1232-99-1Relevant articles and documents
Zirconium(IV) chloride as versatile catalyst for the expeditious synthesis of quinoxalines and pyrido[2,3-b]pyrazines under ambient conditions
Aghapoor, Kioumars,Darabi, Hossein Reza,Mohsenzadeh, Farshid,Balavar, Yadollah,Daneshyar, Hesam
, p. 49 - 53 (2010)
Among the various transition metal chlorides, zirconium(IV) chloride was found to be an efficient catalyst for the rapid synthesis of a wide range of 2,3-dialkyl- and 2,3-diaryl-quinoxaline and pyrido[2,3-b]pyrazine derivatives in excellent yields at room temperature. The remarkable features of this catalytic process are the mild reaction conditions, quantitative yields, short reaction times, high conversions, tolerability of various functional groups, clean reaction profiles, and operational simplicity. Graphical Abstract: Among the various transition metal chlorides, zirconium(IV) chloride was found to be an efficient catalyst for the rapid synthesis of a wide range of 2,3-dialkyl- and 2,3-diaryl-quinoxaline and pyrido[2,3-b]pyrazine derivatives in excellent yields at room temperature. The remarkable features of this catalytic process are the mild reaction conditions, quantitative yields, short reaction times, high conversions, tolerability of various functional groups, clean reaction profiles, and operational simplicity.
Green oxidations: Titanium dioxide induced tandem oxidation coupling reactions
Jeena, Vineet,Robinson, Ross S.
, (2009)
The application of titanium dioxide as an oxidant in tandem oxidation type processes is described. Under microwave irradiation, quinoxalines have been synthesized in good yields from the corresponding α-hydroxyketones.
A recyclable solid acid catalyst sulfated titania for easy synthesis of quinoxaline and dipyridophenazine derivatives under microwave irradiation
Krishnakumar, Balu,Swaminathan, Meenakshisundaram
, p. 1261 - 1266 (2011)
TiO2SO42, prepared by solgel method has been used for the synthesis of quinoxaline and dipyridophenizine derivatives under microwave irradiation. High-resolution transmission electron microscope (HR-TEM) and atomic force m
The Re(I) coordination chemistry of a series of pyrido[2,3-b]pyrazine-derived ligands: Syntheses, characterisation and crystal structures
Yeo, Benjamin R.,Hallett, Andrew J.,Kariuki, Benson M.,Pope, Simon J.A.
, p. 1088 - 1094 (2010)
Reaction of 2,3-diaminopyridine with one equivalent of a functionalised vicinal diketone, in ethanol, yields a series of ligands based upon the pyrido[2,3-b]pyrazine core. The ligands were characterised by 1H, 13C-{1H} NMR
Synthesis of quinoxalines by a carbon nanotube-gold nanohybrid-catalyzed cascade reaction of vicinal diols and keto alcohols with diamines
Shah, Nimesh,Gravel, Edmond,Jawale, Dhanaji V.,Doris, Eric,Namboothiri, Irishi N. N.
, p. 57 - 61 (2015)
A one-pot oxidation-condensation method for the synthesis of quinoxalines from readily available benzoins or benzhydrols and 1,2-phenylenediamines or 2,3-diaminopyridine by use of a gold-carbon nanotube nanohybrid as a heterogeneous catalyst is reported. Quinoxalines are formed under mild conditions in air and in excellent yields. The simple and efficient methodology offers a safe and sustainable alternative to conventional acid and/or base-catalyzed thermal processes.
Glycerin and CeCl3 7H2O: A new and efficient recyclable reaction medium for the synthesis of quinoxalines
Venkat Narsaiah,Kranthi Kumar
, p. 883 - 892 (2012)
An efficient and environmentally benign process for the synthesis of quinoxalines has been developed using glycerine-cerium chloride as a reaction medium. This method is applicable to a variety of diketones and 1,2-phenylenediamines to afford the corresponding quinoxaline derivatives in excellent yields. The reaction medium was recovered and reused for further reactions without any problem. Taylor & Francis Group, LLC.
Sustainable approach to tandem catalysis: Expedient access to quinoxalines and pyrido[2,3-b]pyrazines from α-hydroxyketones via microwave-induced [(NH4)6Mo7O24·4H 2O - PEG 300] polar paste catalyst system
Aghapoor, Kioumars,Mohsenzadeh, Farshid,Mohebi Morad, Mina,Darabi, Hossein Reza
, p. 764 - 767 (2012)
[(NH4)6Mo7O24·4H 2O-PEG 300] is introduced as a polar paste catalyst system for tandem synthesis of quinoxalines and pyrido[2,3-b]pyrazines under open-vessel focused microwave irradiation. Low conversions were obtained when catalyst or PEG was used individually. Accordingly, a convenient combination of catalyst and PEG mostly led to quantitative yield of products within 15 min microwave irradiation with good turnover frequency values (11-20 h-1) taking a tandem process into consideration. The salient features of this environmentally benign method are fast conversions, high product selectivity and the use of a low-cost, readily available, nontoxic, catalyst and medium.
A recyclable and highly effective sulfated TiO2-P25 for the synthesis of quinoxaline and dipyridophenazine derivatives at room temperature
Krishnakumar,Swaminathan
, p. 2572 - 2577 (2010)
Sulfated TiO2-P25 has been prepared using H2SO 4 and used for the synthesis of quinoxaline and dipyridophenazine derivatives. Sulfate loading by H2SO4 increases the Lewis acidity of TiO2-P2
ZrOCl2.8H2O in water: An efficient catalyst for rapid one-pot synthesis of pyridopyrazines, pyrazines and 2,3-disubstituted quinoxalines
Bardajee, Ghasem Rezanejade
, p. 872 - 877 (2013)
Zirconium(IV) oxide chloride was found to be a rapid and efficient catalyst for the synthesis of pyrazines and 2,3-disubstituted quinoxalines in water. A variety of pyridopyrazine and 2,3-disubstituted quinoxaline derivatives are readily prepared in high yields under green conditions by cyclocondensation of the desired 1,2-diamine and 1,2-diketone using a catalytic amount of zirconium(IV) oxide chloride in water. Less active diamines, such as 2,3- and 3,4-diaminopyridines took part in this protocol to provide the desired products in good to excellent yields.
Microwave-assisted solvent-free synthesis and in vitro antibacterial screening of quinoxalines and pyrido[2, 3b]pyrazines
Morales-Castellanos, J. Jesus,Ramirez-Hernandez, Karina,Gomez-Flores, Nancy S.,Rodas-Suarez, Oscar R.,Peralta-Cruz, Javier
, p. 5164 - 5176 (2012)
We report herein the microwave assisted synthesis, without solvents and catalysts, of 6-substituted quinoxalines and 7-substituted pyrido[2,3b] pyrazines. The compounds were obtained in good yields and short reaction times using the mentioned procedure and two new structures are reported. A complete 1H-and 13C-NMR assignment was performed using 1D and 2D-NMR. Additionally, an in vitro screening was performed on Gram-positive and Gram-negative bacteria using amoxicillin as positive reference. Compounds bearing a pyridyl group tended to have higher antibacterial activity, but the best activity against Bacillus subtilis and Proteus mirabilis was observed with quinoxaline derivatives.
