S ynthesis of SO۴۲-/ TiO۲ and SO۴۲-/ TiO۲/SiO۲ as nano-catal ysts for O -acyla tion of ph enol

Acylation of phenol is one of the most important reactions in organic synthesis. The use of the solid acid catalys ts such as clays, zeolites, ion excha nge resins and metal oxides are ga ining more attention in the chemical reactions. Since liquid acids such as H۲SO۴, HCl, H۳PO۴ and so on are highly corrosive, hazardous and po lluting; rece ntly, a number of organ ic synthesis have been c onducted with solid aci ds [۱,۲]. Th e solid acids are less toxic and facilitate to recovery and recycling of the catalysts. They also can remain stable even at high temperature an d in a solid-liquid syste m [۳,۴]. Ho wever, the S O۴۲-/TiO۲ also have so me disadvan tage such as low surface areas and wide pore d istributions. Compared with SO۴۲-/TiO۲, SO۴۲- / TiO۲/SiO۲ nano-catalyst had high specific surface area. I n this paper, SO۴۲-/TiO ۲ and SO۴۲-/ TiO۲/SiO۲ nano-catalyst were prep ared using the sol-gel method and were used f or the O-acylation of phenolwith acetic anhyd ride.

کلیدواژه ها:

Solid acid ، nano-catalyst ، O- acylation of phenol