Syntheses, Cholinesterases Inhibition, and Molecular Docking Studies of Pyrido[2,3-<i>b</i>
]pyrazine Derivatives
作者:Abdul Hameed、Syeda T. Zehra、Syed J. A. Shah、Khalid M. Khan、Rima D. Alharthy、Norbert Furtmann、Jürgen Bajorath、Muhammad N. Tahir、Jamshed Iqbal
DOI:10.1111/cbdd.12579
日期:2015.11
molecular docking studies. The bioactivities data of pyrido[2,3-b]pyrazines showed 3-(3'-nitrophenyl)pyrido[2,3-b]pyrazine 6n a potent dual inhibitor among the series against both AChE and BChE with IC50 values of 0.466 +/- 0.121 and 1.89 +/- 0.05 mum, respectively. The analogues 3-(3'-methylphenyl)pyrido[2,3-b]pyrazine 6c and 3-(3'-fluorophenyl)pyrido[2,3-b]pyrazine 6f were found to be selective inhibition
A copper-catalyzed oxidative couplingreaction of o-phenylenediamines with 2-aryl/heteroarylethylamines using molecular oxygen as an oxidant has been developed. This approach provides a practical and direct access to construct quinoxalines in excellent yields at roomtemperature. The reaction has a broad substrate scope and exhibits excellent functional-group tolerance. This method could be easily
Tandem oxidation processes for the preparation of nitrogen-containing heteroaromatic and heterocyclic compounds
作者:Steven A. Raw、Cecilia D. Wilfred、Richard J. K. Taylor
DOI:10.1039/b315689c
日期:——
alpha-hydroxy ketones undergo manganese dioxide-mediated oxidation followed by in situ trapping with aromatic or aliphatic 1,2-diamines to give quinoxalines or dihydropyrazines, respectively, in a one-pot procedure which avoids the need to isolate the highly reactive dicarbonyl intermediates. The scope and limitations of these procedures are outlined and modifications to this procedure are discussed
The scope of homogeneous Lewis acid-catalyzed benzo[N,N]-heterocyclic condensation was expanded to include the use of various metal salts not reported in the literature and $SnCl_2\cdot}2H_2O$ was finally selected. Among various solid supports activated with $SnCl_2$, heterogeneous $SnCl_2/SiO_2$ proved to be the most effective and significantly higher conversions were achieved compared to $SnCl_2\cdot}2H_2O$ itself. The results of TG-DTA and BET indicated that dispersed $SnCl_2$ coordinates with surface hydroxyl groups of silica leading to formation of stable Lewis acid sites. Low catalyst loading, operational simplicity, practicability and applicability to various substrates render this eco-friendly approach as an interesting alternative to previously applied procedures.
An Efficient and Green Procedure for the Synthesis of Quinoxaline Derivatives using 3,5-Bis(trifluoromethyl)phenylammonium triflate (BFPAT) Organocatalyst
The application of 3,5-bis(trifluoromethyl)phenylammonium triflate (BFPAT) as a convenient new organocatalyst for the synthesis of quinoxaline derivatives is described. In the presence of BFPAT, one-pot synthesis of a wide variety of quinoxaline derivatives was achieved by the reaction of various o-phenylenediamines and 1,2-dicarbonyl compounds in water.