Artigo Publicado em Periódico
Friedel–Crafts acylation of anisole with acetic anhydride over silica-supported heteropolyphosphotungstic acid (HPW/SiO2)
Fecha
2004Registro en:
1381-1169
v. 209, n. 1-2
Autor
Cardoso, Luiz Augusto Martins
Alves Junior, Walter
Gonzaga, Angélica Raimunda Esquerdo
Aguiar, Leila Maria Guimaraes
Andrade, Heloysa Martins Carvalho
Cardoso, Luiz Augusto Martins
Alves Junior, Walter
Gonzaga, Angélica Raimunda Esquerdo
Aguiar, Leila Maria Guimaraes
Andrade, Heloysa Martins Carvalho
Institución
Resumen
Methoxyacetophenones were synthesized through Friedel–Crafts acylation of anisole with acetic anhydride using a silica-supported heteropolyphosphotungstic acid (HPW) catalyst. High conversions and very high p-selectivity were attained in the temperature range of 61–110 °C.Nevertheless, the catalyst seemed to deactivate after half an hour at 61 and 83 °C, mainly due to strong but reversible adsorption of products. Cleaning the spent catalyst recovered the activity, indicating that it was stable under the experimental conditions and that the active HPW was not fairly leached from the silica support. In spite of this, the slower but progressive coking deactivated the catalyst.