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Acylation of aromatic compounds by acid anhydrides using Preyssler's anion [NaP5W30O110]14-and heteropolyacids as green catalysts

100%
Gharib A., Jahangir M., Scheeren J.
Polish Journal of Chemical Technology
|
2011
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vol. 13
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issue 2
11-17
EN
The Preyssler, Wells-Dowson and Keggin heteropolyacids are efficient and eco-friendly solid acid catalysts for the acylation of electron-rich aromatic compounds with acid anhydrides. The performance of different forms of heteropolyacids was compared. In all the cases, the best results were obtained using the Preyssler heteropolyacid as the catalyst. In the presence of 25 mol% (with respect to H+ equivalency) Preyssler catalyst, highly para-selective acetylation of anisole occurs using two equivalents of acetic anhydride, in 15 min at room temperature. The isolated yield of the p-methoxyacetophenone product is 98%.
2
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Novel catalytic method synthesis of calix[4]pyrroles using Preyssler and Wells-Dawson heteropolyacids

100%
Gharib A., Jahangir M., Scheeren J.
Polish Journal of Chemical Technology
|
2011
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vol. 13
|
issue 2
70-73
EN
A catalytic synthesis of calix[4]pyrroles and N-confused calix[4]pyrroles by reaction of dialkyl or cycloalkyl ketones with pyrrole was performed using Preyssler, sodium30-tungsto pentaphosphate, [NaP5W30O110]14- and Wells-Dawson heteropolyacids as acidic catalysts. The process occurred under mild, eco-friendly and environmental friendly conditions and as a reusable, green catalyst at room temperature for 6 hours. The results showed that the yield for this synthesis is excellent with the use of Preyssler and Wells-Dawson type tungstophosphoric heteropolyacid, H6[P2W18O62], catalysts. The synthesis reaction of calix[4]pyrroles and N-confused calix[4]pyrroles was developed using different solvents and the best yields were obtained in chloroform.
3
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Acetylation ofp-Aminophenol by Preyssler's anion [NaP5W30O110]14-, [NaP5W29MoO110]14-with green condition at room temperature

88%
Gharib A., Scheeren J., Bamoharram F., Roshani M., Jahangir M.
Polish Journal of Chemical Technology
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2009
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vol. 11
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issue 2
31-35
EN
Synthesis of acetaminophen at green condition and room temperature in the presence of the Preyssler type heteropolyacids has been investigated in order to contribute toward clean technology, which is the most important need of the society. All of the catalysts are recyclable and reusable.
4
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One-pot synthesis of (S)-2-(6-methoxynaphtalen-2-yl)propanoic acid, (S)-Naproxen using Preyssler and Keggin-type heteropolyacids as green and reusable catalysts

76%
Gharib A., Daneshtalab M., Scheeren J., Bamoharram F., Roshani M., Jahangir M.
|
EN
A simple, clean and environmentally benign route to the enantioselective synthesis of (S)-2-(6-methoxynaphtalen-2-yl)propanoic acid, (S)-Naproxen 3 is described by using Preyssler heteropolyacid, H14[NaP5W30O110], as a green and reusable catalyst in water and in the presence of 1-(6-methoxynaphthalen-2-yl)propan-1-one 1, D-mannitol 2. The products were obtained in very good yields.
5
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Novel catalytic synthesis of 6,7-dimethoxyisatin with the use of heteropolyacids (HPAs) as acid solid catalyst

76%
Gharib A., Daneshtalab M., Scheeren J., Bamoharram F., Roshani M., Jahangir M.
|
EN
An efficient method for the preparation of 6,7-dimethoxyisatin and its derivatives was developed with good yield by using Preyssler-type heteropolyacid (HPA) as acid catalyst under green conditions. The comparison between Keggin type heteropolyacids, H3[PW12O40], H4[SiW12O40] and H4[SiMo12O40], H3[PMo12O40] and mineral acids with Preyssler's anion shows that the latter possess better catalytical activity than the other heteropolyacids and no degradation of the structure was observed.
6
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Catalytic synthesis of warfarin acetals by using different heteropolyacid catalysts

76%
Gharib A., Jahangir M., Roshani M., Scheeren J., Mohadeszadeh S., Bakhtiari L., Lagzian S.
Polish Journal of Chemical Technology
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2011
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vol. 13
|
issue 3
5-11
EN
In this research, we report on the synthesis of warfarin acetals by using Preyssler's anion, [NaP5W30O110]-14 and heteropolyacids (HPAs) catalysts. This reaction was performed using methanol and ethanol at reflux temperature conditions. Under these conditions we have excellent yields and high selectivity. Preyssler heteropolyacid catalyst were easily recycled recovery and reused without the loss of its catalytic activities. The synthesis of warfarin acetals has been achieved using the catalytic amounts of green, inexpensive and eco-friendly Keggin types heteropolyacids. The products were obtained in high yields.
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