01919nas a2200205   4500008004100000022001400041245018300055210006900238260007300307300001200380490000600392520104200398653002401440653004001464653002501504100001901529700002001548700001801568856012701586       2007                        eng d  a1566-736700aBenzylsulfonic acid functionalized mesoporous Zr-TMS catalysts: an efficient and recyclable catalyst for the preparation of coumarin derivatives by pechmann condensation reaction0 aBenzylsulfonic acid functionalized mesoporous ZrTMS catalysts an  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY  a777-7830 v83 a<p>Benzylsulfonic acid functionalized mesoporous Zr-TMS (Zr-TMS-BSA, Zr-TMS, zirconia based transition metal oxide mesoporous molecular sieves) catalyst is used as an alternative to conventional acid catalysts in the von Pechmann condensation of aromatic alcohols with ethyl acetoacetate leading to the formation of coumarin derivatives in solvent free condition at 150 degrees C. Three types of coumarins, 7-hydroxy-4-methylcoumarin (beta-methylumbelliferone), 7-methoxy-4-methylcoumarin (Methyl-4-methylumbelliferyl ether) and 7,8-benzo-4-methylcoumarin derivatives have been prepared using resorcinol, 3-methoxyphenol and 1-naphthol, respectively. The catalytic activity and the recycle studies of the catalyst in all the three reactions proved the superior performance of the catalyst. Further the products were confirmed by GC, elemental analysis, melting point and NMR techniques. Finally, the probable mechanism for Pechmarm condensation using Zr-TMS-BSA catalyst has been reported. (c) 2006 Elsevier B.V. All rights reserved.</p>10abenzylsulfonic acid10aPechmann condensation and coumarins10aZr-TMS-BSA catalysts1 aSelvakumar, S.1 aChidambaram, M.1 aSingh, A., P.  uhttps://library.ncl.res.in/content/benzylsulfonic-acid-functionalized-mesoporous-zr-tms-catalysts-efficient-and-recyclable01855nas a2200193   4500008004100000022001400041245008100055210006900136260005700205300001200262490000800274520115200282653002801434653002301462653002401485100001901509700001801528856011501546       2009                        eng d  a1011-372X00aBenzoylation of anisole over silicotungstic acid modified mesoporous alumina0 aBenzoylation of anisole over silicotungstic acid modified mesopo  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcMAR  a363-3720 v1283 a<p>Mesoporous alumina (MA) molecular sieves were synthesized by using aluminum sec-butoxide as Al precursor and lauric acid as the structure directing agent. The synthesized MA was functionalized with silicotungstic acid (STA) via wet impregnation method and characterized by various physico-chemical techniques. The XRD patterns of a series of HPA functionalized MA are showing the ordered structures. N(2) sorption analysis shows type IV isotherm. NH(3)-TPD measurements revealed an increase in number of acid sites with an increase in loading of STA over MA. At the same time decrease in the acidity was observed with the increase in calcination temperature of the supported materials. Functionalization of STA were also carried out over different alumina supports such as catapol-B (CB) and alumina synthesized without surfactant (ASW) and their activities were evaluated by carrying out liquid phase Friedel-Craft acylation (FC) reaction of anisole with p-toluoyl chloride in a batch reactor at 120 degrees C. Recycling was performed in the FC reaction using 30 wt% STA-MA two times and no major deactivation of the catalyst was observed.</p>10aFriedel-Craft acylation10aMesoporous alumina10aSilicotungstic acid1 aSelvakumar, S.1 aSingh, A., P.  uhttps://library.ncl.res.in/content/benzoylation-anisole-over-silicotungstic-acid-modified-mesoporous-alumina-0