- Efficient multi-component synthesis of highly substituted imidazoles utilizing P2O5/SiO2 as a reusable catalyst
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Phosphorus pentoxide supported on silica gel (P2O 5/SiO2) has been used as an efficient and reusable catalyst for the one-pot pseudo four-component synthesis of 2,4,5-trisubstituted imidazoles from benzil or benzoin, aldehydes, and ammonium acetate. It was also used for four-component preparation of 1,2,4,5-tetrasubstituted imidazoles from benzil or benzoin, aldehydes, primary amine, and ammonium acetate under thermal solvent-free conditions. The remarkable features of this new procedure are high conversions, cleaner reaction, simple experimental and work-up procedures and also the catalyst can be easily separated from the reaction mixture and reused several times without any loss of its activity.
- Shaterian, Hamid Reza,Ranjbar, Mohammad,Azizi, Kobra
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experimental part
p. 1635 - 1645
(2012/01/06)
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- Synthesis of highly substituted imidazoles using Bronsted acidic ionic liquid, triphenyl(propyl-3-sulphonyl)phosphonium toluenesulfonate, as reusable catalyst
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Bronsted acidic ionic liquid, triphenyl(propyl-3-sulphonyl) phosphonium toluenesulfonate, has been used as an efficient and reusable catalyst for the one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles under solvent-free conditions in excellent yields.
- Shaterian,Ranjbar,Azizi
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experimental part
p. 1120 - 1134
(2012/02/04)
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