Silica-supported aluminum chloride as catalyst for the tetrahydropyranylation of thymol

R. CÁMERA, R. RIMADA, G. ROMANELLI, J. AUTINO, P. VÁZQUEZ

CATALYSIS TODAY

Elsevier

Lugar: Amsterdam; Año: 2008 vol. 133 p. 822 - 827

0920-5861

The preparation, characterization, and performance of catalysts based on AlCl3 and different silica for the tetrahydropyranylation of thymol are reported. These catalysts were obtained by two procedures: incipient wetness impregnation and functionalization; in addition, the reaction was tested at 20°C, using toluene as solvent. Thymol is a natural product of the terpene family and is currently used as disinfectant. All silica-supported aluminum chlorides showed catalytic activity and, under these conditions, secondary products were not obtained. From the point of view of conversion and reuse, the best catalysts were SiO2(AR106)-I and SiO2(SG)-F. For the former catalyst, the conversion in its third reuse was 83%, while SiO2(SG)-F presented a conversion of 95% in its second reuse. The catalytic system represents a clean way to obtain the tetrahydropyranylation of phenol using AlCl3 because the catalyst can be recycled.