NISCAIR Online Periodicals Repository

Research Journals >
Indian Journal of Chemical Technology (IJCT) >
IJCT Vol.15 [2008] >
IJCT Vol.15(3) [May 2008] >

Title: Clean and efficient synthesis of coumarins over modified metal oxides via Pechmann reaction
Authors: D’Souza, Joyce
Nagaraju, N
Keywords: Pechmann reaction
Solid acids
Metal oxides
Sulphate-modified zirconia
Borate-modified zirconia
Phosphate-modified zirconia
Issue Date: May-2008
Publisher: CSIR
Abstract: The catalytic activity of solid acids such as zirconia, alumina and silica and their SO₄²⁻,PO₄³⁻ and BO₃³⁻ modified forms has been studied in the Pechmann reaction between resorcinol and ethylacetoacetate under solvent-free liquid phase reflux conditions and autogenous pressure.A systematic study of this reaction has been made by varying the following parameters: catalyst, amount of catalyst, duration and temperature of reaction and molar ratio of reactants. Under refluxing conditions, in the presence of sulphated zirconia, the percentage yield of the product, 7-hydroxy 4-methyl coumarin was in the range of 30-75% which, however, contained many impurities. When the same reaction was conducted in an autoclave at 150ºC, the clean product of yields upto 99% was obtained. Other phenols used in this work include catechol, hydroquinone, m-cresol, p-cresol, o-cresol, pyrogallol, phloroglucinol, orcinol, m-aminophenol and phenol.The sites of higher acid strength and perhaps super-acidic sites on the catalyst appear to be catalyzing the formation of coumarins via Pechmann reaction. Sulphated zirconia is found to be a promising catalyst for this reaction under autogenous conditions.
Page(s): 244-251
ISSN: 0971–457X
Source:IJCT Vol.15(3) [May 2008]

Files in This Item:

File Description SizeFormat
IJCT 15(3) (2008) 244-251.pdf275.85 kBAdobe PDFView/Open
 Current Page Visits: 112 
Recommend this item


Online Submission of Articles |  NISCAIR Website |  National Knowledge Resources Consortium |  Contact us |  Feedback

Disclaimer: NISCAIR assumes no responsibility for the statements and opinions advanced by contributors. The editorial staff in its work of examining papers received for publication is helped, in an honorary capacity, by many distinguished engineers and scientists.

CC License Except where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India

Copyright © 2015 The Council of Scientific and Industrial Research, New Delhi. All rights reserved.

Powered by DSpace Copyright © 2002-2007 MIT and Hewlett-Packard | Compliant to OAI-PMH V 2.0

Home Page Total Visits: 167523 since 01-Sep-2015  Last updated on 28-Jun-2016Webmaster: