a small amount of the corresponding 1,7‐bis‐substituted compound. By varying the reaction conditions, a controlled stepwise bis‐substitution of the bromo substituents was also achieved, allowing the direct synthesis of asymmetrical 1,6‐ and 1,7‐PDIs. The compounds were isolated as individual regioisomers. Fullerene (C60) was then covalently linked at the bay region of the newly prepared PDIs. In this way, two separate sets of perylene diimide–fullerene dyads, namely single‐bridged (SB‐1,7‐PDI‐C60 and SB‐1,6‐PDI‐C60) and double‐bridged (DB‐1,7‐PDI‐C60 and DB‐1,6‐PDI‐C60), were synthesized. The fullerene was intentionally attached at the bay region of the PDI to achieve close proximity of the two chromophores and to ensure an efficient photoinduced electron transfer. A detailed study of the photodynamics has revealed that photoinduced electron transfer from the perylene diimide chromophore to the fullerene occurs in all four dyads in polar benzonitrile, and also occurs in the single‐bridged dyads in nonpolar toluene. The process was found to be substantially faster and more efficient in the dyads containing the 1,7‐regioisomer, both for the singly‐ and double‐bridged molecules. In the case of the single‐bridged dyads, SB‐1,7‐PDI‐C60 and SB‐1,6‐PDI‐C60, different relaxation pathways of their charge‐separated states have been discovered. To the best of our knowledge, this is the first observation of photoinduced electron transfer in PDI‐C60 dyads in a nonpolar medium. 相似文献
53.
Trichloroisocyanuric acid–KF afforded dialkylfluorophosphates from dialkylphosphites at room temperature through a facile electrophilic–nucleophilic metathesis. 相似文献
54.
The kinetics of oxidation of ethyldigol by vanadium(V) in aqueous acidic medium has been carried out. The reaction is first order with respect to vanadium(V) and the substrate and is acid catalysed.Hammett acidity function (H
0) andBunnett hypothesis have been applied. The formation of free radicals during the course of the reaction has been indicated. A probable reaction mechanism is proposed.
Die Kinetik der Oxidation von Ethyldigol mit Vanadium(V) in wäßrigem saurem Medium
Zusammenfassung Es wurde die Kinetik der Oxidation von Ethyldigol mittels Vanadium(V) in wäßriger saurer Lösung untersucht. Die Reaktion ist erster Ordnung bezüglich Vanadium(V) und Substrat und ist säurekatalysiert. Es wurden dieHammett-Aciditätsfunktion (H 0) und dieBunnett-Hypothese angewandt. Die Bildung von freien Radikalen während der Reaktion konnte bestätigt werden. Es wird ein Reaktionsmechanismus vorgeschlagen.相似文献
55.
Kar Aishwarya S. Rao Ankita Sahu Manjulata Kumar Shiny S. Tomar B. S. 《Journal of Radioanalytical and Nuclear Chemistry》2017,314(3):1667-1674
Journal of Radioanalytical and Nuclear Chemistry - Plutonium recovery is inevitable from plutonium bearing alumina crucibles generated over the years as part of carbon analysis during chemical... 相似文献
56.
Vinay K. Singh Rahul Dubey Abhishek Upadhyay Laxmi Kant Sharma Rana Krishna Pal Singh 《Tetrahedron letters》2017,58(45):4227-4231
An efficient and economical method was developed for synthesis of 3-substituted indole by using electrochemically induced condensation of various aldehyde, indole and malononitrile. 相似文献
57.
Quinazoline is a heterocyclic compound having biological activities. It is aromatic in nature having bicyclic structure containing benzene ring and pyrimidine ring. Quinazoline and its derivatives are found to have wide range of biological activities that is anticancer, analgesic, antimicrobial, antihypertensive, anticonvulsant, antimalarial, antitumor, and anti-tubercular activities. The purpose of this review is to highlight the recent researches made by researchers on various biological activities of quinazoline derivatives on different targets. 相似文献
58.
G. Vasuki V. Parthasarathi K. Ramamurthi D. P. Jindal S. Dubey 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1062-1063
The title compound, C25H31NO2·H2O, has the outer two six‐membered rings in chair conformations, while the central ring is in an 8β,9α‐half‐chair conformation. The five‐membered ring adopts a 13,14‐half‐chair conformation. The pyridylmethylene moiety has an E configuration with respect to the carbonyl group at position 17. The structure is stabilized by intermolecular O—H?N and O—H?O hydrogen bonds. 相似文献
59.
We aim to extend some results in [6, 7, 8, 2] on two person zero sum matrix games (TPZSMG) with fuzzy goals and fuzzy payoffs to I-fuzzy scenario. Because the payoffs of the matrix game are fuzzy numbers, the aspiration levels of the players are fuzzy as well. It is reasonable to believe that there is some indeterminacy in estimating the aspiration levels of both players from their respective expected pay offs. This situation is modeled in the game using Atanassov??s I-fuzzy set theory. A new solution concept is proposed for such games and a procedure is outlined to obtain the degrees of suitability of the aspiration levels for each of the two players. 相似文献
60.