| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 49847 | Catalysis Communications | 2012 | 4 Pages |
Friedel–Crafts acylation of indole with acetic anhydride has been carried out over zeolites under microwave and conventional heating, respectively. A tungstophosphoric acid modified Hβ (PW-Hβ) zeolite showed better catalytic performance than parent Hβ zeolite due to its higher amount of strongly acidic sites and lower amount of Lewis acid sites, confirmed from NH3 temperature-programmed desorption (NH3-TPD) and Fourier Transform Infrared Spectrometer after adsorption of pyridine (Py-IR). Particularly, microwave radiation was found to make this transformation not only more efficient but also selective to 3-acetylindole compared with conventional heating. Furthermore, PW-Hβ has shown good stability in this reaction.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Friedel–Crafts acylation of indole with acetic anhydride was studied over zeolites. ► Microwave was believed to make this transformation more efficient and selective. ► Tungstophosphoric acid modified Hβ was proven to have good activity and stability. ► Synergistic effect of Hβ zeolite and WO3 accounts for the catalyst's high activity. ► A possible mechanism was proposed based on GC-MS results and previous literature.
