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Efficient synthesis of quinoxaline derivatives over ZrO2/MxOy (M = Al, Ga, In and La) mixed metal oxides supported on MCM-41 mesoporous molecular sieves

Paper ID Volume ID Publish Year Pages File Format Full-Text
42788 45941 2009 9 PDF Available
Title
Efficient synthesis of quinoxaline derivatives over ZrO2/MxOy (M = Al, Ga, In and La) mixed metal oxides supported on MCM-41 mesoporous molecular sieves
Abstract

Mesoporous Si-MCM-41 was synthesized by a hydrothermal crystallisation method. Various weight percentages of ZrO2/MxOy (where M = Al, Ga, In and La) mixed metal oxides were loaded by wet impregnation using methanol solutions. The characteristic structural features of the materials were determined by various physico-chemical techniques, such as XRD, BET surface area measurement, ammonia TPD, SEM and TEM. The regular meso structure of Si-MCM-41 with a uniform pore size is very well preserved after optimum loading of binary metal oxides. XRD patterns revealed the hexagonal nature of the support; it retained its structure with maximum loading of 17 wt.% ZrO2 and 4 wt.% MxOy mixed oxides. BET measurements show the abrupt decrease in surface area, pore size and pore volume at higher loading of metal oxides. TEM studies of the material shows regular arrangement of hexagonal pores present in the host Si-MCM-41 and the fine dispersion of metal oxides over the support. NH3-TPD experiments indicated the variations in the acid strength as the metal oxides were loaded. The acid strength of the catalysts follows the order: 17% ZrO2/4% Ga2O3/MCM-41 ≈ 17% ZrO2/4% Al2O3/MCM-41 > 17% ZrO2/4% La2O3/MCM-41 > 17% ZrO2/4% In2O3/MCM-41 > 17% ZrO2/MCM-41. Medicinally important quinoxaline derivatives were efficiently synthesized by the liquid phase condensation reaction of various 1,2-diamines with 1,2-diketones using the prepared catalysts. Various reaction parameters were optimized to improve product yield.

Graphical abstractVarious weight percentages of ZrO2/MxOy (where M = Al, Ga, In and La) mixed metal oxides were supported on Si-MCM-41 by a wet impregnation method. The characteristic structural features of the materials were probed by XRD, BET surface area, ammonia TPD, SEM and TEM techniques. Medicinally important quinoxaline derivatives were efficiently synthesized by the liquid phase condensation reaction of various 1,2-diamines with 1,2-diketones using the prepared catalysts.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
ZrO2/Ga2O3/MCM-41; Condensation; 1,2-Diamines; 1,2-Diketones; Quinaxaline derivatives
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Efficient synthesis of quinoxaline derivatives over ZrO2/MxOy (M = Al, Ga, In and La) mixed metal oxides supported on MCM-41 mesoporous molecular sieves
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 357, Issue 2, 15 April 2009, Pages 184–192
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us